clean coal technologies in japan.pdf

Clean Coal Technologies in Japan

New Energy and Industrial Technology Development Organization

Center for Coal Utilization, Japan

Toward the Technology Innovation in the Field of Coal Utilization

Toward the Technology Innovation in the Field of Coal Utilization

1


Preface�

Part1 Classification of CCT�

(1)Classification of CCT in Coal Flow

(2)Clean Coal Technology System

(3)Appreciation of CCT in Markets

(4)CCT in Japanese Industries

(5)Environmental Technologies

(6)International Cooperation

Part2 Outline of CCT�

(1) Coal Fired Power Generation Technologies�

A. Combustion Technologies�

1A1. Pulverized Coal Fired Power Generation Technology(Ultra Super Critical Steam)

1A2. Circulating Fluidized Bed Combustion Technology (CFBC)

1A3. Internal Circulating Fluidize Bed Combustion Technology (ICFBC)

1A4. Pressurized Internal Circulating Fluidized Bed Combustion Technology (PICFBC)

1A5. Coal Partial Combustor Technology (CPC)

1A6. Pressurized Fluidized Bed Combustion Technology (PFBC)

1A7. Advanced Pressurized Fluidized Bed Combustion Technology (A-PFBC)

B. Gasification Technologies�

1B1. Hydrogen-from-Coal Process (HYCOL)

1B2. Integrated Coal Gasification Combined Cycle (IGCC)

1B3. Coal Energy Application for Gas, Liquid and Electricity (EAGLE)

(2) Iron Making and General Industry Technologies�

A. Iron Making Technologies�

2A1. The Formed-Coke making Process (FCP)

2A2. Pulverized Coal Injection for Blast Furnace (PCI)

2A3. Direct Iron Ore Smelting Reduction Process (DIOS)

2A4. Super Coke Oven for Productivity and Environment Enhancement toward the 21st Century (SCOPE21)

B. General Industry Technologies�

2B1. Fluidized Bed Advanced Cement Kiln System (FAKS)

2B2. New Scrap Recycling Process (NSR)

(3) Multi-Purpose Coal Utilization Technologies�

A.Liquefaction Technologies�

3A1. Coal Liquefaction Technology Development in Japan

3A2. Bituminous Coal Liquefaction Technology (NEDOL)

3A3. Brown Coal Liquefaction Technology (BCL)

3A4. Dimethylether Production Technology (DME)

B. Pyrolysis Technologies�

3B1. Multi-Purpose Coal Conversion Technology (CPX)

3B2. Coal Flash Partial Hydropyrolysis Technology

C. Powdering, Flowing, and Co-utilization Technologies�

3C1. Coal Cartridge System (CCS)

3C2. Coal Slurry Production Technology

3C3. Briquette Production Technology

3C4. Coal and Woody Biomass Co-firing Technology

D. De-ashing and Reforming Technologies�

3D1. Hyper-Coal based High Efficiency Combustion Technology(Hyper Coal)

3D2. Low-Rank Coal Upgrading Technology (UBC Process)

(4) Environmental Protection Technologies�

A. Coal Ash Effective Use Technologies�

4A1. Coal Ash Generation Process and Application Fields

4A2. Effective use for Cement/Concrete

4A3. Effective use for Civil Engineering/Construction and Others

4A4. Valuable Resources Recovery Technologies for Coal Ash

B. Flue Gas Treatment and Gas Cleaning Technologies �

4B1. SOx Reduction Technology

4B2. NOx Reduction Technology

4B3. De-SOx and De-NOx Technology

4B4. Soot/dust Treatment Technology and Trace Elements Removal Technology

4B5. Gas Cleaning Technology

C. CO2 Recovery Technologies�

4C1. Hydrogen Production by Reaction Integrated Novel Gasification Process (HyPr-RING)

4C2. CO2 Recovery and Sequestration Technology

4C3. CO2 Conversion Technology

4C4. Oxy-fuel Combustion (Oxygen-firing of conventional PCF System)

(5) Basic Technologies for Advanced Coal Utilization�

5A1. Modelling and Simulation Technologies for Coal Gasification

(6) Coproduction System�

6A1. Co-generation System

6A2. Coproduction System

Part3 Future Outlook for CCT�

�

Mathematical Table

---------------------------------------------------------------------------2

-----------------------------------------------3

-------------------------------------3

----------------------------------------5

-----------------------------------------6

---------------------------------------------7

--------------------------------------------11

-----------------------------------------------12

-------------------------------------------------------13

----3

----15

----16

---17

---------------------19

---------------21

---23

-------------------------25

-------27

------29

----------------------31

-------------33

---------35

--37

------41

---------------------------39

--------43

----------45

--------------------47

-------------------49

-----------51

----------------53

---------------------------------------55

------------------------------56

--------------------------------57

-------------59

---61

----63

-------65

------------------------------67

--69

--------71

----------------------------------------73

----------------------------------------75

--------------------------------77

----79

------------------------------------------81

--83

----------------85

-------------------------------------86

--87

-----89

----------------------------------------------93

------------------------------------------------95

------------------------------------------97

------------------------------------------------------100

Fiscal year

2

Preface

Electric powergeneration

1.40

1.35

1.30

1.25

1.20

1.15

1.10

1.05

1.00

0.95

0.901990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 20022001

Coal consumption

Total primary energy supply GDP

CO2 emissions

Thermal power generation efficiency

CO2 emissions/GDP

New Energy and Industrial Technology Development Organization (NEDO) and Center for Coal Utilization, Japan (CCUJ) have jointly prepared this brochure to review the history of "Clean Coal Technology (CCT)" in Japan, to systematically describe the present state of CCT to the extent possible, and to enhance the activities toward novel technology innovation on the firm recognition of the present state.NEDO and CCUJ expect that the brochure will be helpful in understanding the CCT of Japan as an attractive technology in the current state of ever-increasing complexity of coal utilization owing to global warming and other environmental issues, and also expect that the brochure will become a starting point of the approaching rapid progress of CCT and the foundation of a coal utilization system.�As described herein, CCT progress in Japan has reached the world’s highest level of technological superiority, and consequently, the technology is exceptionally attractive for Asian countries which depend on coal as an energy source. In Japan, coal consumption has rapidly increased since 1998 with thermal power generation efficiency increasing from approximately 38% to 41% over the past decade. In addition, emissions of SOx and NOx per generated power unit from thermal power plants are far below the level of other industrialized countries. In this regard, CCT is expected to establish a worldwide system satisfying both economic and environmental conditions through the efforts of reducing CO2 emissions while maintaining economic growth.�Technological innovation has no boundaries, and unlimited progress is attained by sustainable and progressive efforts and by patient and continuous activities to accumulate the effects of technological development and to support an ever-advancing society. NEDO and CCUJ are confident that this brochure will be effective in CCT development and anticipate the emergence of epoch-making technological innovations in the coal utilization field.

Increase in coal consumption and trend of economy, environment, and energy in Japan (1990-2002)

Classification of CCT in Coal Flow

Part1 Classification of CCT

Mining, �crushing �

and pulverizingTransportation�

and storage

Processing, �reforming �

and converting

Coal mine

Coal tanker

CWM

3

Slurry preparation

Pulverizing/Briquetting

Carbonization

Gasification

DME/GTL

Liquefaction

Coal train

Classification

Anthracite

Bituminous

coal

Subbituminous

coal

Brown coal

Heating value (Kcal/kg(on dry basis))

-

8,400 or more

8,100 or more

7,800 or more

7,300 or more

6,800 or more

5,800 or more

Fuel ratio

4.0 or more

1.5 or more

1.5 or less

1.0 or more

1.0 or less

1.0 or more

1.0 or less

-

-

Caking property

Non-caking

Strong-caking

Caking

Weak-caking

Weak-caking

Non-caking

Non-caking

Non-caking

Classification of coal depending on the degree of carbonization

coki

ng c

oal

stea

m c

oal

coking coal A

coking coal B

coking coal C

coking coal D

steam coal A

steam coal B

steam coal C

Coal in the Trade Statistics

Anthracite

Ash content of 8% or less

Ash content of more than 8%






Strong-cakingcoal for coke

Other coal for coke

Other

Other coal

Indication in TEXT report

Anthracite

Coal classification depending on the utilizations (expressed as coal)

Bituminous coal

Specific Gravity

Apparent Specific Gravity

Specific heat

Thermal conductivity(W/m K)

Ignition point( )

Heating value(Kcal/kg(on dry basis))

1.5~1.8

-

0.22~0.24

-

400~450

8,200~8,500

1.2~1.7

0.75~0.80

0.24~0.26

1.26~1.65

300~400

7,500~8,800

0.8~1.5

0.55~0.75

0.26~0.28

-

250~300

5,500~7,500

Coal physical properties Multi-purpose utilization �technology

Liquefaction�technology

Gasification �technology

Deashing and reforming �technology

Basic technology�for advanced coal utilization

Pyrolysis

Pulvelization, fluidization �and co-utilization �technology

Anthracite Bituminous coal Brown coal

Brown Coal Liquefaction Technology (BCL)

Dimethylether Production Technology (DME)

Multi-purpose Coal Conversion Technology (CPX)

Coal Flash Partial Hydropyrolysis Technology

Coal Cartridge System (CCS)

Coal Slurry Production Technology

Briquette Production Technology

Modelling and Simulation Technologies for Coal Gasification

Coal and Woody Biomass Co-firing Technology

Hyper-Coal based High Efficiency Combustion Technology(Hyper Coal)

Low-Rank Coal Upgrading Technology (UBC Process)

High Calorific Value Gas Production Technology

Hydrogen Production Technologyin Coal Utilization

3A1

3A2

4C1

1B1-3

3A3

3A4

3B1

3B2

3C1

3C2

3C3

3C4

3D1

3D2

5A1

Bituminous Coal Liquefaction Technology (NEDOL)

Coal Liquefaction Technology Development in Japan


Environmental �countermeasuresUtilization

Coal Center

4

Power plant

Electric precipitator EOR by CO2

Yokohama Landmark

Cement plant

Iron works Chemical plant

CO2reductionFlue gas treatment

Flue gas desulfurization unit

Flue gas denitration unit

Coal ash effective use

Flue gas treatment �technology

CO2 reduction �technology

Civil field

Architecture field

New use development

Coal ash utilization �technology

SOx Reduction Technology

NOx Reduction Technology

Soot/dust Treatment Technology and Trace Elements Removal Technology

Gas Cleaning Technology

Intra-furnace Dinitrogen Monoxide Removal Technology

Base Materials Production Technology

High Strength Artificial Aggregate Production Technology

Agriculture and Fishery Field

Dry Desulfurization Technologywhich used Coal Ash

Hydrogen Production by Reaction Integrated Novel Gasification Process (HyPr-RING)

CO2 Recovery and Sequestration Technology

CO2 Conversion Technology

Coal Ash Generation Process and Application Fields

Soil Improvement Method (FGC)

Coal fired power generation �technology

Combustion technology

Gasification technology

Iron making technology

Technology for general�industries

Pulverized Coal Fired Power Generation Technology(Ultra Super Critical Steam)

Circulating Fluidized Bed Combustion Technology (CFBC)

Internal Circulating Fluidize Bed Combustion Technology (ICFBC)

Pressurized Internal Circulating Fluidized Bed Combustion Technology (PICFBC)

Coal Partial Combustor Technology (CPC)

Pressurized Fluidized Bed CombustionTechnology (PFBC)

Advanced Pressurized Fluidized Bed Combustion Technology (A-PFBC)

Hydrogen-from-Coal Process (HYCOL)

Integrated Coal Gasification Combined Cycle (IGCC)

Coal Energy Application for Gas, Liquid and Electricity (EAGLE)

Hyper-Coal utilization High Efficiency Combustion Technology (Hyper Coal)

The Formed-Coke making Process (FCP)

Pulverized Coal Injection for Blast Furnace (PCI)

Direct Iron Ore Smelting Reduction Process (DIOS)

Super Coke Oven for Productivity and Environment Enhancement toward the 21st Century (SCOPE21)

Fluidized Bed Advanced Cement Kiln System (FAKS)

Co-generation System

Coproduction System

4B2

4B3

4B4

4B5

4B2

4A4

4C1

4C2

4C3

4C4

4A1

4A2

4A3

4A3

4A3

4A3

4A4

1A1

1A2

1A3

1A4

1A5

1A6

1A7

1B1

1B2

1B3

2A1

2A2

2A3

2A4

New Scrap Recycling Process (NSR) 2B2

2B1

6A1

6A2

3D1

1A1

1A1

Classification No. according to the technology overview

Classification No. according to the related technology overview

4B1

Combustion Technology

De-SOx and De-NOx Technology

Oxy-fuel Combustion (Oxygen-firing of conventional PCF System)

Effective use for Cement/Concrete

Valuable Resources Recovery Technologies for Coal Ash

Part1 Classification of CCT

5

Clean Coal Technologies in JapanClean Coal Technology System

Proved reserves and R/P (ratio of reserves to production) �of major energy resources

Oil

World reserves

Annual productionrate

Loca

l res

erve

s

27 billion barrel (73.9 million BD)2.5 trillion m34.83 billion ton 0.037 million ton

R/P 40.6 years60.7 years204 years 61.1 years

1,480 billion barrel156 trillion m39,845 billion ton

North America

S.& Cent. America

Europe

Former Soviet Union

Middle East

Africa

Asia Pacific

3.6%

10.6%

1.8%

7.5%

65.4%

7.4%

3.7%

4.4%

4.7%

3.8%

35.4%

36.0%

7.6%

8.1%

26.1%

2.3%

13.2%

22.9%

0.2%

5.6%

29.7%

17.9%

6.5%

3.5%

30.6%

0.0%

17.8%

23.8%

393 million ton

Natural gasCoal Uranium

Prepared from Oil, natural gas, and coal: BP Statistics 2003Uranium: OECD/NEA,IAEA URANIUM2001

South and Central America

U.S.A.

North America

Worldwide

Australia

Asia and Oceania

China

Russia

IndiaMiddle East

South Africa

Africa

Europe, FSU

Coa

lO

ilNa

tura

l gas

World reserves of coal, oil, and natural gas resources �(Unit: 100 million tons oil equivalent)

1,667

133

561934

515

11

687

82

437

556

7 7

589

2514

1,606

52116

415

4 23

5,012

1,4271,430

1,260

64 66

1,220

3848

98141

65330

0 0

368

103109

(Saurce: BP 2003)

(Degree of technology maturity)

Coal preparation

Advanced coal cleaning technology

Technology for low emission coal utilization

Integrated coal gasification combined cycle power generation technology (IGCC)

Multi-purpose coal conversion (CPX)Coal Flash Partial hydropyrolysis technology

Topping cycle.

O2/CO2

combustion

Advanced flue-gastreatment

Hot gas clean up technology

Alkaline, etc. removal technology

Wet desulfurization

Denitration

Removal of dust

Dry desulfurization/denitration

Coal Ash Utilization Technologies

Fluidized bed boilerPressurized fluidizedbed combustion (PFBC)

Fluidized bed Advanced cement Kilm System(FAKS)

Direct Iron-Ore Smelting reduction process(DIOS)

Bituminous coal liquefaction technology (NEDOL)

Brown coal liquefaction technology (BCL)

Upgrading of Coal-Derived Liquids

Coal-based hydrogen production technology (HYCOL)

Coal Energy Application for Gas,Liqud and Electricity (EAGLE)

Conventional coal preparation techniques (jig, floatation, heavy media separation)

Preparation process control technologyDiversification of energy

Sources/expansion of

application fields

Ease of handling

More efficient use of energy/

CO2 reduction

(as a measure against the

greenhouse effect)

Reduction in SOx, NOx,

and waste (as a measure

against acid rain)

(as a global environmental

measure)

Bio-briquetting

Carbonization briquetting

Coal Cartridge System (CCS)

Coal liquid mixture (CWM,COM)

Preparation

Processing

Conversion

Combustion

Pollutant reduction

(Target)(Coal flow)

Briquetting

Handling

Liquefaction

Gasification

Pyrolysis

High-efficiency combustion

Flue gas treatment

Ash utilization

Desulfurized CWM

America

Canada

Poland

ex-USSR

U.K.

Australia

China

India

Indonesia

Japan

World

6

CPX

Technological difficulty

Technical scope in which Technological and economical difficultes remain

Conventional technology development region

Technology at a practical use level

Commercialization technology

Technological difficulty

Cost reduction technology development

Overseas demonstration (International demonstration cooperated jointly)

Eco

nom

ic d

iffic

ulty

Eco

nom

ic d

iffic

ulty

USC

FBC

Cement raw material

Gypsum board

SCOPE21DIOS

Formed-coke

NSR

Briquette

Bio-coal

Wet coal preparationBrown coal dewatering

Dry coal preparation

Melting and fiber-forming

FGC melting and mixing treatment

Fluidized bed solidification material

Artificial aggregate

Ash-removed CWM

CWM

COM

CCS

Pneumatic transfer

P I C F B

I C F B

P C F B C

C F B CFlue gas

treatment

Simplified dry desulfurizationNEDOL

BCL

Gasification furnace (fluidized bed, spouted bed)

Hyper Coal Power Generation

PFBC

CCT transfer

A-PFBC

P-CPC

HyPr-RING

PCI

DME GTL

DME

IGCC

HYCOL

EAGLE

IGFC

Hyper Coal

Advanced flue

gas treatmentFAKS

Domestic coal conversion and reforming technology

Overseas coal conversion and reforming technology Overseas coal utilization technology

Domestic coal utilization technology


Coal production and consumption by country in 2002 (Total coal production in the world: 3,837 billion ton. Total coal consumption in the world: 3,853 billion ton.)�

and Coal import to Japan (Total coal import to Japan: 168.5 million ton)

(production)�

�

Others 276

Cement/ ceramics 1,296

Chemicals 575

Electric power 6,186

Pulp / paper 491

Gas / coke 412

Iron making 6,221

(Source : Coal Note 2003)

FY1970 ’75 ’80 ’95’85 ’90 ’01’00 ’02

(consumption)

Hyper Coal

Coal Ash utilization

896917

30 20

103 81

Germany

29 60

164140

30 58

223156 276

78

1,3261,252

334 357

10128

0163

3,837 3,853

9.6(5.7%)

0.4(0.2%)

91.8(54.5%)

19.6(11.6%

)

0.4(0.3%)

33.5(19.9%)

15,45715,236

13,057

11,54811,145

9,394

8,225

9,079

16,317

Source:IEA COAL INFORMATION 2003Coal Yearbook 2003

Trend of coal demand in Japan�(Unit: 10 thousand tons)�

�

Ste

am c

oal

Cok

ing

coal

Appreciation of CCT in Markets

Part1 Classification of CCTClean Coal Technologies in Japan

7 8

Power generation field

Location of coal fired power plants��

Coal fired power generation technology

Iron making field

Location of iron works

Iron making technology

Coal

Coking coal

Pig iron

SlagSCOPE21

Formed-coke furnace

Converter

Electric furnace

NSR

PCI

Blast furnace

DIOS

Steamcoal

Coal

Numerals in parentheses designate power generate capacity (10 thousand kW) at the end of FY2001.

Numerals in parentheses designate produced crude steel (MT) as of FY2002.

Steam coal

Pulverized coal

Combustion

furnace

boiler

Steam

turbine

The Formed-Coke making Process (FCP)

New Scrap Recycling Process (NSR)

Pulverized Coal Injection for Blast Furnace (PCI)

Direct Iron Ore Smelting Reduction Process (DIOS)

Super Coke Oven for Productivity and Environment Enhancement toward the 21st Century (SCOPE21)

Iron and steel

Hydrogen-from-Coal Process (HYCOL)

Integrated Coal Gasification Combined Cycle (IGCC)

Gas Cleaning Technology

Coal Energy Application for Gas, Liquid and Electricity (EAGLE)

Hyper-Coal based High Efficiency Combustion Technology (Hyper Coal)

Gas cleaning

Wastewater

Gas

turbine

Coal

gasification

furnace

Generator

1B1

4B5

1B2

1B3

3D1

2A2 2A1

2A4 2A3

2B2

Sunagawa(25)Naie(35)Tomatou Atsuma(103.5)

Ishikawa(31.2)

Gushikawa(31.2)

Kin(22)

Sendai(52.5)

Sumitomo Metal (Kashima)(6,820,450)

Nippon Steel (Kimitsu)(9,195,689)

JFE Steel (Chiba)(4,186,020)

Shinchi(200)Haramachi(200)Hirono (under construction)Nakoso(145)

Hitachi Naka (100)

Isogo (120)

Hekinan(310)

Tachibanawan(210+70)

Saijo(40.6)

Sumitomo Metal (Wakayama)(3,412,887)

Nippon Steel (Nagoya)(5,651,300)

JFE Steel (Keihin)(3,472,723)

Nippon Steel (Oita)(8,012,585)

Noshiro(120)

Nanao Ota(120)Toyama Shinko Kyodo(50)

Tsuruga(120)Maizuru (under construction)

Takasago(50)Mizushima(28.1) JFE Steel (Mizushima)(8,423,478)

Kobe Steel (Kakogawa)(5,397,267)

JFE Steel (Fukuyama)(9,885,534)

Kobe Steel (Kobe)(1,062,063)

Osaki(25)Takehara(130)

Misumi(100)

Shin-onoda(100)Shimonoseki(17.5)

Kanda(36)

Nippon Steel (Yawata)(3,514,941)

Minato(15.6)Matsuura(270)

Omura(15.6)Matsushima(100)

Reihoku(70)

Sakata(70)

Pulverized Coal Fired Power Generation Technology(Ultra Super Critical Steam)

Circulating Fluidized Bed Combustion Technology (CFBC) Coal Partial Combustor Technology (CPC)

Pressurized Fluidized Bed CombustionTechnology (PFBC)

Advanced Pressurized Fluidized Bed Combustion Technology (A-PFBC)

1A1

1A2

1A3

1A4

1A5

1A6

1A7

Internal Circulating Fluidize Bed Combustion Technology (ICFBC)

Pressurized Internal Circulating Fluidized Bed Combustion Technology (PICFBC)

Stack

Electric power

1990 ’91 ’92 ’93 ’94 ’95 ’96 ’97 ’98 ’99 ’00 ’02’01

180

160

140

120

100

80

60

40

20

0

1800

1600

1400

1200

1000

800

600

400

200

0 1990 ’91 ’92 ’93 ’94 ’95 ’96 ’97 ’98 ’99 ’00 ’01 ’02

180

160

140

120

100

80

60

40

20

0

180

160

140

120

100

80

60

40

20

0

Coa

l con

sum

ptio

n (m

illio

n to

n)

Cru

de s

teel

pro

duct

ion

(mill

ion

ton)

Coal consumption in iron making sector and crude steel production

Coal consumption

Crude steel production

Coal consumption in power generation sector and generated power

Coa

l con

sum

ptio

n (m

illio

n to

n)

Gen

erat

ed p

ower

(G

kWh)

Generated power

Domestic total coal consumptionDomestic total coal consumption

Coal consumption

CCT in Japanese Industries

Part1 Classification of CCTClean Coal Technologies in JapanCCT in Japanese Industries

9 10

Cement production field

Location of cement plants

Cement production technology

Coal chemicals and other fields

Location of chemicals complexes

Coal chemicals process

Numerals in parentheses designate clinker production capacity (1000 t/y) as of April 1, 2003.

Numerals in parentheses designate ethylene production capacity (1000 t/y) at the end of FY2002.

Numerals in parentheses designate the percentage of coal in primary energy.

Coal energy supply, GDP, and CO2 emissions in Japan

1990 ’91 ’92 ’93 ’94 ’95 ’96 ’97 ’98 ’99 ’00 ’01 ’02

Coa

l ene

rgy

supp

ly (

PJ)

GD

P (

trill

ion

yen)

GDP

540

520

500

480

460

440

420

400

380

360

4,600

4,400

4,200

4,000

3,800

3,600

3,400

3,200

3,000

2,800

(16.5)(16.9) (16.1) (16.0)

(16.3)(16.5) (16.4) (16.7) (16.3) (17.2)

(17.8)(17.8)(17.8)

(19.0)(19.0)

(19.5)(19.5)

291.4 286.1294.5 291.0

307.1307.1309.1

316.0 318.6

303.3

311.4317.3

307.4

316.7316.0 318.6 317.3 316.7

(16.3)(16.3)

CO2 emissions (Mt-C)

Coal energy supply

303.3

1990 ’91 ’92 ’93 ’94 ’95 ’96 ’97 ’98 ’99 ’00 ’01 ’02

180

160

140

120

100

80

60

40

20

0

180

160

140

120

100

80

60

40

20

0

Coa

l con

sum

ptio

n (m

illio

n to

n)

Cem

ent p

rodu

ctio

n (m

illio

n to

n)

Coal consumption in cement production sector and cement production

Cement production

Domestic total coal consumption

Coal consumption

Ryukyu Cement (Yabu)(722)

Ryukyu Cement (Yabu)(722)

Nittetsu Cement (Muroran)(968)

Taiheiyo Cement (Kamiiso)(3,944)Mitsubishi Material (Aomori)(1,516)

Hachinohe Cement (Hachinohe)(1,457)

Taiheiyo Cement (Ofunato)(2,680)

Mitsubishi Material (Iwate)(670)

Sumitomo Osaka Cement (Tochigi)(1,489)

Hitachi Cement (Hitachi)(848)

Mitsubishi Chemical (Kashima)(828)

Mitsui Chemicals (Ichihara)(553)Idemitsu Petrochemical (Chiba)(374)Sumitomo Chemical (Anegasaki, Sodegaura)(380)

Maruzen Petrochemical (Goi)(480)Keihin Ethylene(690)

Chichibu Taiheiyo Cement (Chichibu)(800)Taiheiyo Cement (Kumagaya)(2,267)Mitsubishi Material (Yokoze)(1,213)Taiheiyo Cement (Saitama)(1,655)

Nippon Petrochemicals (Kawasaki)(404)

Tonen Chemical (Kawasaki)(478)

DC (Kawasaki)(1,108)

Taiheiyo Cement (Fujiwara)(2,407)

Mitsubishi Chemical (Yokkaichi)

Tosoh (Yokkaichi)(493)

Taiheiyo Cement (Tosa)(1,165)

Taiheiyo Cement (Kochi)(4,335)

Taiheiyo Cement (Tsukumi)(4,598)Taiheiyo Cement (Saeki)(1,426)

Myojo Cement (Itoigawa)(2,108)Denki Kagaku Kogyo (Omi)(2,703)

Tsuruga Cement (Tsuruga)(816)

Sumitomo Osaka Cement (Gifu)(1,592)

Tosoh (2,606)Tokuyama (Nanyo)(5,497)

Idemitsu Petrochemical (Suo)(623)

Mitsui Chemicals (Iwakuni-otake)(623)

Mitsubishi Chemical (Mizushima)(450)

Sanyo Petrochemical (443)

Ube Industries (1,612)Ube Industries (4,872)

Nippon Steel Blast Furnace Cement (Tobata)(808)Mitsubishi Materials (Kyushu)(8,039)

Ube Industries (Kanda)(3,447)Kanda Cement (Kanda)(1,085)

Kawara Taiheiyo Cement (Kawara)(800)Mitsui Mining (Tagawa)(1,977)Aso Cement (Tagawa)(1,412)

Mitsui Chemicals (Osaka)Osaka Petrochemical (455)

Showa Denko (Oita)(581)

Recycle raw material

Limestone

Clay

Iron raw material

Drier

Air separator

Air separator

Cement cooler

Cement silo

Track

Tanker

Coal

Coal mill

Heavy oil tank

Electric precipitator

Electric precipitator

Silo

Preheater

Clinker silo

Pre-pulverizing mill

Rotary kiln Clinker

cooler

Raw material mill

Fluidized Bed Advanced Cement Kiln System (FAKS)

<Technology for Effective Utilization of Coal Ash>Effective use for Cement/Concrete

Gypsum

Coal

(Raw material charge process)

(Coal conversion process)

(Fractionation process)

(Recycle)

Medium distillate

Heavy distillate

Vent

(Separation, purification process)

Residue coal

Water

Air

Wastewater

High value-added product

4A2

2B1

Asahi Kasei (Mizushima)

Multi-Purpose Coal Conversion Technology (CPX)

Coal Flash Partial Hydropyrolysis Technology

3B1

3B2Low-Rank Coal Upgrading Technology (UBC Process)3D2

Hyper-Coal based High Efficiency Combustion Technology(Hyper Coal) 3D1

BTX and mono- and di-cyclic components

Brown Coal Liquefaction Technology (BCL)

Dimethylether Production Technology (DME)

4C1

3A1

3A2

3A3

3A4

Bituminous Coal Liquefaction Technology (NEDOL)

Coal Liquefaction Technology Development in Japan

Hydrogen Production by Reaction Integrated Novel Gasification Process (HyPr-RING)

Electrode

DC high voltage

Flue gas (from boiler)

NH3

(Ammonia)

Flue gas

Gypsum Gypsum

Mechanism of flue gas denitration unit

Mechanism of flue gas desulfurization unit

Mechanism of electrostatic precipitator

Clean gas (to stack)

Mixed liquor of limestone and water

Pump

Pump

Discharge electrodeCollected

coal ashCollecting electrode

NOX

NH3

Catalyst

N2

H2O

NOX

NOX

NOXNOX

NOX

NOX

NOX

NH3NH3

NH3

N2

N2

N2H2O

H2O

H2O

CO2 emissions in major countries (million ton as carbon)

USA

Canada

UK

France

Germany

Italy

ex-USSR

China

India

Japan

World total

Unit

Mt-C

%

Mt-C

Mt-C

Mt-C

Mt-C

Mt-C

Mt-C

%

Mt-C

%

Mt-C

Mt-C

%

Mt-C

1,352

23.0

129

164

102

271

113

1,036

17.6

617

10.5

153

269

4.6

5,872

1,578

26.9

158

151

109

226

121

638

10.9

780

13.3

249

310

4.8

6,417

1,559

26.5

155

153

108

223

121

654

11.1

832

14.2

250

316

4.8

6,522

1,624

27.7

172

155

106

224

124

780

13.3

888

15.1

272

319

4.6

6,908

1,800

30.7

186

163

108

232

129

825

14.0

1,109

18.9

321

334

4.3

7,685

2,082

35.5

196

176

122

241

140

939

16.0

1,574

26.8

435

365

3.9

9,372

1990 2000 2001 2005 2010 2020

Part1 Classification of CCTEnvironmental Technologies Clean Coal Technologies in Japan

11

Emission reduction technology to remove dust, sulfur oxides,

and nitrogen oxides is developed by treating and combusting

flue gas from coal combustion through superior process design.

Flue gas treatment technology

Electrostatic Precipitator�Flue gas passes between two electrodes that are charged by a high voltage current. The ash and dust are negatively charged, and are attracted toward and deposit on the cathode. The ash and dust deposited on the cathode where periodical hammering occurs are collected in the lower section of the electrostatic precipitator and subsequently removed. The principle is the same with the phenomenon that paper and dust adhere to a celluloid board electrostatically charged by friction.Flue Gas Desulfurizer�Limestone is powdered to prepare a water-based mixture (limestone slurry). The mixture is sprayed into the flue gas to induce a reaction between the limestone and the sulfur oxides in the flue gas to form calcium sulfite, which is further reacted with oxygen to form gypsum. The gypsum is then separated as a product.Flue Gas Denitrizer�Ammonia is added to the flue gas containing nitrogen oxides. The mixture gas is introduced to a metallic catalyst (a substance to induce chemical reactions). The nitrogen oxides in the flue gas undergo catalyst-induced chemical reactions to decompose into nitrogen and water.

Reaction formulae

Cement raw material 5,694 73.7%

Cement field78.7%Civil field 8.8%

Architecture field 4.9%

Agriculture, forestry, and fishery fields 1.8%

Other 5.8%

Concrete admixture 147 1.9%Cement admixture 239 3.1%

Building material board 347 4.5%

Other building materials 29 0.4%

Fertilizer, soil improving material, etc. 139 1.8% Other

446 5.8%

Total 7,724(thousand ton)

Power in Japan: Effective use of coal ash generated from general industries, (FY2002)(Source: Center for Coal Utilization, Japan)

Coal mine filler188 2.4%

Road and base materials115 1.5%

Ground improving material 246 3.2%

Civil work material, etc. 134 1.7%

(Ammonia)4NO + 4NH3 + O2 4N2 + 6H2O

6NO2 + 8NH3 7N2 + 12H2O(Nitrogen gas)

Ash generated during coal combustion is effectively

used as raw material for cement and other applications.

Effective coal ash utilization in Japan

CO2 emissions in Japan

1)Flue gas treatment technology 2)Coal ash effective use technology

3)Global warming countermeasures technology (Technology to reduce CO2 emissions)

4)Environmental Protection and fuel conversion technology

(DME, GTL)

(Nitrogen monoxide)

(Nitrogen gas)

(Nitrogen dioxide)

Energy conversion sector (power plant, etc.)6.9% (direct incineration: 30.9%)

Industry sector 40.0% (direct incineration: 31.0%)

Commercial sector (Household)13.5% (direct incineration: 6.0%)

Commercial sector (Business)12.3% (direct incineration: 5.2%)

3 Transportation sector (automobile, ship, and aircraft)20.7% (direct incineration: 20.2%)

Industrial process (limestone consumption)4.3% (direct incineration: 4.3%)

Waste (plastics and waste oil incineration)2.0% (direct incineration: 2.0%)

Other (non-fuel sector, etc.)2.0% (direct incineration: 2.0%)

CO2 emissions in Japan for individual sectors(Source: Headquarters of Countermeasures to Global Warming (FY2000))

Source; The Federation of Electric Power Companies of Japan

(Source: IEO 2004)

Energy-related sectors (93.7%)

America(1999)

CanadaUK(1999)

France(1998)

Germany(1999)

Italy(1999)

Japan(2002)

Emissions of SOx and NOx per generated power in major countries

(Thermal power plant)

SOx

NOx

9

8

7

6

5

4

3

2

1

0

(g/kWh)

7.1

3.03.2

1.4

4.8

2.1

2.7

4.0

2.0

1.20.7

0.20 0.26

0.9

Part1 Classification of CCTInternational Cooperation Clean Coal Technologies in Japan

12

Current state of international cooperation

Concomitant with the progress of industrialization and

urbanization, developing countries face serious air and water

pollution issues. Particularly in Asia and Oceania, the percentage

of coal in the energy mix is large and sustainable economic

development further emphasizes the importance of the

development and widespread dissemination of coal utilization

technology with full-scale environmental conservation measures.

Since developing countries do not have sufficient capital,

technology, and human resources for such technology, self-help

efforts are limited, and the assistance of developed countries

including Japan and of international organizations is requested.

Japan has promoted international cooperation in terms of

"pollution countermeasure technology" to reduce emissions of

SOx, NOx, and dust, and of "high efficiency power generation

technology" to improve energy use efficiency with a focus on the

Green Aid Plan (GAP) counterpart countries of China, Indonesia,

Thailand, Malaysia, the Philippines, India, and Vietnam.

From GAP to CDM

In recent years, the global warming issue has attracted intense

international concern. Global warming is a serious problem for

the future of the earth and humankind, and is closely related to

human economic activity and the accompanying energy

consumption. Thus, satisfying both "economic development" and

"the environment" becomes an important issue.

The Kyoto Protocol, adopted at Kyoto in December 1997 and

ratified by Japan in June 2002, includes the "Kyoto Mechanisms",

an important instrument of international cooperation. In particular,

the Kyoto Mechanisms include a market mechanism called the

Clean Development Mechanism (CDM), which is a forthcoming

system that aims to reduce greenhouse gases through

cooperation between developed and developing countries.

From the viewpoint of overcoming global environmental issues

that continue to spread worldwide, developing countries are

requested to maximize their self-help efforts toward improvement

of the environment in order to prevent ever-increasing pollution

and global warming.

Japan is requested to contribute to the economic growth and

environmental improvement of developing countries through the

active introduction of Japanese Clean Coal Technology (CCT)

into Asian countries such as China, which are expected to show

continued increases in coal consumption.

1)Pollution countermeasures technology(SOx, NOx, and dust/soot reduction technology)

2)High efficiency power generation technology(IGCC, IGFC)

3)CO2 emissions reduction technology(CDM, JI countermeasures technology)

List of clean coal technologies and model projects relating to GAP

Project name Project period Target country Site Counterpart

Cleaning after combustion

Simplified

desulfurization unit

Coke oven gas desulfurization unit

FY1993-FY1995

FY1995-FY1997

FY1998-FY2001

FY1999-FY2002

People’s Republic of China

Thailand



Cleaning during combustion, improvement of combustion efficiency


Philippines


Indonesia



Thailand


FY1993-FY1995

FY1995-FY1997

FY1996-FY1998

FY1996-FY1999

FY1997-FY1999

FY1997-FY2001

Circulating fluidized

bed boiler

Cleaning before combustion


Indonesia

Indonesia

Thailand

Philippines



FY1993-FY1995

FY1996-FY1998

FY1997-FY1999

FY1998-FY2002

FY1994-FY1997

FY1995-FY1998

Briquette production

unit

Water-saving coal

preparation system

Desulfurization type CWM unit

Electricity Generating Authority ofThailand (Lampang)

Coal Fired Power Generation Technologies (Combustion Technologies)

13�

1A1. Pulverized Coal Fired Power Generation Technology (Ultra Super Critical Steam)Outline of technology

1.Efficiency increase�

Increase in the thermal efficiency of power generation plant is an

important issue in terms not only of economy to decrease the

power generation cost but also of suppression of CO2 emissions.

In particular, coal fired power plants which are the main stream of

current large thermal power plants increase their steam

temperature level. The right figure summarizes the trend of steam

conditions in recent years.

In 1989, Kawagoe No.1 plant (700 MW) of Chubu Electric Power

Co., Inc. adopted steam condition of 316 kg/cm2G (31.0 MPa) x

566OC/566OC/566OC. In 1993, Hekinan No.3 plant (700 MW) of

the company adopted the steam condition of 246 kg/cm2G (24.1

MPa) x 538OC/593OC, which 593OC was the first highest

temperature of reheated steam in Japan. After that, Misumi No.1

plant (1000 MW) of The Chugoku Electric Power Co., Inc. and

Haramachi No.2 plant (1000 MW) of Tohoku Electric Power Co.,

Inc. adopted the steam condition of 24.5 MPa x 600OC/600OC in

1998. Furthermore, Tachinbanawan No.1 and No.2 plant (1050

MW) of Electric Power Development Co., Ltd. adopted the steam

condition of 25.0 MPa x 600OC/610OC in 2000. The figure below

shows an example of relation between the steam condition and

the increase in efficiency at a supercritical pressure plant.

Responding to the movement of increase in the steam

temperature, power companies, steel manufacturers, and boiler

manufacturers promote the development and practical

application of high strength materials having superior high

temperature corrosion resistance, steam-oxidation resistance,

and workability. The high-temperature materials for 650OC level

use have already been in the practical application stage, and the

study proceeds to satisfy 700OC level use aiming at further high

efficiency of the thermal plants. The figure below shows the

steam conditions and the high temperature materials for the

respective steam conditions.

2.25Cr 1Mo

18 Cr

2.25Cr 1Mo

9 Cr

9 Cr 12 Cr 18 Cr

20-25 Cr

9 Cr 12 Cr 18 Cr

538 566 593 621 649Steam temperature (OC)

200

300 10

0

1910 1920 1930 1940 1950 1960 1970 19901980 2000

20

Steam pressure (Right scale)

Steam temperature (Left scale)

16.6MPa

30

400

500

600538OC

Ste

am te

mpe

ratu

re O

C

Ste

am p

ress

ure

MP

a

600OC

593OC566OC

610OC

24.1MPa

24.5MPa31.0MPa

5

4

3

2

1

0

Effi

cien

cy in

crea

se r

ate

(%)

Temperature of main steam (OC)

Temperature of reheated steam (OC)

538 538 566 600 625

566

(Base)

593 593 600 625

18 Cr 20-25 Cr

: Ferritic Material : Austenitic Material

Main steam pipe

Superheater tube

Hot reheat pipe

Reheater tube

Fig. 1 Changes in steam condition with time

Fig. 2 Relation between the steam condition and the efficiency improvement at supercritical pressure plants

Fig. 3 Steam conditions and high temperature materials

Part2 Outline of CCT

Fig.7 Pulverized coal fired NR burner: Babcock-Hitachi K.K.


14

Fig.8 Conceptual drawing of intrafurnace denitration

Fig.4 Pulverized coal fired A-PM burner: Mitsubishi Heavy Industries, Ltd.

Fig.5 CC type pulverized coal fired burner: Kawasaki Heavy Industries, Ltd.

Fig.6 DF intervene pulverized coal fired burner: Ishikawajima-Harima Heavy Industries Co., Ltd.

2.Combustion technology�

Various combustion technologies have been developed and

practically applied responding to the need to satisfy current

severe environmental regulations and to respond to the high

efficiency combustion. The emission level of NOx and dust

generated during the combustion of coal is the world’s lowest

level even at boiler exit, though the ultimate emission level owes

the flue gas treatment given at downstream side of the boiler.

Since emission of NOx and that of dust are very closely related to

each other, this paper focuses on the low NOx combustion

technology. The low NOx combustion technology is roughly

grouped to the suppression of NOx generation at burner and the

intrafurnace denitration using the whole zones in the furnace.

(1) Low NOx combustion at coal burner

Although the structure of burner differs between large-boiler

manufacturers, the most advanced burners basically adopt the

separation of dense and lean pulverized coal streams and the

multilayer charge of combustion air aiming to attain the ignitability

increase and to conduct the intraflame denitration. Figures 4 to 7

show the burner structure of several manufacturers.

(2) Intrafurnace denitration

Intrafurnace denitration is conducted by reducing the NOX

generated in the main burner zone using the residual

hydrocarbons or the hydrocarbons generated from small amount

of fuel oil charged from the top of the main burner. The

intrafurnace denitration is performed in two stages. Figure 3 is

the conceptual drawing of the intrafurnace denitration.

In the first stage, hydrocarbons reduce NOx. In the second

stage, the unburned matter is completely combusted by the

additionally charged air.

Denseflame

Leanflame

Dense flame

Lean flame

Dense flame

Dense flame

Lean flame

Dense flame

Enhancing intraflame denitration combustion by the outer periphery stable ignition

Secondary air

Secondary air

Tertiary airTertiary air

Tertiary air swirling vane

Distributor vane

Oil burner

Primary air + Pulverized coal

Secondary throatPrimary throat

Rib

Primary flame holding plate

Secondary flame holding plate

Reducing flame

Primary air + Pulverized coal

Tertiary air damper

Oil burnerPrimary air + Pulverized coal

Tertiary air

Burner inner cylinder

Burner outer cylinder

Secondary air inner vaneSecondary air vane

Flow detectorThroat ring

Oil burner support

Secondary air vane driver

Secondary air inner vane driverSecondary air Inner secondary air

Outer secondary air

Furnace wall tube

Primary air (Pulverized coal + Air)

Inner periphery secondary air

Outer periphery secondary air

Volatile matter combustion zone

Reducing agent generation zone

NOx decomposition zone

Char combustion enhancing zone

Furnace exit

Combustion completion zone

NOx reducing zone containing unburned fuel

Main burner combustion zone

Main burner

Aditional Air

Over Fire Air


15

1A2. Circulating Fluidized Bed Combustion Technology (CFBC)Outline of technology

1.Features�

The features of circulating fluidized bed boiler are described

below.

1)Wide range of fuel adaptability

Conventional boilers for power generation can use only fossil fuel

such as high grade coal, oil, and gas. The CFBC also uses low

grade coal, biomass, sludge, waste plastics, and waste tire as fuel.

2)Low pollution

Emissions of pollutants such as NOx and SOx are significantly

decreased without adding special environment measures. For

the case of fluidized bed boiler, the desulfurization is intrafurnace

desulfurization using mainly limestone as the fluidizing material.

For the denitration, ordinary boilers operate at combustion

temperatures from 1,400OC to 1,500OC, and the circulating

fluidized bed boiler operates at lower temperatures ranging from

850OC to 900OC so that the thermal NOx emissions (generated

NOx depending on temperature) are suppressed. In addition, the

operation of circulating fluidized bed boiler is conducted by two-

stage combustion: the reducing combustion at the fluidized bed

section; and the oxidizing combustion at the freeboard section.

Then, the unburnt carbon is collected by a high temperature

cyclone located at exit of the boiler to recycle to the boiler, thus

increasing the denitration efficiency.

3)High combustion efficiency

High combustion efficiency is attained by excellent combustion

mechanism of circulating fluidization mode.

4)Space saving and high maintenance ability

Space saving is attained because there is no need of separate

desulfurization unit, denitration unit, and fuel finely crashing unit.

Accordingly, sections of trouble occurrence become few, and

maintenance becomes easy.

4.Study period�

Most of the technologies of circulating normal pressure fluidized

bed boiler (CFBC) are introduced into Japan from abroad

beginning from around 1986.

5.Progress and result of the development�

The CFBC was introduced from abroad as the coal fired boiler,

and is used in power companies, iron making companies, paper

making companies, and other sectors. The CFBC is planned to

distribute in China under the Green Aid Plan (GAP). The issues

of CFBC include further investigations of and efforts for initial cost

and power generation efficiency in the boilers using fuel such as

RDF, industrial waste, and wood-base biomass.

2.Outline of technology�

Figure 1 shows a typical process flow of CFBC

Figure 2 shows rough structure of CFBC. Generally CFBC is

structured by the boiler and the high temperature cyclone. The

intrafurnace gas velocity is as high as 4 to 8 m/s. Coarse fluidizing

medium and char in the flue gas are collected by the high

temperature cyclone, and are recycled to the boiler. The recycle

maintains the bed height and increases the denitration efficiency. To

increase the thermal efficiency, a preheater for fluidizing air and

combustion air, and a boiler feed water heater are installed. Most of

the boiler technologies are introduced from abroad: mainly from

Foster Wheeler, Lurgi, Steinmuller, ALSTOM, and Babcock & Wilcox.

Fig.2 Schematic drawing of CFBC structure

Fig.1 Process flow of circulating fluidized bed boiler

3.Study site and application field�

Photograph 1 shows overview of the CFBC boiler facilities. The CFBC

became popular mainly as coal fired boilers. Recently, however, CFBC

using RDF and wood-base biomass as the fuel has drawn attention.

Typical applications of coal fired biogas are Tamashima plant (70 t/h) of

Kuraray Co., Ltd, Chiba worksoil refinery (300 t/h) of Idemitsu Kosan

Co., Ltd., and Isa plant (210 t/h) of Ube

Industries, Ltd. Example of RDF fired boiler is

Tomakomai plant of Sanix Inc. As for the

biomass fuel, mixed combustion with coal is

adopted for decrease of CO2 emission.

Generated steam

CycloneCirculatingfluidized

bed furnace

Boiler feed water

ID fan

Ash storage tank

Stack

Flue gas

Secondary airPrimary air

Heatrecoverysection

Electricprecipitator

LimestoneCoal

CFBC boiler bodyHot cyclone

Boiler feed water heater

Air preheater

Photo 1 CFBC appearance



16

Fig. 1 Outline of ICFBC

1A3. Internal Circulating Fluidize Bed Combustion Technology (ICFBC)

Outline of technology

1.Features�

The ICFBC has basic functions described below.

I.Uniform temperature in fluidize bed owing to the swirling flow of

sand.

II.Easy discharge of noncombustible owing to vigorous

movement of sand.

III.Available in controlling the temperature of fluidized bed by

adjusting the heat recovery from fluidized bed.

Based on the basic functions, ICFBC has features described

below.

1)Adoption of various fuels

Similar with CFBC described before, the applicable fuel for

ICFBC includes not only fossil fuel such as high grade coal, oil,

and gas, but also low grade coal, biomass, sludge, waste

plastics, and waste tire.

2)Control of bed temperature

Since the overall heat transfer coefficient varies almost linearly

with the variations in air flow rate in the heat recovery chamber,

the quantity of recovering heat is easily controlled through the

control of air flow rate. In addition, control of the quantity of

recovering heat controls the temperature of fluidized bed. Since

the control of recovering heat is performed solely by varying the

air flow rate, the load control is very simple, which is a

strongpoint of ICFBC.

3)Low pollution

The emissions of pollutants such as NOx and SOx are

significantly reduced without adding special environmental

material. For the fluidizing bed boiler, the desulfurization

proceeds mainly in the furnace. However, ICFBC does not have

heat transfer tube in the fluidizing section so that the boiler raises

no wear problem on the heat transfer tube in bed. Thus, the

fluidizing material of ICFBC does not need to use soft limestone,

and it can use silica sand. As a result, ICFBC needs minimum

quantity of limestone as the intrafurnace desulfurization agent.

The desulfurization efficiency of ICFBC becomes close to 90% at

Ca/S molar ratio of around 2, though the efficiency depends on

the coal grade, applied limestone, and temperature of fluidized

bed. The denitration is conducted by two-stage combustion: the

reducing combustion at the fluidized bed section; and the

oxidizing combustion at the freeboard section. The unburnt

carbon coming from the boiler is collected by the high

temperature cyclone installed at exit of the boiler, which collected

unburnt carbon is recycled to the boiler to increase the

denitration efficiency.

4)Space saving and maintenance ability

Similar with the above-described CFBC, the ICFBC does not

need separate units for desulfurization, denitration, and fuel finely

crushing, therefore, the ICFBC facilities are space saving one

and have high maintenance ability owing to the fewer sections of

trouble-occurrence.


Figure 1 shows outline of ICFBC. The technology uses silica

sand as the fluidizing material. The fluidized bed is divided into

the main combustion chamber and the heat recovery chamber by

a tilted partition to create swirling flow inside the main

combustion chamber and the circulation flow between the main

combustion chamber and the heat recovery chamber. A

circulation flow is created to return the unburnt char and

unreacted limestone coming from the cyclone at exit of the boiler

to the boiler.

1)The swirling flow in the main combustion chamber is created by

dividing the window box in the main combustion chamber to three

sections, and by forming a weak fluidized bed (moving bed) at

the center section introducing small amount of air, while forming

rigorous fluidized bed at both end-sections introducing large

amount of air. As a result, the center section of the main

combustion chamber forms a slow downward moving bed, and

the fluidizing material which is vigorously blown up from both

ends sediments at the center section, and then ascends at both

end-sections, thus creating the swirling flow.

In charge of research and development: Center for Coal Utilization, Japan; Ebara Corporation;Idemitsu Kosan Co., Ltd.Project type: Coal Production and Utilization Technology Promotion GrantPeriod: 1987-1993

Primary �combustion �

chamber

Heat �recovery �chamber

Freeboard


17

4.Development period�

The ICFBC was developed in 1987, and was further

developed and validated as the low pollution, small scale, and

high efficiency fluidized bed boiler for multiple coal grades in

the "Study of Fluidized Bed Combustion Technology" of the

Coal Utilization Technology Promotion Grant project of the

Ministry of the International Trade and Industry over six years

from 1988 to 1993.


Although ICFBC was developed initially to use industrial waste

giving high calorific value, it was improved to use solid fuel with a

high calorlfic value and has been developed as a coal-fired boiler.

For China having abundant coal reserves, a boiler plant was

constructed at Chingtao as the production base in China.

Recently in Japan, wood-base biomass is used as the fuel in

some cases. However, further reduction in investment is

required to propagate the technology to Southeast Asia and other

areas rich in the biomass resource and low grade coal.

Photo 1 Overview of ICFBC

3.Study site and use field�

Examples of coal fired ICFBC include: Chingtao, EBARA CORP.

(10 t/h); Jiangsan in China (35 t/h); and Nakoso, Nippon Paper

Industries Co. (104 t/h). Examples of ICFBC using industrial

waste as the fuel include: Motomachi, Toyota Motor Corp. (70

t/h); Tochigi, Bridgestone Corp. (27 t/h); Fuji, Daishowa Paper

Mfg. Co., Ltd. (62 t/h); Amaki, Bridgestone Corp. (7.2 t/h); and

Akita, Tohoku Paper Mfg. Co., Ltd. (61.6 t/h). An example of RDF

fuel ICFBC is Shizuoka, Chugai Pharmaceutical Co., Ltd. (3.7

t/h).

2)The circulation flow between the main combustion chamber

and the heat recovery chamber is created by the movement

described below. A portion of the fluidizing material which is

vigorously blown up at both end-sections in the main combustion

chamber turns the flow direction toward the heat recovery

chamber at above the tilted partition. The heat recovery chamber

forms mild fluidized bed (downward moving bed) by the

circulation bed air injected from under the chamber. Accordingly,

the fluidizing material circulates from the main combustion

chamber to the heat recovery chamber, and again to the main

combustion chamber from the lower part of the heat recovery

chamber. Since the heat recovery chamber is equipped with heat

transfer tubes, the circulation flow recovers the thermal energy in

the main combustion chamber.

3)The circulation flow coming from the cyclone at exit of the boiler

passes through the cyclone or other means to collect unburnt

char, emitted fluidizing material, and unreacted limestone, and

then returns to the main combustion chamber or the heat

recovery chamber using screw conveyer, pneumatic conveyer, or

other means. The circulation flow is extremely effective to

increase combustion efficiency, to decrease NOx generation, and

to increase desulfurization efficiency.

Fig. 2 Flowchart of PICFBC hot model test plant

Dry Coal

Steam

Ash

Steam

Waste HeatBoiler(Gas Cooier)

IDF

Stack

Hot gasFilter

AirHeater

BagFilter

DepressurizingUnit

Dry FeedSystem

DeashingSystem

Pneumatic Ash Transport System

BoilerDrum

PIC

FB

Slurry FeedSystem

CWP Pump

Boiler WaterCirculationPump

Ash CoolingPipe

Air Compressor Pressure Vessel

Hot Blast Generator

Limestone

Pulverized Coal

CoalBunker

CWPMixingSystem

Crusher



18

6.Progress and issue of the study�As the coal fired PICFBC, the study proceeded up to the hot

model test at Sodegaura. The technology, however, has

developed to the pressurized two-stage gasification technology in

which the thermal load and the lock hopper system in the

pressurized fluidized bed are applied.

The issues of pressurized system include the improvement in the

reliability of lock hopper system in the fuel charge line and the

measures to low temperature corrosion.

3.Outline of technology�Figure 1 shows schematic drawing of

PICFBC. The cylindrical pressure vessel

contains the cylindrical ICFBC. Similar

with ICFBC, silica sand is used as the

fluidizing material. The fluidized bed is

divided into the main combustion

chamber and the heat recovery chamber

by the tilted partition. The swirling flow

is created in the main combustion

chamber, and the circulation flow is

created between the main combustion

chamber and the heat recovery chamber.

Figure 2 (P.17) shows the rough flowchart of the hot model test plant

at Sodegaura. The coal feed unit has two lines: the lock hopper

system which feeds lump coal ; and the CWP(Coal Water Pellet)

mixing system which feeds coal as slurry mixed with water. The

dust of combustion gas is removed by the high temperature bag

filter structured by ceramics filter. The lock hopper system

technology is applied to develop the pressurized two-stage

gasification technology.

Fig. 1 Schematic drawing of PICFBC


1.Outline�The basic technology is the technology of internal circulating

fluidized bed boiler (ICFBC) described in preceding section. The PICFBC mounts ICFBC in a pressure vessel.

1A4. Pressurized Internal Circulating Fluidized Bed Combustion Technology (PICFBC)

5.Period of development�The PICFBC hot model test was carried out from 1992 to 1997. The hot

model test was conducted jointly with The Center for Coal Utilization,Japan,

as the Coal Utilization Technology Promotion Grant project of the Ministry of

International Trade and Industry. The test operation began from December

1996. The pressurized two-stage gasification technology was developed

jointly with Ube Industries, Ltd. The demonstration operation of the plant

(30 t/d of waste plastics throughput) began from January 2000, and the

commercial operation began from January 2001.

4.Study site and use field�The PICFBC hot model test was carried out at a site next to the

Coal Research Laboratory (Nakasode, Sodegaura City, Chiba) of

Idemitsu Kosan Co., Ltd. Applicable fields include the steam

turbine generator using the generated steam and the gas turbine

generator using the combustion flue gas. Therefore, IGCC at coal

fired thermal power plant is a candidate. Photograph 1 shows the

installed hot model of PICFB 4 MWth. Photograph 2 shows the

overview of the pressurized two-stage gasification plant (30 t/d of

waste plastics throughput) in a demonstration test at a site next

to the Ube Ammonia plant. The pressurized two-stage

gasification technology has a use field of production of hydrogen

which is used for ammonia synthesis and fuel cell power

generation. The pressurized two-stage gasification technology is in

operation as a commercial plant (195 t/d of waste plastics

throughput) at Kawasaki of Showa Denko K.K. since 2003.

2.Features�The pressurized internal circulating fluidized bed boiler (PICFBC)

is structured applying the circulation flow technology of above-

described ICFBC. Accordingly, the load control is available

without varying the height of fluidized bed. In addition, cooling of

combustion gas is avoided because the intrabed heat transfer

tubes do not expose on the bed during load controlling action,

which minimizes the generation of CO2 and eases the maintaining

temperature at inlet of gas turbine. Since the wear problem of

heat transfer tube in bed is decreased, silica sand can be used

as fluidizing material, and the amount of limestone can be

minimized to a necessary level for the intrafurnace desulfurization,

thus suppressing the generation of ash. Furthermore, the main

combustion chamber has no intrabed heat transfer tube so that

the problem of interference of intrabed heat transfer tube against

the particle movement does not occur, which prevents the

generation of agglomeration.(the solidification of melted medium)

Photo 2 Overview of pressurized two-stage gasification plant

Photo 1 Overview of PICFBC

In charge of research and development: Center for Coal Utilization, Japan; Ebara CorporationProject type: Coal Production and Utilization Technology Promotion GrantPeriod: 1992-1998


19

1A5. Coal Partial Combustor Technology (CPC)


1.Background and outline of technology�

Owing to the abundant reserves and wide distribution of

production countries, coal has high supply stability, and is

positioned as an important energy source in the future.

Compared with other fuels such as oil and gas, however, coal

contains large amount of ash and nitrogen, thus has many issues

in use, including facility trouble caused by ash and significant

increase in NOx emissions. Furthermore, global warming issue

has become international concern in recent years, which raises

an urgent requirement of development of technology to reduce

emissions of CO2 which is one of the main cause materials of

global warming. In this respect, the world waits for the

development of technology of high efficient and environmentally

compatible utilization of coal which generates large amount of

CO2 per calorific value.

Coal Partial Combustor (CPC) is a furnace where coal and air are

injected at high speed into a swirling melting furnace in tangential

direction, thus conducting partial combustion (gasification) of coal

under the condition of high temperature, heavy load, and strong

reducing atmosphere, and after most of ash in coal is melted and

separated to remove, the produced fuel gas is subjected to

secondary combustion. That is, CPC is a technology of coal

gasification combustion in boiler or gas turbine to utilize coal at

high efficiency and environmentally compatible state. The CPC

has the normal pressure CPC technology and pressurized CPC

technology. The former conducts very low NOx combustion

through the gasification in boiler, or generates low calorific gas at

normal pressure. The latter achieves high efficiency power

generation by pressuring the gas on the basis of the developed

technology of the former, and by combining it with gas turbine.

2.Normal pressure coal partial combustor technology�

Boilers of fusion and combustion type aiming at volume-reduction

and detoxication of ash discharged from boiler and at use of

difficult-to-combust coal were constructed and are operating in

large number centering on Western countries. The conventional

melting and combustion method has advantages of high

combustion efficiency and recovery of ash as nontoxic molten

slag. However, the method has drawback of large NOx

emissions caused by high temperature combustion.

Responding to the issue, our technology development focused

on the development of coal partial combustor system aiming to

simultaneously achieve the fusion to remove ash from coal and

the low NOx combustion. The system adopted direct mount of

CPC to the side wall of boiler, and the combustible gas generated

in CPC is directly charged to the boiler furnace, where the gas is

completely combusted with charged air.

As medium to small coal fired boilers, CPC can significantly

reduce NOx emissions while maintaining the compactness of

boiler similar with the scale of oil fired boiler, and can recover all

the coal ash as molten slag.

The right figure shows schematic drawing of the normal pressure

CPC boiler.

Fig.1 Schematic drawing of normal pressure coal partial combustor (CPC) boiler

Preliminary

combustor

Combustion air

Pulverized coal

Preheating burner

Baffle Secondary

combustor

High temperature combustion gas

Molten slag

In charge of research and development: Center for Coal Utilization, Japan; Kawasaki Heavy Industries, Ltd.; Kawasaki Steel Corp.; Chubu Electric Power Co., Inc.; and Electric Power Development Co., Ltd.Project type: Coal Production and Utilization Technology Promotion GrantPeriod: 1978-1986 (9 years)



20

3.Pressurized coal partial combustor technology�

On the basis of the result of normal pressure CPC development,

the development of pressurized CPC technology began aiming at

the development of high efficiency power generation system by

pressurizing CPC and combining it with gas turbine.

The figure below shows rough flow chart of the pressurized CPC

pilot plant having 25 t/d of coal gasification capacity (operating at

oxygen 21%). The pilot plant ran the coal gas generation test

using CPC under pressure of 20 ata which can be applied to gas

turbine. The test proved the effectiveness of the pressurized PCP.

4.Issue and feasibility of practical application�

The normal pressure CPC technology has already been brought

into practical applications as low NOx emission technology in

swirling melting furnaces of municipal waste gasification melting

furnaces and in very low NOx boiler for heavy oil combustion.

Also the normal CPC technology is in the development stage of

coal ash melting type low NOx boiler. The pressurized CPC

technology is in the stage of completion of pilot plant test, and is

in the research and development stage in private sector aiming at

practical use of the technology. These basic technologies have

also been integrated with the development of biomass

gasification gas turbine power generation technology.

Fig.2 Rough flow chart of pressurized CPC pilot plant

Photo 1 Total view of pilot plant

Pressurized pulverized coal feeder

Pulverized coal production unit

Flux feeder

Liquid oxygen tank

Liquid nitrogen tank

Air compressor

Primary air compressor

Slag tank

Kerosene tank

Gas cooler Ceramic filter

Gas incinerator

Denitration unit

Cooler

Desulfurization unit

Char hopper

Char feeder


21

1A6. Pressurized Fluidized Bed Combustion Technology (PFBC)


1.Background and process outline�

(1)The research and development of pressurized fluidized bed

combined power generation technology was conducted at

Wakamatsu Coal Utilization Research Center (present

Wakamatsu Research Institute) of Electric Power Development

Co., Ltd. using the 71 MWePFBC Plant, which was the first PFBC

plant in Japan. The test plant was the first plant in the world in

terms of full-scale adoption of ceramic tube filter (CTF) which is

able to collect dust from high temperature and high pressure gas

at high performance. Outline of the process is shown in Fig. 1.

Fig. 1 Outline of PFBC process

(2)Outline of facilities

Plant output 71.0 MWe

Pressurized fluidized bed combustion once-through boiler (ABB-

IHI production)

Bubbling type pressurized fluidized bed, Coal water paste

(70-75%) injection type

Combustion temperature 860OC

Combustion air pressure 1 MPa

Ammonia water injection(Non-catalytic denitration)

Ceramic tube filter (CTF)

Ash recirculation cyclone

Main steam / Reheated steam593OC/593OC

Steam turbine

Gas turbine

Intercooler

Air

Coal, limestone,

water

CTF ash

Fuel nozzle

Pressurevessel

Deaerator

Condenser

Denitrationunit

Fuel slurry pump

Bottom ash (BM)Watersupplypump

Watersupplyheater

Economizer

In charge of research and development: Center for Coal Utilization, Japan; and Electric Power Development Co., Ltd.Project type: Coal Production and Utilization Technology Promotion GrantPeriod: 1989-1999 (11 years)


Yamada et al.: "Coal Combustion Power Generation Technology", Bulletin of the Japan Institute of Energy, Vol.82, No.11, November, pp822-829, (2003)

Reference


22


Detail design of the facilities began in FY1990, construction

began in April 1992, and facilities installation began in October

1992. Test operation began in April 1993, coal combustion

began in September 1993, and 100% load was achieved in

January 1994. The two-stage cyclone system passed the

examination before entering operation in September 1994, and

the CTF system passed the examination before operation in

December 1994. Phase 1 demonstration operation was

conducted until December 1997. After that, the plant was

modified to adopt the ash-recycle system. Phase 2

demonstration operation was conducted from August 1998 to

December 1999. The cumulative operating time of PFBC was

16,137 hours including 10,981 hours in Phase 1 and 5,156 hours

in Phase 2. In particular, Phase 2 achieved continuous operation

of 1,508 hours. Through the operation, valuable data and

findings were acquired in terms of performance and reliability.

These results have already been applied to the construction of

commercial facilities of the three electric power companies.

4.Issue and feasibility of practical application

The feature of PFBC is adaptability to urban-operation owing to

the excellent environment-compatible characteristics including 10

ppm or lower SOx emissions, 10 ppm of NOx emissions, and 1

mg/Nm3 or lower dust concentration, and to the reduced space

of plant owing to the elimination of desulfurization unit. These

advantageous characteristics are obtained by: the diversification

of applicable fuels such as difficult-to-combust or low grade

materials and waste, utilizing the superior combustion

performance; the in-bed desulfurization; the combination with

catalytic or non-catalytic denitration; and the high temperature

and high performance dust collection by CTF. The issue is to

improve economy by fully utilizing these characteristics of the

system and by selecting adequate location.

Object of PFBC technology development

(1) Increase in efficiency through the combined power generation

utilizing the pressurized fluidized bed combustion conditions:

(gross efficiency of 43%)

(2) Providing advanced environmental characteristics including:

SOx reduction through the in-bed desulfurization; NOx reduction

through the low temperature combustion (about 860OC); Dust

reduction by CTF; and CO2 reduction by increased efficiency.

(3) Space saving of plant through the compact design of boiler

adopting pressurized condition and the elimination of

desulfurization unit.

Result of PFBC technology development

(1) Gross efficiency of 43% level was achieved by increased

efficiency through the combined power generation utilizing the

pressurized fluidized bed combustion conditions.(2) SOx level of

about 5 ppm through the in-bed desulfurization, NOx level of

about 100 ppm through the low temperature combustion (about

860OC), and the dust level of less than 1 mg/Nm3 or less by CTF

was achieved.

PFBC development schedule

Basic and detail design

Construction of demonstration plant

Test operation and adjustment

Demonstration operation Phase 1

Modification

Demonstration operation Phase 2

FY1989Fiscal year

ItemFY1990 FY1991 FY1992 FY1993 FY1994 FY1995 FY1996 FY1997 FY1998 FY1999

IntegrationConstruction start

Test operation

Test operation

Modification

Interi

m as

sess

ment

Fina

l ass

essm

ent

2.Development object and technology to be developed


23

1A7. Advanced Pressurized Fluidized Bed Combustion Technology (A-PFBC)


1.Outline�

The development of coal utilization high efficiency power

generation technology is an urgent issue from the viewpoints of

reduction in greenhouse gases and of resource saving.

Technology A-PFBC is a further advanced technology of PFBC

(pressurized fluidized bed combustion). That is, the development

aimed to increase the temperature at inlet of gas turbine, (from

about 850OC to about 1,350OC), and to recover high temperature

steam, thus to attain higher efficiency of power generation (about

46% of net efficiency; about 40% for the current coal fired power

plants) by the combination of PFBC with the fluidized bed

gasification technology.

Fig. 1 Flowchart of A-PFBC combined power generation system

(1) High efficiency power generation [Net efficiency: about 46%]

- Increase of gas turbine inlet temperature

(from about 850OC to about 1,350OC)

- Recovery of high temperature steam

(High temperature steam recovery at the synthesis gas cooler

applying the high temperature desulfurizer)

(2) Mild gasification condition [Carbon conversion: about 85%]

- 100% gasification in the partial gasifier by the combination with

the oxdizer (perfect oxidizing atmosphere)

(3) Utilization of results of related technologies

- PFBC technology

- Various coal gasification technologies

2.Development object and technology to be developed

Limestone

Desulfurizer

PartialGasifier

Air

Coal

Char

Ash

Ash

Air

Oxdizer (PFBC)

Synthesis gas cooler

Ceramic FilerCyclone

Combustor

Gas turbine

Flue gas

Steam turbine

Gas Flow

Steam Flow

In charge of research and development: Center for Coal Utilization, Japan; Electric Power Development Co., Ltd.; Chubu Electric Power Co., Inc.; and Mitsubishi Heavy Industries, Ltd.Project type: Coal Production and Utilization Technology Promotion GrantPeriod: 1996-2002


Preprint for the 13th Coal Utilization Technology Congress, "A-PFBC"; sponsored by Center for Coal Utilization

Reference


24

Fig. 2 PDU: LAyout of three reactors


Aiming at the practical application of the above-described

system, the study team installed a small scale process

development unit (refer to the photograph of total view of PDU)

at Wakamatsu Research Inditnte (Kita Kyushu City) of Electric

Power Development Co., Ltd. The PDU test operation began in

July 2001. By the end of FY2002, the cumulative gasification

operation time reached 1,200 hours, and the continuous

gasification operation reached 190 hours. The PDU test

confirmed the three-reactors link operation, which is an

objective of the system validation, and acquired characteristics

of each reactors, thus confirmed the data necessary for scale up.

The development has an issue of validation of total system

combined with gas turbine at larger scale, or pilot plant scale.

(1) Outline of the test of the process development unit (PDU)

[Object of the test]

For the system of three-reactors combination (oxidizer, partial

gasifier, and desulfurizer), (refer to Fig. 2), the acquisition of

reaction characteristics and operation characteristics, and the

validation of the process are conducted to acquire the scale up

data.

- Validation of the three-reactor link process

- Confirmation of performance of individual facilities (oxidation,

gasification, desulfurization, etc.)

- Confirmation of basic operability

- Acquisition of various characteristics, acquisition of scale up

data, etc.

[Outline of facilities]

With the main object of validation of the system, the plant

contains limited range of facilities including the main three

reactors, (coal treated scale: 15 t/d). Gas turbine system and

steam turbine system are not installed in PDU because their

performance is available from similar systems.

Fig.3 PDU: Total view

A-PFBC development schedule

(1) Research plan, technology study

(2) Elementary test and F/S

(3) PDU test (15 t/d)

(4) Process evaluation

FY1996Fiscal year

ItemFY1997 FY1998 FY1999 FY2000 FY2001 FY2002

Design, manufacturing, and installation

Installation completion

Test operation

Partial gasifier

Desulfurizer

Oxidizer

Coal Fired Power Generation Technologies (Gasification Technologies)

25

1B1. Hydrogen-from-Coal Process (HYCOL)


1. Background and process outline�

The technology is a gasification technology utilizing spouted bed

in which pulverized coal with oxygen under high temperature and

high pressure condition. Trough the gasifier, we can obtain the

medium calorific value gas that is rich in hydrogen and carbon

monoxide. The technology is called the "HYCOL process".

Through the shift reaction, the gas yields carbon monoxide and

changes steam to carbon dioxide and hydrogen. After separating

the carbon monoxide and carbon dioxide, the gas is purified to become

high purity hydrogen.

Hydrogen is used in oil refinery and chemical industry, further in

coal liquefaction process. On the other hand, the obtained gas

containing carbon monoxide is expected to be used widely as a

raw material of chemical synthetic products, fuel for fuel cell, and

fuel in various industries.

The HYCOL process has the features described below.

(1)The process uses a dry-feed type one-chamber and two-stage

swirling spouted bed gasification furnace. Pulverized coal which

is pressurized in a lock hopper is fed, in dry state, to the

gasification furnace via burners in swirling mode. The burners

are arranged by four of them in each stage. The oxygen feed

and the coalification rate at upper stage and lower stage are

separately controlled. Through the operation, high thermal

efficiency is attained, and heavy load gasification is performed.

(2)The slag self-coating technology for the water cooled tubes

was developed. By the technology it is realized to prolong the life

of the tubes and to have reliability for the gasifier.

(3)The swirling gas flow distributor was developed and adopted

as the technology to easily and uniformly distribute coal to many burners.

(4)Ash in coal is melted in the gasification furnace. The melting

ash is discharged through the slug hole located on the hearth at

the furnece. As the result of the swirling gas flow, the high

temperature of the slag hole is maintained, and the smooth

flowdown of the slag is secured.

(5)The unreacted char discharged from the gasification furnace

accompanied with gas is separated by cyclone or other device to

recycle to the gasification furnace in high temperature and high

pressure state, thus ensuring complete reaction.

(6)Ash in coal is recovered as slag which does no elute toxic

ingredients. Together with the advantage of ready recovery of

sulfur-components and nitrogen components in a form of H2S

and NH3, respectively, the ash recovery significantly reduces the

environmental loads.

Coal to have lower melting point of ash or to have smaller fuel

ratio (fixed carbon to volatile matter) is more easily gasified.

2. Progress and result of the development�

HYCOL association (structured by above-listed nine private

companies) contracted the research and development agreement

on the pilot plant under supported by NEDO. On the other hand,

five private companies (Hitachi Ltd., Babcock-Hitachi K.K., Asahi

Glass Co., Ltd., Shinagawa Refractories Co., Ltd., and NGK

Spark Plug Co., Ltd.) contracted the basic study on the structure

of the furnace and on the materials with NEDO.

For establishing the process, the pilot plant was constructed at

Sodegaura, Chiba. The operational study of the pilot plant was

conducted from 1991 to 1994. The performance target was

achieved, and the world’s top gasification furnace technology was

established.


The development of coal gasification fuel cell system (IGFC) for

power generation utilizing HYCOL technology has begun from

1995, (EAGLE Project).

In charge of research and development: HYCOL Association [Idemitsu Kosan Co., Ltd. ; Osaka Gas Co., Ltd.; Electric Power Development Co., Ltd.; Tokyo Gas Co., Ltd.; Toho Gas Co., Ltd.; Nikko Kyoseki Co., Ltd.; The Japan Steel Works, Ltd.; Hitachi Ltd.; and Mitsui Coal Liquefaction Co., Ltd.]Contract project of NEDOProject type: Contract project of NEDO



26

Specification and target performance of pilot plant

Coal throughput

Gasification agent

Gasification pressure

Gasification temperature

O2/Coal

Product gas volume

Gas composition

(design)

Carbon conversion

Cool gas efficiency

max. 50 ton/day

Oxygen

30 kg/cm2(G)

1,500-1,800OC

0.8-0.9 (weight ratio)

about 91 kNm3/day

CO 61%

H2 31%

CO2 3%

98% or more

78 % or more

Fig.1 Flowchart of pilot plant

Pretreatment process Gasification process Water-washing process Product gas firing process

Desulfurization unit

Recycle gascompressor

Ash treatment process

Air heater

Pulverized coal apparatus

Coal

Lock hopper

Lock hopper

Gasification furnace

DistributorB

oile

r

Water-washing column

Waste heat boiler

Incinerationfurnace


27

1B2. Integrated Coal Gasification Combined Cycle (IGCC)


1. Outline and object of IGCC demonstration test�

Integrated Coal Gasification

Combined Cycle (IGCC) is a

high efficiency power

generation technology which

gasifies coal to be used as the

fuel for gas turbine. Japanese

power companies promoted

research and development of

IGCC technology applying the

Nakoso pilot plant (PP) type

gasifier1,2) as the core

technology3). The PP type

gasifier applies dry coal fed,

oxygen-enriched air blown,

pressurized two stage

entrained beds, as shown in

Figure 1, which is expected to

give higher efficiency than preceding gasifiers in abroad.

On the basis of the study results, the IGCC demonstration test

project was started with the aims to validate the reliability,

operability, maintenance ability, and profitability of IGCC, and to

confirm the feasibility of coal fired IGCC commercial plant.

Compared with conventional pulverized coal fired power plants ,

IGCC has many advantages as described below.

1. Increase in thermal efficiency---Compared with conventional

pulverized coal fired power plants, IGCC can increase net

thermal efficiency by about 20% for commercial plant.

2. Better environmental characteristics---Owing to the increase in

thermal efficiency, the emissions of SOx, NOx, and dust per

generated power are reduced. In addition, amount of CO2

emissions is reduced to the level of heavy oil fired power

generation process.

3. Increase in applicable grades of coal---IGCC can use coal,

having low ash melting points, which are difficult to be used in

conventional pulverized coal fired power plants. As a result,

IGCC widens the variety of coal grades applicable in coal fired

power plant.

4. Increase in applicable fields of ash---Since IGCC discharges

coal ash in a form of glassy molten slag, the ash is expected to

be effectively used as materials for civil works.

5. Reduction of water consumption---Owing to the direct

desulfurization of generated gas, IGCC does not need the flue

gas desulfurization unit which consumes large amount of water.

Accordingly, IGCC significantly reduces the water consumption

compared with conventional pulverized coal fired power plant.

2.Specification and object of IGCC demonstration plant�

Figure 2 shows the flow diagram of the IGCC demonstration

plant. Table 1 shows main specifications and target values of the

plant. Figure 3 shows conceptional drawing of IGCC

demonstration plant. The scale of IGCC demonstration plant(250

MW, 1700 t/d of coal feed) is about a half of commercial plant.

The gasifier is of the Nakoso PP type. Wet type gas clean up

system with MDEA is adopted . The gas turbine is the 1200OC-

class gas turbine corresponding to the output of 250 MW.

Table 1 Main specifications and target values of IGCC demonstration plant

Fig. 1 Nakoso PP type gasifier

Wet gas cleanup (MDEA) + Gypsum recovery

1200 OC - class

48%

42%

8 ppm (O2 16% conversion)

5 ppm (O2 16% conversion)

4 mg/Nm3 (O2 16% conversion)

250 MW class

about 1,700 t/d

Output

Coal feed rate

Type

Environmental characteristic(target value)

Target thermal efficiency (LHV)

Gasifier

Gas cleanup

Gas turbine

Gross efficiency

net efficiency

SOx emission concentration

NOx emission concentration

Dust emission concentration

Gas turbine

Combustor Air

Steam turbine

Stack

Waste heat recovery boiler

Air separator

OxygenNitrogen

Dry coal fed, air blown, pressurized two stage spouting beds

Fig.2 Flow diagram of IGCC demonstration plant

Syngas

Char recovery unit

CharReductor(gasification

chamber)

Coal

Coal

Air

Combustor (combustion chamber) Air

Molten slag

Slag hopperWater

Molten slag

Unreacted coal (char)

In charge of research and development: Clean Coal Power R&D Co., Ltd.(Until 2000, the study has been conducted as a joint activity of power companies led by The Tokyo Electric Power Co., Inc.)Project type: Grant for "Demonstration of Integrated Coal Gasification Combined Cycle Power Generation "/ the Agency of Natural Resources and Energy of the Ministry of Economy, Trade and IndustryPeriod: 1999-2009

Coal

Gasifier Heat exchanger Char

recovery unit

Gas cleanup

Heat exchangerGasifier



28

The IGCC demonstration test is conducted by Clean Coal Power

R&D Co., Ltd. (CCP R&D Co., Ltd.) which was established by

nine power companies and Electric Power Development Co., Ltd.

As for the project cost, 30% of the cost is national aid (Ministry of

Economy, Trade and Industry), and 70% is shared by total eleven

corporations: nine power companies, Electric Power

Development Co., Ltd., and Central Research Institute of Electric

Power Industry. (Refer to Fig. 4.)

5.Activities until now�

The pilot plant test (200 t/d of coal feed) which is the preliminary

stage of the demonstration test was carried out through a period

from 1986 to 1996 at Nakoso Power Plant of Joban Joint Power

Co., Ltd. in Iwaki City, Fukushima, (Fig. 5). The pilot plant test

was conducted jointly by nine power companies, Electric Power

Development Co., Ltd., and Central Research Institute of Electric

Power Industry, as a contracted project of NEDO. The pilot plant

test of 4,770 hours including 789 hours of continuous operation

test proved the practical applicability of the IGCC technology3).

�Based on the success of the pilot plant test, the demonstration

test reflected the optimum system which was selected by

feasibility study given by NEDO. Through various investigations,

the demonstration test will be conducted at the site of pilot plant

in Nakoso Power Plant of Joban Joint Power Co., Ltd. again.

4.Schedule and progress �

Table 2 shows the schedule of demonstration project. As of

January 2004, the detail design and the environmental

assessment are in progress. Plant operation and demonstration

test are scheduled to start from second half period of FY2007 for

about three years.

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Preliminary validation test

Design of demonstration plant

Environmental assessment

Construction of demonstration plant

Plant operation and demonstration test

Fiscal year

1) Shozo Kaneko,et.al., "250MW AIR BLOWN IGCC DEMONSTRATION PLANT PROJECT",

Proceeding of the ICOPE-03(2003),3-pp163~167

2) Christopher Higman,Maarten van der Burgt,"Gasifaication"(2003), pp126-128

3) Narimitsu Araki and Yoshiharu Hanai: Bulletin of Japan Energy, 75-9, (1996) pp839-850

References

Establishment ofCCP R&D Co., Ltd

Fig. 3 Conceptional drawing of IGCC demonstration plantFig. 4 Schem of demonstration project

Fig. 5 Planned site for demonstration test. (Iwaki City, Fukushima, site for pilot scale test)

METI

Joint project agreement

CCP R&D Co., Ltd.

Personnel

70% contribution

30% subsidy

Nine power companies

Electric Power Development Co., Ltd.

Central Research Institute of Electric Power Industry

Table 2 Schedule of IGCC demonstration project

3.Organization for executing the IGCC demonstration test

Combined cycleblock

Gasification train

Gas cleanup train

Nakoso Power Plant of Joban Joint Power Co., Ltd.

Executed site of pilot plant test; Planned site for demonstration test


29

1B3. Coal Energy Application for Gas, Liquid and Electricity (EAGLE)


1.1. Summary of technology�

The multi-purpose coal gas production technology development

(EAGLE) mentioned here aims, in an attempt to reduce

environmental load, (particularly, to decrease the amount of

greenhouse gas generated) at establishing a coal gasification

technology which is widely applicable to chemical materials,

hydrogen production, synthetic liquid fuel, electric power, and other

purposes through the development of the most advanced oxygen-

blown, single-chamber, two-stage swirling flow gasifier that permits

the high-efficiency production of synthetic gas (CO+H2). The

application of this gasifier and its combination with gas turbines,

steam turbines, and fuel cells further permit high-efficiency power

generation [Integrated Coal Gasification Fuel Cell Combined Cycle

(IGFC)], which will optimistically generate 30% less CO2 emissions

than that of existing thermal power plants.

2.Development targets and technology to be developed�

When applying coal gasification gas for IGFC and synthetic

fuel/hydrogen/chemical fertilizer production, it is necessary to set

targets to meet the refinement level required by fuel cells as well

as the catalyst since impurities contained in the gas such as

sulfur compounds may poison fuel cells and the reactor catalyst,

thereby weakening their performance. Although not so much has

been reported, even globally, about the effects of fuel cell-

poisoning materials (including halogen) in particular, the EAGLE

Project has established development targets as listed in the table

on the right with reference to DOE, MCFC Association, and other

reports.

Gas calorific value: 10,000 kJ/Nm3 or moreCarbon conversionrate: 98% or moreCold gas efficiency: 78% or moreGasification pressure: 2.5 Mpa

1,000 hours or more

Coal gasification performance

Continuous operation performance

Adaptability to various grades coal

Capability to scale up

Gas purification performance

Acquisition of gasification data for 5 or more grades coal having different properties from each otherAcquisition of data for scale up aiming at about 10 fold of scale upSulfur compounds: 1 ppm or less (precise desulfurizer outlet)Halogens: 1 ppm or less (precise desulfurizer outlet)Ammonia: 1 ppm or less (precise desulfurizer outlet)Dust: 1 mg/Nm3 or less (precise desulfurizer outlet)

Target item Target of development

Fig.1 Flowchart of EAGLE 150 t/d pilot plant

Pulverized coal

Gasifier SGC

Slag

Char

CompressorRectifier

Air separator

Filter

Air

Gas turbine facility

Precise desulfurizer

COS converter

SecondayScrubber

PrimaryScrubber

MDEAAbsorber

MDEARegenerator

Acid Gas Furnace

LimestoneAbsorber

Incinerator HRSG

Stack

In charge of research and development: New Energy and Industrial Technology Development Organization; Electric Power Development Co.,Ltd.; The Center for Coal Utilization, Japan; and Babcock Hitachi K.K. Project type: Coal Production and Utilization Technology Promotion Grant; and Grant for the Development of Advanced Technology for Generation of Fuel Gas for Fuel Cell DevelopmentPeriod: 1995-2006 (12 years)


Coal Gasification Facilities Gas Clean-up Facilities

1) Masao Sotooka: Coal Gasification Technology (II) - Coal Energy Application for Gas, Liquid and Electricity (EAGLE),

The Japan Institute of Energy, Vol.82, No.11, November, pp836-840, (2003)

Reference


30

3.The Process and its Prograss�

A joint team from New Energy and Industrial Technology

Development Organization and Electric Power Development Co.,

Ltd. among others promotes the project. The pilot plant (150 t/d)

was constructed on the grounds of the Wakamatsu Laboratory at

the Technology Development Center of Electric Power

Development Co., Ltd., (refer to photograph). The plant is

undergoing test operations.

4.Future issues and the feasibility of practical application�

Through the acquisition of basic characteristics and performance,

research and development is scheduled to acquire

characteristics of various grade coal, to acquire, analyze, and

evaluate data, and to establish operational control technology

with stepwise confirmation of reliability and identification and

analysis of issues related to improved gasification performance

and to long-term operation.

With respect to practical application and commercialization,

active promotion will be enhanced based on the results of the

testing, research, and development.

Photo 1 Total view of the pilot test facilities Fig.2 IGFC system

EAGLE development schedule

F/S

Primary test

Design of pilot plant

Construction of pilot plant

Test operation

1995Fiscal year

Item1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Analysis

Test operation

Construction

Design

Test

Fina

l ass

essm

ent

Gasifier

AirCoal

Air

Nitrogen

Oxygen

Syngascooler

Filter

Gas clean-up

Circulation blower

Catalyst burner

Circulation blower

Heat recovery boiler

Compressor

Expansion turbine

Gas turbine

HRSG

Steam turbine

Iron Making and General Industry Technologies (Iron Making Technologies)

31�

2A1. The Formed-Coke making Process (FCP)Members in charge of research and development


4.Progress of research and development

1.Outline�

The formed-coke process (FCP) starts from noncaking coal as

the main raw material, prepares formed coal using a binder, and

then carbonizes the coal in as-formed shape in a vertical furnace

to obtain coke.

2.Features�

The FCP has a series of steps including raw material processing,

forming, carbonizing the formed coal, and cooling the carbonized

coke. In particular, carbonizing and cooling steps are conducted

in a vertical furnace with closed system, providing many superior

features in terms of work environment, work productivity,

easiness of stop and start up, and narrow installation space to

those of conventional chamber oven process.

3.Result of study�

1. Production of formed coke from 100% noncaking coal

Pilot plant operation was given normally with 70% noncaking coal

and 30% caking coal. The operation with 100% noncaking coal

was also attained.

2.Establishing stable operation technology and engineering

technology

Long period of operation at the facility capacity of 200 t/d was

carried out. Production of 300 t/d (1.5 times the design capacity)

was achieved. Regarding the unit requirement of heat, 320

Mcal/t-formed coal was achieved.

3. Long period and continuous use of 20% formed coke in large

blast furnace

In an actual large blast furnace, long period and continuous

operation test was carried out for 74 days with normal 20% and

maximum 30% mixing rate of formed coke to confirm that the

formed coke is applicable similar to the chamber oven coke.

Table 1 Progress of research and development

8180791978 82 83 84 85 86

Core

Fiscal year

Pilot plant test

Construction

Test operation

In charge of research and development: Center for Coal Utilization, Japan; and Japan Iron and Steel FederationPeriod: 1978-1986 (9 years)



32

Flow chart of continuous formed-coke production

Noncaking coal

1.Drying

2.Pulverizing

3.Kneading

4.Forming

5.Carbonization furnace

6.Low temperature carbonizing zone

7.High temperature carbonizing zone

8.Cooling zone

Formed coal

Formed coke

9.Precooler10.Primary

cooler11.Electric precipitator

Main blower

(Generated gas)

Ammonia water

Tar

13.High temperature gas heating furnace

15.Ejector

14.Low temperature gas heating furnace

12.Decanter

Caking coal

Noncaking coal is the main raw material (60-80%). The coal is dried to 2-3% of water content: (i). The dried coal is pulverized: (ii). A binder is added to the pulverized coal, which mixture is then kneaded: (iii), and formed: (iv), thus obtaining the formed coal.

Forming stage

The liquid in the gas is introduced to the decanter (xii) to separate ammonia water and tar by decantation and precipitation. Each of these byproducts is sent to respective existing plants for further treatment. After treated, tar is reused as the binder for the formed coke.

Byproducts

The formed coal is charged to the carbonization furnace (v), where the coal passes through the low temperature carbonizing zone, and then the coal is heated to 1000OC in the high temperature carbonizing zone (vii) to undergo carbonization. The heat-up rate is controlled so as the coal not to generate collapse and break caused by bulging and shrinking. The carbonized coal (coke), is cooled to 100OC or lower temperature in the cooling zone (viii) by a normal temperature gas injected from the bottom of the furnace before discharged from the furnace.

Carbonizing stage

The coke oven gas (300-350OC) leaving the top of the furnace is cooled by the precooler (ix) and the primary cooler (x). After removing tar mist in (xi), most of the gas is recycled to the furnace. The surplus portion of the gas is withdrawn from the system, which is then subjected to rectification and desulfurization to become a clean fuel having high calorific value, (3800kcal/Nm3).

Generated gas

The gas after separating tar mist in the electric precipitator is heated to about 1000OC in the high temperature gas heating furnace (xiii), and then is injected to the high temperature carbonizing zone (vii). The gas heated to 450OC in the low temperature gas heating furnace (xiv) drives the ejector (xv). The ejector (xv) sucks the high temperature gas which was used to cool the coke to feed to the low temperature carbonizing zone (vi) at a gas temperature of about 600OC.

Gas recycle

Binder


33

2A2. Pulverized Coal Injection for Blast Furnace (PCI)


2.Development object and technology to be developed�

The introduced technology has field results in abroad.

Considering the differences in facility configuration and scale,

and in operating conditions between abroad and Japan, the study

team conducted tests and investigations focusing on the

following-listed items, and reflected the result on the design.

1. Pulverized coal combustion test: Evaluation of influence of

grade and size of pulverized coal; temperature, pressure, and

oxygen rich condition of air feed; and other variables.

2. Model plant test (1 t/h scale) for coal treatment, transportation,

and control.

3. Test on actual furnace injecting coal through a single tuyere:

Combustibility evaluation at the tuyere of actual furnace;

sampling and evaluation of coke inside the furnace.

4. Distribution of pulverized coal along circumference: With a

model of actual furnace size, grasping powder flow characteristic

and determining distribution accuracy.


Injection of pulverized coal to blast furnace in Japan began at

Oita No.1 blast furnace of Nippon Steel Corp. in 19811).

Although the main reducing material in blast furnace is coke, the

blast furnace operation during and after the 1960s adopted heavy

oil as an assistant fuel injecting from tuyere to enhance the

productivity, efficiency, and scale up. After the two times of oil

crisis, however, the high price of heavy oil forced the producers

to switch the blast furnace operation to all-coke operation, or the

reducing material had to fully depend on coke. Nevertheless,

introduction of inexpensive assistant fuel instead of heavy oil was

wanted to reduce the cost of blast furnace operation and to

secure stable operation of the blast furnace.

In this regard, Oita No.1 blast furnace introduced the ARMCO

type pulverized coal injection system first in Japan, (Fig.1). The

features of the system are the following.

1. High pressure transportation and injection lines have no

mechanical rotation part, which avoids troubles of wear and

damage.

2. Applied gas is not recycled to assure reliability of operation.

3. Distribution of pulverized coal charged to individual tuyeres

ensures uniform distribution utilizing the geometrically symmetric

flow characteristic of fluid.

4. Drying, pulverizing, and collecting coal are conducted in two

parallel lines to assure stable blast furnace operation.

5. Flow velocity of carrier air and pressure resistance of facilities are

determined with full consideration of preventing fire and explosion.

Fig.1 Pulverized coal injection facility at Oita No.1 blast furnace


Considering the heavy oil injection level during increased

production rate period and the experienced long time result, the

capacity of Oita No.1 blast furnace was designed to 80 kg/t. Two

lines of mill each having 25 t/h capacity were installed. After the

start of the plant, facility operation and injection operation

proceeded smoothly to establish the stable production system.

After the success of Oita No.1 blast furnace, Godo Steel, Ltd.

started the operation of the exclusively-developed system in

1982. Following the domestic technology, Kobe Steel, Ltd.

introduced the U.S. Petrocarb technology and constructed

Kakogawa No.2 blast furnace and Kobe No.3 blast furnace in

1983 as the Kobelco system. After that, Nippon Steel Nagoya

No.1 blast furnace of ARMCO type and Nisshin Steel Kure No.2

blast furnace of ARMCO type entered commercial operation in

1984. In 1986, the pulverized coal injection facility for blast

furnace was adopted by 16 blast furnaces in Japan, accounting

Receivinghopper

P.A.fan

Air heater Pulverizer

Feeder

Raw coal bunker

Reservoirtank

1 2 3

O.T.

Bag Filter

Cyclone

Feed tank furnace

Tran

spor

t lin

e

Dis

pers

er

Distributor

N2 compressor

Air compressor

In charge of research and development: Nippon Steel Corp. and other blast furnace steel making companies Period: Introducing the technology successively to domestic blast furnaces starting from 1981



34

Shinjiro Waguri: Ferram vol.8, p371 (2003)

Reference

Fig. 2 Increase in applications of pulverized coal injection for blast furnace in Japan

4.Issues and feasibility of practical application�

Average operating years of domestic coke ovens have reached

around 30 years, and the importance of the technology of

injection of pulverized coal as an assistant fuel for blast furnace

increases year after year. Compared with coke which depends on

caking coal, pulverized coal increases the expectation for the

injection material owing to the flexible adaptability to the coal

resources. The technology of pulverized coal injection has a

possibility of innovation of blast furnace toward a combined

smelting furnace through the combined injection via tuyeres of

blast furnace together with reducing materials such as waste

plastics and biomass, and further with reducing ores. Thus, the

technology is expected to develop as a core technology of blast

furnace solving the issues of resources, energy, and carbon

dioxide.

for 50% of the total. The number increased to 25 blast furnaces

in 1996. In 1998, all the operating domestic blast furnaces had

the pulverized coal injection facility, which increased the domestic

average pulverized coal ratio to 130 kg/t level, (Fig. 2). Table 1

shows the various types of injection for the blast furnace

pulverized coal facilities. Table 2 shows the highest level in

Japan of a typical operational index of blast furnace during the

operation with pulverized coal injection.

Table 1 Various facility types of pulverized coal injection to blast furnace

Petrocarb

DENKA

Kuettner

ex-PW

Simon Macawber

Klockner

Pneumatic conveying from feed tank directly

to each tuyere

Carrier gas pressure and flow rate (Downtake)

Rotary Feeder+Uniform pressure drop (one way) distribution

ditto (Uptake)

ditto + Flow meter

Rotary Valve

Coal Pump

National Steel, Kobe Steel,JFE (NKK)

JFE (Kawasaki Steel)

Thyssen

Dunkerque

Scunthorpe

Feed tank Main pipe Distributor

Tuyere

Low

Low

High

Medium

Low

Low

High

High

Low

High

High

Low

Low

High

High

Low

Low

Low

Medium

Medium

Large

Medium

Large

Small

Small

Small

Medium

Table 2 Domestic highest level operation indexes for blast furnace operation with pulverized coal injection

200

150

100

50

0

550

500

450

400

350

PC

rat

e(kg

/t-pi

g),N

umbe

r of

PC

IBF

Cok

e R

ate(

kg/t-

pig)

1980 1990year

coke rate(mean) PC rate(mean)

number of BF equiped PCI

2000

Yearand

MonthSteel works, blast furnace

Coal dust ratiokg/t

Coke ratiokg/t

Reducing material ratiokg/t

Tapping ratio t/d/m3

Maximum pulverized coal ratio (PCR)

Minimum coke ratio (CR)

Minimum reducing material ratio (RAR)

Maximum tapping ratio

98.6

99.3

94.3

97.1

Fukuyama No.3 blast furnace

Kobe No.3 blast furnace

Oita No.1 blast furnace

Nagoya No.1 blast furnace

266

214

122

137

289

288

342

350

555

502

464

487

1.84

2.06�

1.95�

2.63

Type of distribution/transportation

Control of flow rate in branched pipe

UseName of type InvestmentVelocityPneumaticconveying

concentration

Uniformly distributing to give uniform pressure drop across in individual pipes

Uniformly distribution by throttled pipes

ditto

ARMCO

new PW

Nippon Steel Corp., Hoogovens

Sidmar, Solac Fod

Dunkerque, Taranto

Sumitomo Metal Mining. Co., Ltd.

Sumitomo Metal Mining. Co., Ltd.


35

2A3. Direct Iron Ore Smelting Reduction Process (DIOS)


1) Core technology study (FY1988-FY1990)

Core technologies necessary for the construction of pilot plant

were established. These core technologies include the increase

in thermal efficiency of smelting reduction furnace (SRF), the

connection with preliminary reduction furnace (PRF), the molten

slag discharge technology, and the SRF scale up.

2) Pilot plant test (FY1993-FY1995)

1. Applicability of direct use of powder and granular ore and coal

was confirmed, and necessary facility conditions were

determined.

2. With various raw materials, the conditions of facilities and of

operation to achieve high thermal efficiency to substitute the blast

furnace were determined.

3. Technology for water cooling of furnace body was established.

Conceptual design and economy evaluation (FS) for commercial

facilities were conducted. The conditions of facilities and of

operation to prove the superiority to the blast furnace as shown in

the results of the research was clarified.

1.Outline�

The DIOS directly uses noncaking coal in powder or granular

shape and iron ore without using coke process and sintering

process which are required in blast furnace process. The

noncaking coal is directly charged to a smelting reduction

furnace, while the iron ore is preliminarily reduced before

charged to the furnace, thus the molten iron is produced.

2.Features�

1. Applicable of inexpensive raw material and fuel, (noncaking

coal, in-house dust, etc.)

2. Low operation cost

3.Responding flexibly to variations of production rate

4. Compact facilities, and low additional investment

5. Available in stable supply of high quality iron source

6. Effective use of coal energy

7. Easy coproduction of energy (cogeneration)

8. Low environmental load, (low SOx, NOx, CO2, dust

generation, no coke oven gas leak)

3.Result of study�

Feasibility study was given to new installation of commercial

plant of blast furnace process and of DIOS at seaside green field.

Considering its superiority to blast furnace process as described

below, the feasibility of DIOS can be demonstrated for the model

of 6,000 tons of molten iron production (annual production of 2

million tons).

1. Investment cost is decreased by 35%.

2. Molten iron production cost is decreased by 19%.

3. Coal consumption per 1 ton of molten iron production is the

same level with that of the blast furnace process, 730-750 kg.

4. Net energy consumption is decreased by 3 to 4%.

5. CO2 emissions in the iron making process is decreased by 4 to 5%.

Table 1 Progress of research and development

90891988 91 92 93 94 95

Core

Fiscal year

Pilot plant testConstruction

Test operation

4.Progress of research and development

In charge of research and development: Center for Coal Utilization, Japan; and Japan Iron and Steel Federation Period:1988-1995 (8 years)



36

Fig.1 An example of the DIOS pilot plant operation (per 1,000kg of molten iron)

Coal952kg

Flux80kg

Iron ore1450kg

Preheating furnace

RD 8.7%

RD 8.6%600OC

2,326Nm3

2,789Mcal(11.7GJ)

Venturi scrubber

Pressure control value

Off-gas

Smelting reduction furnace1.9kg/cm2 - G(290kPa)

N2 70Nm3

Tapping device

RD 27.0%779OC

O2

608Nm3 RD 27.1%

OD 31.6%

Prereductionfurnace

Plant size

Smelting reduction furnace

Prereduction furnace

500 t-molten iron/day

Height 9.3m.Inner diameter 3.7m.Pressure less than 2.0kg/cm2 - G(300kPa)

Height 8.0m.Inner diameter 2.7m.

Legend

Oxidation degree

Reduction degree

OD :

RD :

24.7t/h1,540OC1,000kg

Molten iron


37

2A4.



The existing coke production process,which rapidly heats the coal

at 350OC(low temperature carbonization),as opposed to the old

method of a 1200OC coke furnace, has many problems such as

unavoidable coal grade limitation of using mainly strong caking

coke owing to the limitation of coke strength, large energy

consumption owing to the process characteristic, and

environmental issues. Coke ovens in Japan have reached their

average life of 30 years, and enter their replacement time. In this

occasion of requirement for replacement, there is a need to

develop an innovative next-generation coke production technology

that has flexibility to handle coal resource and that has excellent

environmental measures, energy saving, and productivity.

Responding to the need, the team develops a new coke process.

The SCOPE21 process aims to develop an innovative process

responding to the need in 21st century in terms of effective use of

coal resource, improvement in productivity, and environmental

and energy technologies. As shown in the figure, the existing

coke production process is divided into three stages along the

process flow, namely the coal rapid heating, the rapid carbonization,

and the medium-to-low temperature coke reforming. Development

was carried out of a revolutionary process with overall balance

that pursued the functions of each stage the utmost.

Currently the SCOPE21 is only one large development project for

new coke process in the world, and it is hoped that it can be put

to practicul use.

Fig.1 Outline of the next-generation coke oven process


(1)Increasing the use ratio of noncaking coal to 50%

With the aim of increasing the use ratio of noncaking coal to

50%, which noncaking coal is not suitable for coke production

and the current use ratio is only about 20%, the study develops

the technology to increase the bulk density of charging coal

through the improvement of caking property utilizing the coal

rapid heating technology and through the forming treatment of

fine coal powder.

(2)Increasing the productivity by three times

Aiming at the increase in the productivity by three times that of

current level, the study significantly reduces the carbonizing time

by increasing the thermal conductivity of wall of the carbonizing

chamber and by discharging the material at temperatures lower

than normal carbonization point, (medium-to-low temperature

carbonization). The resulting insufficient carbonization

temperature is compensated by reheating in the coke dry

quenching unit (CDQ) to secure the product quality.

(3)Reducing NOx generation by 30% and achieving smokeless,

odorless, and dustless operation

Full scale prevention of generation of smoke, odor, and dust

Hot briquetting machine

Pneumaticpreheater

Emission freecoke pushing

Fine coalCoarse coal

StackCoal

Fluidizedbed dryer

FuelHot blast stove

Plug flow conveying system

Stationary charge unit

Highly sealed oven door

Carbonizing chamber

High heat conductivity brickPressure control (750-850OC)

Regenerator

Foundation

Flue gas

Smokeless discharge

Coke upgrading

Power plantSteam

Coke (150-200OC)

Coke sealed transportation (750-850OC)

Blast furnace

In charge of research and development: Center for Coal Utilization, Japan; and Japan Iron and Steel FederationProject type: Coal Production and Utilization Technology Promotion GrantPeriod:1994-2003 (10 years)

Super Coke Oven for Productivity and Environment Enhancement �toward the 21st Century (SCOPE21)�



38


The project proceeds under the joint work of Center for Coal

Utilization, Japan and Japan Iron and Steel Federation. The pilot

plant (6 t/h) was constructed in Nagoya Works of Nippon Steel

Corp., (refer to photograph), and the test operation was conducted.

(4)Issue and feasibility of practical application�

The aging of coke ovens in Japan proceeds, though there are

progresses of furnace repair technology. Thus coke ovens still

need replacement and the replacement schedule has not been

changed. The developed technology will be introduced to these

aged coke ovens, though it is influenced by the economic

conditions.

Photo 1 Total view of pilot plant

SCOPE21 Development schedule

96951994 97 98 99 2000 01 02 03

Survey and study

Core technology development

Pilot plant studyConstruction

during coke production is attained by the sealed transportation of

coal using the plug transportation, the sealed transportation of

coke, and the prevention of gas leak from coke oven applying

intrafurnace pressure control. Furthermore, improved combustor

structure of the coke oven reduces NOx generation.

(4)Saving energy by 20%

The energy necessary to produce coke is aimed to reduce by

20% through the increase in the temperature to start the

carbonization by preheating the charging coal to high

temperature, the reduction in the carbonization heat by reducing

the discharging temperature applying medium-to-low temperature

carbonization, and the easy recovery of sensible heat of

generated gas and of combustion flue gas owing to the scale-

reduction of facilities resulted by the increased productivity.

1) Kunihiko Nishioka et al.: Lecture papers at the 12th Coal Utilization Technology Congress, Tokyo, p.1-2.1, November (2002)

Reference

800

600

400

200

0

100

80

60

40

20

0

Conventional SCOPE21 Conventional SCOPE21

Ene

rgy

cons

umpt

ion

(Mca

l/t-c

oal)

70

133

460

600

Variable 47

Variable 38

�C

oke

Pro

duct

ion

cost

(%

)

Fixed 53 Fixed

44

PowerFuel gas

Total 399

Total 316

[Evaluation consumption] [Reduction of coke production costs]Energy saving�Reduction of total energy use by 21% due to adopting a pretreatment process with direct heating of coal and a high effciency coke oven with a heat recovery system.

Construction costs�Reduction by 16% by greatly reducing the number of coke ovens even while expanding the coal pretreatment plants and environmental protection.�

Coke production cost�Reduction by 18% by increasing the poor coking coal ratio and decreasing construction costs even while increasing electricity and fuel gas in the coal pretreatment plant.

Energy saving and Economical Evaluation�The SCOPE21 process is composed of innovative technologies, enabling effective use of coal resources, energy saving, and environment enhancement. As a result, it has a great economical advantage over the conventional process.

Conventional

SCOPE21

Coke overCoal

Preliminary Common equipment Total

100

84

11

19

[Reduction of construction costs]

Disassembly and investigation

Core technology combination test

Test operation

CDORecovered

271CDO

recovered 277

89

40

---

25

Iron Making and General Industry Technologies (General Industry Technologies)

39

2B1. Fluidized Bed Advanced Cement Kiln System (FAKS)



The FAKS is configurated by a granulation sintering kiln and two-

stage coolers. The granulation sintering kiln granulates the raw

material to a specific size for melting to high quality cement, and

then sinters thus granulated raw material at high temperatures.

The two-stage coolers combine a fluidized bed cooler and a

packed bed slow-cooling cooler to increase the heat recovery

efficiency.

The most important technology in the system is the granulation

control technology. Compared with the other development which

needed "charge of the seed-core clinker as the core of the

granule from outer side for controlling the granulation process,

thus allowing high temperature raw material to adhere and grow

on the seed-core clinker", the FAKS process applies "hot self-

granulation" for the first time in the world. The "hot self-

granulation" is "the process where a nucleus of granule is

generated by agglomerating the small particle of raw material,

and to allow other raw material to adhere and grow on the

nucleus, thus to conduct the granulation control."

The granulation sintering kiln furnace integrates two major

technologies for performing the granulation control: a raw

material injection unit, and a bottom classification and discharge

unit.

1.Features�

The objectives of development of fluidized bed advanced cement

kiln system (FAKS) are the efficient combustion of low grade

coal, the significant reduction of NOx emissions, and increase in

the heat recovery efficiency between solids and gases

discharged from the process by utilizing the inherent

characteristics of fluidized bed process, including combustion

performance, heat transfer performance, particle diffusion and

granulation properties. Thus, the ultimate object of the

development is to contribute to the global environment

conservation, the energy saving, and the fulfillment of demand of

various kind and/or special grade cement.

Photo 2 Total view of 200 t/d plant

Fig.1 FAKS-I System structure

Photo 1 Clinker produced from fluidized bed kiln

Cement clinker



40

1) Isao Hashimoto, Tatsuya Watanabe, et al.: Development of Fluidized Bed Advanced Cement Kiln Process Technology (Part 9),

The 8th Coal Utilization Technology Congress, Japan, September (1998)

Reference

Comparison of rotary kiln type process and FAKS at a 1,000 t/d plant in terms of environmental improvement effect

Fig.2 Key Technology

3.Demonstration site and use field�

1)Demonstration site : Tochigi plant of Sumitomo Osaka Cement

Co., Ltd.

2)Use field : Cement production

3)Development period : 1996-1998

4.Progress of development�

On the result of basic study begun from 1984 by the joint team of

Kawasaki Heavy Industries, Ltd. and Sumitomo Osaka Cement

Co., Ltd., the technology development proceeded beginning from

1986 as the Coal Production and Utilization Technology

Promotion Grant project which is a project of Agency of Natural

Resources and Energy of the Ministry of International Trade and

Industry. A 20 t/d pilot plant was constructed in June 1989 jointly

by Center for Coal Utilization, Japan, Kawasaki Heavy Industries,

Ltd., and Sumitomo Osaka Cement Co., Ltd. Then the pilot plant

operation test began. From April 1993, the basic plan and design

started for a 200 t/d plant jointly by Center for Coal Utilization,

Japan, and Japan Cement Association. Through the operation

test toward the practical application begun from February 1996,

the system was validated, and the development work completed

at the end of December 1997.

5.Issues�

The performance comparison between the conventional

technology and FAKS for a 1,000 t/d commercial plant is shown

in the table below. The FAKS is expected to be commercially

adopted as an innovative substitute cement production

technology.

476

233

220

108x103

1,000

1,050

330

2,993x103�

36�

1.49�

25,116

708

341

245

118x103

1,000

1,050

330

3,411x103�

27

1.46�

25,116

Discharge quantity (mg/Nm3)

Annual discharge quantity(ton-NO2/year)

Discharge quantity(g/Nm3)

Annual discharge quantity (ton-CO2/year)

ton-clinker/day

ton-cement/day

Day/year

kJ/ton-clinker

KWh/ton-clinker

Nm3/kg-clinker

kJ/kg-coal

NO2

as N content in coal is 1% andNOx convert in 10% O2

Discharge quantity Rotary Kiln & AQC FAKS

*1 Based on IPCC : Guideline for National Greenhouse Gas Inventories, Reference Manual Carbon Emission Coefficient / Basic Calculation ; Carbon Emission Factor = 26.8 tC/TJ , Fraction of Carbon oxidized = 0.98

CO2 *1

depends on electric power and fuel consumption

Basis of calculation

Production capacity

Annual operating time

Heat consumption

Power consumption

Exhaust gas specific quantity

Lower calorific value of coal

Iron Making and General Industry Technologies (General Industry Technologies)

41

2B2. New Scrap Recycling Process (NSR)


2.Development schedule�

The development was promoted by a joint team of Center for

Coal Utilization, Japan, Nippon Sanso Corp., and NKK Corp.

(present JFE Steel Corporation). The main subject of development

was the furnace structure and the burner arrangement to attain high

efficiency melting. The study began from a batchwise melting

furnace. With the result of the batch-furnace operation, the

continuous melting furnace was developed aiming at higher

energy efficiency.

1.Background �

In Japan, currently about 30 million tons of iron scrap is recycled

every year, and most of them are melted in arc furnaces

consuming large amount of electric power. The energy efficiency

of arc furnace is as low as about 25% (converted to primary

energy taking into account of efficiency of power generation and

of power transmission). Thus a melting process having higher

energy efficiency is wanted. To this point, the NSR process is a

non-power melting technology that melts metals such as iron

scrap utilizing high temperature energy obtained from direct

combustion of pulverized coal by oxygen. The NSR process has

been developed aiming to significantly increase the energy

efficiency compared with that of conventional technology.

Fig. 2 Pilot plant (6t/h)

Table 1 Development schedule

Fig. 1 NSR process flow

Survey

Bench scale (1 t/batch)

Pilot plant scale (5 t/batch)

Continuous furnace (pilot plant scale: 6 t/h)

1992 1993 1994 1995 1996 1997

Batch-furnace

3.Outline of process and result of study�

Figure 1 shows the process outline of the continuous melting

furnace. The melting furnace has a melting section, basin

section, and holding section, each of which is separately

functioned. Each section has pulverized coal - oxygen burner.

The oxygen supplied to the burner is preheated to high

temperatures (400-600OC) by an oxygen preheater to combust

the pulverized coal.

With the above-described system, even pulverized coal normally

giving slow combustion rate can be combusted at high rate and

high efficiency similar with those of liquid fuel such as heavy oil.

The melting section is in shaft shape, where the raw material

charged from top of the furnace is directly melted by the burner

Oxygen generator

Pulverized coal tank

Pulverized coal charge unit

Burner controller

Oxygen preheater

Bag filter

Flue gas

BlowerRaw material

Open/close damper

Slide gate

Pulverized coal oxygen burner

Nitrogen �generator

Tuyere

Molten steel

In charge of research and development: Center for Coal Utilization, Japan; Nippon Sanso Corp.; and NKK Corp. (present JFE Steel Corporation)Project type: Coal Production and Utilization Technology Promotion GrantPeriod:1992-1997 (6 years)



42

1) Hiroshi Igarashi, Toshio Suwa, Yukinori Ariga, and Nobuaki Kobayashi: ZAIRYO TO PROCESS (Materials and Processes), Vo.12, No.1, p135 (1999)

2) Hiroshi Igarashi, Nobuaki Kobayashi, and Hiroyuki Nakabayashi: Technical Bulletin of Nippon Sanso Corp., (19) pp30-37 (2000)

References

flame at lower section of the furnace. The melted raw material

flows through the basin section and enters the holding section.

The basin section soaks the molten steel. The carbon content of

the molten steel in the basin section can be controlled by

injecting powder coke into the furnace. The holding section

stores the molten steel for a specified period, and rapidly heats

the molten steel to about 1,600OC, and then taps the molten steel

by the EBT system. To the basin section and the holding section,

molten steel agitation gas is injected from bottom of the

respective furnaces to enhance the heat transfer from flame to

molten steel and the slag-metal reaction. All the combustion gas

coming from individual sections passes through the melting

section, and is vented from the furnace top after being used to

preheat the raw material in the melting section. The raw material

is continuously charged from the furnace top and melted in the

furnace. The tapping from the holding section is conducted

intermittently.

The process effectively utilizes the heat transfer characteristics of

oxygen burner, and achieves high efficiency melting. Figure 3

shows the result of comparison of melting energy between the

process and the arc furnace. The electric power (oxygen is also

added because it is produced by electricity) is counted to the

primary energy including loss of power generation and of power

transmission. Compared with normal arc furnace, the melting

energy was reduced by 40%, achieving high energy efficiency.

Furthermore, the process achieved highly superior result to the

conventional process in terms of environmental measures such

as the significant suppression of generation of dust (excluding

ash in pulverized coal) and of dioxins owing to the control of

intrafurnace atmosphere.

Fig. 3 Comparison of melting energy

1600

EAF(380Wh/T)

Mel

ting

ener

gy(M

cal/T

)

Electric power

Pulverized coal

NSR

1400

1200

1000

800

600

400

200

0

Oxygen

Coke

4.Toward practical application�

The study team has already completed the design for actual

scale facilities. With the influence of current poor economy in the

electric furnace industry, however, the process has not been

brought into practical application. Nevertheless, since the

process is a non-power melting technology which is few in the

world, and has a strong advantage of not influenced by electric

power infrastructure, the study team continues to make efforts

toward the practical applications also in abroad.

Fig. 4 Commercial scale plant (50 t/h)

43

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

Three liquefaction processes

250 t/d design

Construction

Operation

Cleaning, etc.

Research on dismantlement

Removal

The Sunshine Project started (July, 1974)Research on three liquefaction processes started.

(1) Solvent Extraction Process (2) Direct Hydrogenation Process (3) Solvolysis Process

NEDO established (Oct. 1, 1980), succeeding three liquefaction processes of Coal Technology Development Office.

1st interim report (the same as the Joint Council report mentioned below)(Aug., 1983) The unification of three liquefaction processes recommended.NEDO set out for conceptual pilot plant planning (three processes and a proposal for their unification)

Unification of three processes/development of NEDOL Process

-NCOL established (Oct. 1, 1984)

PDU (1 t/d of Sumitomo Metals-Hasaki)-based PSU (1 t/d of Nippon Steel-Kimitsu)-based research (design) started (around 1985). PSU operation research started (1987).

A 150 t/d pilot plant started. (Downscaled from 250 t/d to 150 t/d.)

Review of total project costs toward reduction (April, 1991, agreed upon at the operation meeting.) -Kashima Establishment opened (Oct. 1, 1991). -The ground-breaking ceremony for a pilot plant held (Nov. 25, 1991)Construction NEDO

,s Coal Technology Development Office reorganized into CCTC (Oct., 1992).

Total project costs reconsidered to be clearly defined in value (Nov., 1992). Set at 68.8 billion yen.

The New Sunshine Project costs (1993)

Recommendations to the 48th Subcommittee Meeting for Coal Conversion (March, 1995) The period of research extended for completion (March 31, 1999) -The Research Center inaugurated (June 24, 1995) -The ground-breaking ceremony for a pilot plant held (July 10,1996) -Coal-in trial run (Nov. 26-29, 1996, Feb. 25-27, 1997)

-Coal-in RUN-1 (March 26, 1997-)

-Coal-in RUN-7 (-Sept. 9, 1998)

Total coal-in time of 6,062 hours or 262 days (excluding that for trial runs) The longest coal-in continuous run time of 1,921 hours

-Operation completion ceremony held on Sept. 29, 1998. -Pilot plant operation completion report meeting held (Dec. 1, 1998) at a Gakushi Kaikan hall. -Pilot plant operation research completed (March 31, 2000).

Year Articles and others

Development History of NEDOL Process

Conceptual design of 250 t/d

Basic conceptConceptual designpreparation

150 t/d design

Multi-Purpose Coal Utilization Technologies (Liquefaction Technologies)

3A1. Coal Liquefaction Technology Development in Japan


1.Background of Coal Liquefaction Technology Development�

Since the Industrial Revolution, coal has been used as an

important source of energy by humankind. Coal consumption

surpassed that of firewood and charcoal for the first time in the

latter half of the nineteenth century, making coal the world’s

major source of energy. In Japan, coal also became the

predominant energy source in the twentieth century. In the

1960s, however, the presence of coal gradually faded as it was

replaced by easier-to-use oil. It was after the oil crises of 1973

and 1978 that coal was thought highly of once again. With the oil

crises as a turning point, the development of oil-alternative

energy, particularly coal utilization technology, came under the

spotlight amid calls for the diversification of energy sources.

During that time, liquefaction of coal, which had been positioned

as the strongest oil-alternative energy contender because of its

huge reserves, was undergoing development in many countries.

Research in Germany and the United States involved pilot plants

with the capacity to treat hundreds of tons of coal per day.

In Japan as well, development of coal liquefaction technology

was being promoted under the Sunshine Project mainly by the

New Energy and Industrial Technology Development

Organization (NEDO). Despite the lag of a decade or so behind

Germany and the United States, slow but steady development

progress led to the successful completion of operations of a 150

t/d-scale pilot plant for the liquefaction of bituminous coal in 1998

with substantial results, thereby drawing equal with Germany and

the United States as well as establishing state-of-the-art coal

liquefaction technology. Coal-producing countries such as China

and Indonesia are also strongly interested in the

commercialization of coal liquefaction technology, with high

expectations for its future development.

2.History of Coal Liquefaction Technology Development in Japan�

2.1 Dawning of coal liquefaction technology development�

Between around 1920 and 1930, South Manchurian Railway Co.,

Ltd. started basic research on coal liquefaction using the Bergius

Process and, around 1935, initiated operation of a bench-scale

PDU (process development unit) plant. Based on this research,

a plant annually producing twenty thousand tons of coal oil was

built at Wushun Coal Mine, China, and operated until 1943. In

the meantime, Korean Artificial Petroleum Co., Ltd. succeeded

between 1938 and 1943 at its Agochi factory in the continuous

operation of a direct coal liquefaction plant capable of treating

100 t/d of coal. Production of coal oil at both of the above plants

was suspended at the request of the military to use the plants for

hydrogenation of heavy oil or to produce methanol.

At around 1930, besides the direct coal liquefaction method

(Fischer Process), the Bergius Process was used as an indirect

coal liquefaction method to study coal liquefaction technology

and to produce synthetic oil. The Fischer Process was

introduced into Japan upon its announcement in Germany in

1935 and, in 1937, plant construction started in Miike, winding up

in 1940 with the completion of an oil synthesis plant annually

producing thirty thousand tons of coal oil.

Under the background of a wartime situation, production of

synthetic oil was continued until the end of World War II.

2.2 Post-war research on coal liquefaction�

Immediately after the war, the U.S. Armed Forces Headquarters

banned research into coal liquefaction, alleging that it was

military research. In 1955, coal liquefaction research was

resumed at national laboratories and universities. This was not,

however, research on coal oil production but the production of

chemicals from high-pressure hydrocracking of coal, which was

continued until around 1975.

The Sunshine Project was inaugurated in 1974 on the heels of

the first oil crisis, encouraging efforts to devise liquefaction

technology unique to Japan as part of an oil-alternative energy

development program. Under the Sunshine Project, technological

development has been undertaken for the three coal liquefaction

processes of Solvolysis, Solvent Extraction, and Direct

Hydrogenation to liquefy bituminous coal. R&D of brown coal


MONGOLIA

TAIWAN

NEIMONGGOL

HEILONGJIANG

JILIN

LIAONING

HEBEI

SHANXI

SHAANXI

NINGXIA HUIZU

HENAN

HUBEI

ANHUI

ZHEJIANG

FUJIAN

JIANGXIHUNAN

GUIZHOU

SICHUAN

GANSU

QINGHAI

GUANGXI ZHUANGZUGUANGDONG

SHANDONG

JIANGSU

Beijing

Harbin

Kunming

44


3. Coal Liquefaction in the Future�

China, expecting stringency in its oil supply-demand situation for

sometime in the future, takes an active stance toward the

development/adoption of coal liquefaction technology. NEDO, as

part of its international cooperation program, installed 0.1 t/d

liquefaction equipment in China in 1982 for subsequent utilization

such as in liquefaction tests of Chinese coal, exploration of catalysts

for liquefaction, and human capacity building. Since 1997, at the

request of China, cooperation has been offered for the

implementation of feasibility studies on the location of a coal

liquefaction plant using Yilan coal of Heilongjiang Province.

Furthermore, a survey entrusted by China estimates Shenhua coal

reserves in Shenxi Province/Inner Mongolia Autonomous Region at

as much as 200 billion tons, justifying high expectations for coal as

an inexpensive source of energy.

It is further considered certain that Indonesia will become a net oil-

importing country in the near future. In 1992, the Indonesian

government requested cooperation in coal liquefaction research on

Indonesian brown coal. In response, NEDO signed in 1994 a

memorandum on cooperative coal liquefaction research with the

Agency for the Assessment and Application of Technology of

Indonesia (BPPT) and began a new round of brown coal liquefaction

technology development that aimed at the realization of commercial

plants for Indonesian brown coal.

Coal liquefaction technology development that has continued since

the Sunshine Project was inaugurated in 1974 has now seen plant

operation concluded in a shift from the research stage to the

commercialization stage. It seems that commercialization will be

enhanced particularly through international cooperation with coal-

producing countries such as China and Indonesia. In China, not

only Japan but also the United States and Germany have embarked

on feasibility studies of location with commercialization in mind.

liquefaction processes has also

taken place since the end of 1980.

2.3 Amalgamation of three coal

liquefaction processes�

With the oil crises as an impetus, the

practice of coal liquefaction technology

development was incorporated for

further promotion into the Sunshine

Project based on Japan’s international

obligations and the need for a large,

constant supply of liquid fuel;

diversification of energy sources and

development of oil-alternative energy

held great significance.

In 1983, NEDO (the New Energy

Development Organization, the

present New Energy and Industrial Technology Development

Organization) assembled the R&D results thus far obtained from the

three bituminous coal liquefaction processes as follows:

(1) Result from Direct Hydrogenation Process: Under any of certain

reaction conditions, the better the catalyst function, the higher the liquid

yield rate becomes.

(2) Result from Solvent Extraction Process: Hydrogen offers liquefaction

under mild conditions.

(3) Result from Solvolysis Liquefaction Process: For priority acquisition

of light oil, it is effective to thicken the circulation solvent.

These three processes were amalgamated on the strength of their

features into the NEDOL Process.

2.4 Bituminous coal liquefaction technology development (NEDOL Process)�

Bituminous coal liquefaction technology development is described in

[3A-2].

2.5 Brown coal liquefaction technology development (BCL Process)�

Brown coal liquefaction technology development is described in [3A-3].

Fig. 2 Review of Coal Liquefaction for Commercialization in China

1) Sadao Wasaka: "Bulletin of The Japan Institute of Energy", 78 (798), 1999

2) "Development of Coal Liquefaction Technology - A Bridge for Commercialization", Nippon Coal Oil Co., Ltd.

3) Haruhiko Yoshida: "Coal Liquefaction Pilot Plant", New Energy and Industrial Technology Development Organization

References

Fig. 1 Basic Philosophy of NEDOL Process

Solvent Extraction System (PDU)

Liquefaction reaction Separation

Solvent hydrogen

Coal

SolventCoal oil

SolventHydrogen

(Catalyst)

450OC,150atm

Ni-Mo catalyst

Ni-Mo catalyst

(Medium to a little heavy)

Coal

Solvent

NEDOL Process

Liquefaction reaction Separation

Solvent hydrogen

Coal

SolventCoal oil

SolventHydrogen

450OC,170atm

Ni-Mo catalyst

(Heavy)

Hydrogen

Direct Hydrogenation System (PDU)

Liquefaction reaction Separation Coal oil

SolventHydrogen

High-performance catalyst (Fe)

450OC,250atm

400OC,150atm

(Ultra-heavy oil)

High-performance catalyst (Fe)

[Referential] EOS Process (U.S.)

Liquefaction reaction SeparationCoal

SolventCoal oil

SolventHydrogen Bottom recycle

450OC,140atm

Solvent,hydrogen

Solvolysis System (PDU)

Degree of dissolution

Liquefaction reactionDeashing SeparationSRC

Coal

SolventCoal oil

SolventHydrogen

450OC150atmAsh

Hydrogen

Ni-Mo catalyst

Solvent hydrogenation technologyhigh-perform

ance catalyst technologySolvent hardening technology

MONGOLIA

TAIWAN

NEIMONGGOL

HEILONGJIANG

JILIN

LIAONING

HEBEI

SHANXI

SHAANXI

NINGXIA HUIZU

HENAN

HUBEI

ANHUI

ZHEJIANG

FUJIAN

JIANGXIHUNAN

GUIZHOU

SICHUAN

GANSU

QINGHAI

GUANGXI ZHUANGZUGUANGDONG

SHANDONG

JIANGSU

Beijing

Harbin

Kunming

MONGOLIA

TAIWAN

NEIMONGGOL

HEILONGJIANG

JILIN

LIAONING

HEBEI

SHANXI

SHAANXI

NINGXIA HUIZU

HENAN

HUBEI

ANHUI

ZHEJIANG

FUJIAN

JIANGXIHUNAN

GUIZHOU

SICHUAN

GANSU

QINGHAI

YUNNANGUANGXI ZHUANGZU

GUANGDONG

SHANDONG

JIANGSU

Beijing

Harbin

Kunming

Shenhua coal U.S. (HTI-USDOE) Japan (NEDO)

Yilan coalJapan (CCUJ-JICA)

Xianfeng coalGermany(Ruhr Kohle-Nordrhein Westfalen State)


45

3A2. Bituminous Coal Liquefaction Technology (NEDOL)


1. Outline of NEDOL Process development�

The conceptual design of a 250 t/d pilot plant (PP) began in

FY1984. Owing to changes in economic conditions, however, the

design of a 150 t/d PP began in FY1988. As a support study to

the pilot plant, the operational study of a 1 t/d process support

unit (PSU) was carried out.

The 1 t/d PSU, constructed in FY1988 at Kimitsu Ironworks of

Nippon Steel Corp., consists of four stages: coal storage and

pretreatment, liquefaction reaction, coal liquefied oil distillation,

and solvent hydrogenation. Over the ten-year period from

FY1989 to FY1998, the joint study team of Nippon Steel Corp.,

Mitsui Coal Liquefaction Co., Ltd., and Nippon Coal Oil Co., Ltd.

conducted operational studies on 9 coal grades under 72 sets of

conditions. Through the 26,949 hours of cumulative coal slurry

operations, the stability and the overall operability of the NEDOL

Process were confirmed, and optimization of the process was

established. Finally, the necessary design data was acquired.

Construction of the 150 t/d PP was launched in 1991 at Kashima

Steelworks of Sumitomo Metal Industries, Ltd. (Kashima City,

Ibaraki), requiring nearly five years for completion. The PP

consists of five main facilities: the coal preliminary treatment unit,

the liquefaction reaction unit, the coal-liquefied oil distillation unit,

the solvent hydrogenation unit, and the hydrogen production unit.

2. Evaluation of NEDOL Process�

Figure 1 shows the progress of coal liquefaction technology since

before World War II, expressed by the relation between the

severity of liquefaction reaction and the yield of coal-liquefied oil

in individual generations. As seen in the figure, the NEDOL

Process is competitive with the processes in Europe and the

United States in terms of technology, economics, and operational

stability, and thus the NEDOL Process is one of the most

advanced processes in the field, reaching a position to shift to

commercialization in the shortest amount of time.

In charge of research and development: New Energy and Industrial Technology Development Organization; Nippon Coal Oil Co., Ltd. [Sumitomo Metal Industries, Ltd.; Idemitsu Kosan Co., Ltd.; Nippon Steel Corp.; Chiyoda Corp.; NKK Corp.; Hitachi Ltd.; Mitsui Coal Liquefaction Co., Ltd.; Mitsui Engineering & Shipbuilding Co., Ltd.; Mitsubishi Heavy Industries, Ltd.; Kobe Steel, Ltd.; Japan Energy Co., Ltd.; Sumitomo Metal Mining Co., Ltd.; Asahi Chemical Industry, Co., Ltd.; Toyota Motor Corp.; Sumitomo Coal Mining Co., Ltd.; Nissan Motor Co., Ltd.; The Japan Steel Works, Ltd.; Yokogawa Electric Corp.; and The Industrial Bank of Japan, Ltd.] Project type: Development of bituminous coal liquefaction technology, and development of NEDOL Process Period: 1983-2000 (18 years)

�

Larg

eS

mal

lY

ield

of c

oal-l

ique

fied

oil

Processes in the ’40s Processes after the Oil Crisis

NEDOL ProcessCC-ITSL Process (U.S.A.)IGOR+ Process (Germany)

First generation Second generation

Third generation

Severity of reaction MildSevere

Fig. 1 Relation between the severity of liquefaction reaction and the yield of coal-liquefied oil

Fig. 1 Relation between the severity of liquefaction reaction and the yield of coal-liquefied oil

Coal preliminary treatment technology

Liquefaction/reaction unit Coal liquefied oil distillation unit

High pressure slurry pump

Slurry tank

Drying/pulverizing

unit

Iron-base catalyst

Coa

l bin

Solvent hydrogenation unit

Slurry mixer

Fuel

Slurry heat exchanger

Let-down valve

Hydrogen compressor

Hydrogen

Circulation gas compressor

Hydrogen

Residue

Stripper

Separator

Solvent hydrogenation

reactor

110kg/cm2G(10.8MPa)

320@C

(Hydrogen-donor solvent) (Heavy distillate)

Fuel

Preheating furnace

Heating furnace

Solvent booster pump

Preheating furnace

Gas

Coal

Naphtha

Kerosene/gas oil distillate

Separator

High temperature separator

Liquefaction reactor (3 units)

Fuel

Vacuum distillation

column

Atmospheric pressure

distillation column

170kg/cm2G(16.7MPa)

450@C


450OC

170kg/cm2 G

Iron-base fine powder catalyst

3wt%(dry coal basis)

40wt%(dry coal basis)

60min

700Nm3/t

85vol%

320OC

110kg/cm2 G

Ni-Mo-Al2O3

1 hr(-1)

500Nm3/t

90vol%


46

3.Features of NEDOL Process�

The NEDOL Process is a coal liquefaction process developed

exclusively in Japan. The process has integrated the advantages

of three bituminous liquefaction processes (Direct Hydrogenation

Process, Solvent Extraction Process, and Solvolysis process),

thus providing superiority in both technology and economics.

The advantages of the NEDOL Process include:

(1) attaining high liquid yield under mild liquefaction reaction

conditions owing to the iron-based fine powder catalyst and to

the hydrogen-donating solvent;

(2) producing coal-liquefied oil rich in light distillate;

(3) assuring high process stability because of the highly reliable

core process stages; and

(4) applicable to a wide range of coal grades, covering from sub-

bituminous coal to low coalification grade bituminous coal.

7. Result of the research and development�

All the acquired data including the PP data, the basic research data,

and the support study data were summarized in a technology

package preparing for practical application. At the

Development and Assessment Committee meeting

for Bituminous Coal Liquefaction Technology in the

Assessment Work Group of the Industrial

Technology Council, held on December 22, 1999, the

NEDOL Process was highly evaluated: "The NEDOL

Process is at the highest technology level in the

world, and has reached the stage where worldwide

diffusion is expected." Thus, the development of coal

liquefaction technology in Japan has already exited

the research and development stage and entered the

practical application stage. Furthermore, the

developed materials and new processes are expected to

significantly influence development in other industries.

4.Typical reaction conditions of the NEDOL Process�

5. Objectives and current progress of the pilot plant

6. Research and development schedule of the NEDOL Process pilot plants

Fig. 3 Total view of NEDOL Process pilot plant (150 t/d)

Catalyst

Catalyst composition Fe (wt%)

S(wt%)

Other(wt%)

Specific surface area (m2/g)

Size of pulverized catalyst [D50]( m)

1. Yield of coal-liquefied oil

2. Slurry concentration

3. Added amount of catalyst

4. Continuous operation time

5. Range of applicable coal grades

Temperature

Pressure

Kind of catalyst

Added amount of catalyst

Slurry concentration

Slurry retention time

Gas/slurry ratio

Hydrogen concentration in recycle gas

For the operation standard coal, 50 wt% or higher yield of light to medium oils, and 54 wt% of higher total yield.

With the operation standard coal, there were attained 51 wt% yield of light to medium oils, and 58 wt% of total yield.

40-50 wt% of coal concentration in slurry. Stable operation was achieved at 50 wt% of coal concentration in slurry.

2-3 wt% (dry-coal basis) of added amount of iron sulfide-base catalyst. Operation was conducted in a range from 1.5 to 3 wt% of added amount of iron sulfide-base catalyst.

1,000 hours or more for the operation standard coal. Continuous operation of 80 days (1,920 hours) was achieved with the operation standard coal.

Three coal grades or more. Operation was conducted with wide range of degree of coalification: namely, Adaro coal, Tanitohalm coal, and Ikejima coal.

Temperature

Pressure

Kind of catalyst

LHSV

Gas/solvent ratio

Hydrogen concentration in recycle gas

48.2

51.0

0.8

6.1

0.7~0.8

Catalyst composition Fe (wt%)

Specific surface area (m2/g)

Micropore volume (ml/g)

Mean micropore size (nm)

Ni-Mo/ Al2O3

190

0.7

14.5

Solvent hydrogenation reactionLiquefaction reaction

Hydrogenation catalyst Liquefaction catalyst

Objective of the development Target Achieved result

~1983(Fiscal year)

1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

250 t/d PP design 150 t/d PP design Construction Operation

Core technology research and support study

1) Sadao Wasaka: "Bulletin of The Japan Institute of Energy", 78 (798), 1999

2) "Development of Coal Liquefaction Technology - A Bridge for Commercialization", Nippon Coal Oil Co., Ltd.

3) Haruhiko Yoshida: "Coal Liquefaction Pilot Plant", New Energy and Industrial Technology Development Organization

References

Central control building

Liquefaction reaction unit

Coal-liquefied oil distillation unit

Storage unit

Fuel unit

Solvent hydrogenation unit

Coal preliminary treatment unit

Hydrogen production unit


47

Fig.1 Flowchart of BCL

3A3. Brown Coal Liquefaction Technology (BCL)



Economically viable global coal reserves are expected to total

about one trillion tons, about half of which is comprised of low-

grade coal such as sub-bituminous coal and brown coal. Coal

has a larger ratio of reserves to production (R/P) than that of oil

and natural gas. For full-scale effective utilization of coal,

however, the effective use of low-grade coal is critical. Low-

grade coal contains a large amount of water but has an

autoignition property in a dry state compared with bituminous

coal and other higher grade coals. Consequently, brown coal

liquefaction technology development progressed aiming to

contribute to a stable supply of energy in Japan by converting the

difficult-to-use low-grade coal into an easy-handling and useful

product, or by producing clean transportation fuels such as

gasoline and kerosene from the low-grade coal.

As shown in the figure, the BCL process has four stages: the slurry

dewatering stage where the water is efficiently removed from low-

grade coal; the liquefaction stage where liquefied oil production

yield is increased by using a highly active limonite catalyst and the

bottoms recycling technology; the simultaneous hydrogenation

stage where the heteroatoms (sulfur-laden compounds, nitrogen-

laden compounds, etc.) in the coal-liquefied oil are removed to

obtain high quality gasoline, kerosene, and other light fractions;

and the solvent deashing stage where the ash in coal and the

added catalysts are efficiently discharged from the process

system.

In Asian countries, economic growth steadily increases energy

demand, and countries possessing low-grade coal resources, such

as Indonesia, anticipate commercialization of the technology.

Liquefaction stage

Hydrogen

Slurry dewatering stage

Recycle gas

Recycle gas

Coal (Raw brown coal)

Water

Evaporator

Reactor

Preheater

Slurry charge pump

Catalyst supply unit

CLB recycle

Solvent recycle

DAO (deashed heavy oil) recycle

In-line hydrotreatment stage

Sulfur recovery unit Sulfur

Off gas purification unit Product gas

(Fuel gas)

Hydrogenated light oil

Distillation column

Hydrogenated medium oil

Fixed bed hydrogenation reactor

Solvent deashing stage

Settler

CLB (heavy oil) separator

Sludge

CLB (Boiler fuel)

In charge of research and development: New Energy and Industrial Technology Development Organization; Kobe Steel, Ltd.; Nissho Iwai Corp.; Mitsubishi Chemical Corp.; Cosmo Oil Co., Ltd.; Idemitsu Kosan Co., Ltd.; and Nippon Brown Coal Liquefaction Co., Ltd.Project type: Development of Brown Coal Liquefaction Technology; Development of Liquefaction Basic Technology; Coal Liquefaction International Cooperation Project; and other projectsPeriod: 1981-2002 (21 years)



48


On the basis of a memorandum on cooperative coal liquefaction

research between the Agency for the Assessment and

Application of Technology of Indonesia and New Energy and

Industrial Technology Development Organization, the study team

carried out surveys and liquefaction tests of the low-grade coal in

Indonesia beginning in 1994, in addition to screening of

candidate coals for liquefaction. Furthermore, the team

endeavored to increase the technical abilities of the Indonesian

engineers through instruction and supply of liquefaction testing

equipment.

In 1999, the study team selected three candidate sites for the

liquefaction plant in Indonesia, and carried out a feasibility study

on coal liquefaction, including an economic evaluation. The

feasibility study revealed that coal liquefaction would be

economically feasible only if the price of oil did not decrease.


Supported by steady economy growth, Asian countries exhibit

rapidly increasing energy demand. Although currently a net oil-

exporting country, Indonesia is expected to become a net oil-

importing country by around 2010. Since the stable supply of

energy from Asian countries to Japan significantly contributes to

the energy security of Japan, expectations are high for the

practical application of brown coal liquefaction technology

utilizing unexploited low-grade coal. From a medium-term

viewpoint, the possibility of practical application of the technology

is large.

1) Shunichi Yanai and Takuo Shigehisa: CCT Journal, vol.7, p 29 (2003)

�2) Report of the Result of the International Coal Liquefaction Cooperation Project

� (Cooperative Study of Development of Low Grade Coal Liquefaction Technology) (2003)

References

A pilot plant (refer to the photograph) study

conducted under the governmental cooperation of

Japan and Australia investigated the subjects

listed below.

(1) Achieving high liquefied oil production yield:

50% or more

(2) Achieving long-term continuous operation:

1,000 hours or more

(3) Achieving high deashing performance: 1,000

ppm or less

(4) Establishing a new slurry dewatering process

Through four years of operation and study (1987-

1990), all of the above targets were achieved.

Furthermore, scale-up data necessary to

construct commercial liquefaction plants and

expertise on plant operation was obtained

through pilot plant operation.

During the study period, (the 1990s), however, a

state of low oil prices and stable oil supplies existed worldwide

owing to a stable international oil supply and demand situation.

Thus, further improvements in the economics of the coal

liquefaction process were requested, while cleaner liquefied oil

was demanded owing to increased environmental concerns.

Accordingly, the study team constructed a bench-scale plant (0.1

t/d) in the Takasago Works of Kobe Steel, Ltd. to conduct a study

for improving the process. The study developed: a limonite

catalyst which has extremely high activity compared with existing

liquefaction catalysts, and which has superior handling properties

such as crushing property; a method to maintain catalytic activity

through the bottoms recycling technology; a simultaneous

hydrogenation technology which significantly improves the quality

of coal-liquefied oil; and various improvements for increasing

operational reliability. Through the development work, the study

established the improved BCL process (Improved Brown Coal

Liquefaction Process, refer to the flowchart on the preceding

page) that significantly improves the economics, reliability, and

environmental compatibility of the brown coal liquefaction

process.

Fig.2 50t/d Pilot plant (Australia)

2.Development objectives and technology to be developed


49

3A4. Dimethylether Production Technology (DME)



Dimethylether (DME) is a clean energy source of low

environmental load, generating no sulfur oxide or soot during

combustion. Owing to the non-toxicity and easy liquefaction

properties, DME is easy in handling, thus it can be used as

domestic-sector fuel (substitute for LPG), transportation fuel

(diesel vehicle, fuel cell automobile), power plant fuel(thermal

plant, cogeneration plant, fuel cell), and raw material for chemical

products.

Currently DME is produced by dehydration of methanol at

amount of about 10 thousand tons a year in Japan, and 150

thousand tons a year in the world. The main use of DME is spray

propellant. If the supply of DME is available in large amount at

low price, DME is expected to be used as fuel in wide fields

owing to the above-described superior properties.


The object of the study is the development of direct synthesis

process of DME from syngas (mixed gas of H2 and CO),

(reaction (1)).

The DME production through the dehydration of methanol,

(reaction (3)), is the existing technology. The plant scale under

actual operation, however, is rather small, and the scale up is an

issue to produce DME commercially for fuel service. In addition,

the equilibrium conversion of the methanol synthesis reaction (2)

is relatively small as show in Fig.1.

On the other hand, in the direct DME synthesis reaction (1)

because the limitation of equilibrium of methanol synthesis is

avoidable the conversion is higher than that of methanol

synthesis.

The reaction formulae relating to the direct DME synthesis are

given below. The equilibrium conversion of methanol synthesis

and of direct DME synthesis is given in Fig. 1.

Since the direct synthesis gives maximum conversion at

H2/CO=1 of the syngas composition, the process is suitable for

the syngas produced from coal gasification (H2/CO=0.5-1). The

targets of the development study include the following.

<1.DME production rate: 100 ton/d or more, Syngas total

conversion: 95% or more, DME selectivity: 90% or more, DME

purity: 99% or more

2. Establishing scale up technology

3. Optimization of total system

4. Establishing stable plant operation >

(1) 3CO+3H2 CH3OCH3+CO2

(2) CO+2H2 CH3OH(3) 2CH3OH CH3OCH3+H2O

Fig. 1 Equilibrium conversion (280OC, 5Mpa)

40

20

60

80

100

0.0 0.5

H2/CO ratio [-]

H2+

CO

con

vers

ion

[%]

(2) CO + 2H2 CH3OH

(1) 3CO + 3H2 CH3OCH3 + CO2

1.0 1.5 2.0 2.5 3.0

In charge of research and development:DME Development Co., Ltd. (The company was established in 2001 in collaboration of following-listed

ten companies aiming to establish the technology of direct synthesis of DME.), JFE Holdings Co., Ltd.; Nippon Sanso Corp.; Toyota Tsusho Corp.; Hitachi Ltd.; Marubeni Corp.; Idemitsu Kosan Co., Ltd.; INPEX Corporation; TOTAL S.A.(France); LNG Japan Co., Ltd.; and Japan Petroleum Exploration Co., Ltd.(JAPEX)Project type: National Grant project of "Development of Technology for Environmental Load Reducing Fuel Conversion" of the Agency of Natural Resources and Energy of the Ministry of Economy, Trade and IndustryPeriod: 2002-2006 (5 years)



50


DME is already utilized as a fuel at inland area of China in small

scale. In Japan, activities toward the practical application of DME

as fuel are in progress at: DME International Co., Ltd. which was

established by the same ten companies of DME Development

Co., Ltd. aiming at the study for Commercialization of DME;

Japan DME Co., Ltd. which was established by four companies,

namely, Mitsubishi Gas Chemical Co., Inc., Mitsubishi Heavy

Industries, Ltd., JGC, and Itochu Corp.; Mitsui & Co., Ltd. and

Toyo Engineering Corp.; (the last two adopted the methanol

dehydration process). These activities aim to supply DME

product in 2006. All of them plan to use natural gas as the raw

material, because natural gas requires small initial investment. In

the future, however, they are supposed to switch the raw material

to coal which is larger in reserves quantity than natural gas.

In natural gas case, the CO2 obtained from CO2 separation

column is returned to syngas generation furnace, but the same is

released to atmosphere in coal case. When the CO2 storage

technology in long term is established in future, the coal based

process can provide purified CO2 without any additional facilities.

Also in western world, DME draws attention in wide fields as a

new fuel. They however, expect mainly to use in diesel vehicles

to fully utilize the advantageous characteristic of no-generation of

soot.

1) Tsunao Kamijo et al.: Lecture papers of The 8th Coal Utilization Technology Congress, Tokyo 1998, pp.194-205

2) Yotaro Ono et al.: Preprint for the lectures of the 30th Petroleum and Petrochemical Discussion Meeting, Tokyo 2000, pp.26-29

3) Yotaro Ono: Japan DME Forum Workshop 2002, Tokyo, pp.113-122

References


The development of direct synthesis process has been led by

JFE (ex-NKK). The first step is the search of direct synthesis

catalyst. The second step is the small bench plant (5 kg/d). The

third step is the pilot plant (5 ton/d) 1)2) constructed with the aid of

the Ministry of Economy, Trade and Industry. The fourth step is

the demonstration plant (as large as 100 ton/d) constructed also

with the aid of the Ministry of Economy, Trade and Industry. The

construction of demonstration plant finished in November 2003,

and the operation is scheduled to start at the end of 2003 to

conduct five runs of long period continuous operations (2 to 3

months) until 20063).

Photo 1 5 ton/d pilot plant Photo 2 100 ton/d demonstration plant

Fig. 2 Typical process flow diagram of DME direct synthesis plant from coal or natural gas

Steam

Oxygen

Coal

Coal mine methane

Natural gas

CO2 CO2

Synthesis gas generation furnace Gas purification column DME synthesis reactor CO2 separation column

Liquid/gas separator

Reaction condition250~280OC3~7Mpa

DME purification column

Non-reacted gas

Methanol

Purge gas

CO,CO2,H2

DME

Multi-Purpose Coal Utilization Technologies (Pyrolysis Technologies)

51

3B1. Multi-Purpose Coal Conversion Technology (CPX)


1.Technological features�

In an attempt to further expand versatile utilization of coal, this

project is intended to develop a multi-purpose coal conversion

technology excellent in efficiency, economy, and environment-

friendliness, mainly for the purpose of manufacturing medium-

calorie gas as industrial fuel and liquid products as raw materials

for chemicals.

The features of this process are as follows:

1. Moderate operational conditions

- The pyrolysis reactor works at a temperature of as low as 600-

950OC.

- The reaction pressure of lower than 1Mpa is much lower than

several to tens of Mpa at which the coal liquefaction and hydro-

gasification processes operate.

2. High overall thermal efficiency

- Flash pyrolysis of coal is combined with partial recycle of

generated char to gasify more char, thereby improving the

thermal efficiency of the process.

3. Workable with multiple kinds of coal

- The dependence on cheaper classes of coal from sub-

bituminous to highly volatile bituminous coal for the main material

enables gas/tar to be obtained in large quantities.

4. Efficient separation of coal ash

- Coal ash is discharged from the gasifier as molten slag and

then granulated with water.

5. Diversified utilization of products available

- Among products, gas can be used as industrial fuel, liquid (light

oil/tar), as raw materials for chemicals, solid char, as fuel or a

reducer, and slag, as an ingredient of cement.

- The heating value of gas produced from the process is as high

as about 3,500kcal/Nm3.

- The yield of gas and liquid (light oil/tar) combined is 70% or

more of coal input.

6. Controllable yield of products

- A change in pyrolysis temperature (600-950OC) or coal kind

allows product yields to be correspondingly changed.

Fig.1 Process Flow Sheet

*Coal Flash Pyrolysis Process: CPX stands for Coal Pyrolysis suffixed with X meaning diversified products.

In charge of research and development: Center for Coal Utilization, Japan; Nippon Steel Corporation; NKK Corporation; Kawasaki Steel Corporation; Sumitomo Metal Industries, Ltd.; Kobe Steel Ltd.; Ube Industries, Ltd.; Idemitsu Kosan Co., Ltd.; Nippon Steel Chemical Co., Ltd.Project type: Subsidized coal production/utilization technology promotionPeriod: 1996-2000 (5 years)

Coal

Crushing/drying

Pyrolysis

reactor

SteamChar gasifier

Slag

Heat recovery

Cyclone

Scrubber

Char hopper

Char heat recovery

Tar cooler

Gas purification Gas

Decanter

Separator Tar

Char



52

1) Hiroyuki Kozuru et al.: Advanced Clean Coal Technology Int’l Symposium (2001)

2) Masami Onoda et al.: 10th Annual Conference on Clean Coal Technology abstracts (2000)

3) Shigeru Hashimoto et al.: Pittsburgh Coal Conference (2000)

References

2.Summary of technology�

This process is characterized by higher overall thermal efficiency

achieved with a compact low-pressure char/oxygen gasification

system, which combines flash pyrolysis of coal and partial

recycle of pyrolysis product char to use sensible heat of char

gasification product gas as a heat source for flash

heating/pyrolysis reaction of pulverized coal (Fig.1). The

entrained-bed coal flash pyrolysis has been developed as a

process which not only produces more high value-added gas and

liquid (tar and oil) possessing a coke oven gas (COG)-equivalent

heating value but also supplies heat necessary for pyrolysis.

Pulverized and dried coal (of about 50 m in grain size) is blown

into the pyrolysis reactor and mixed with hot gas at 600-950OC

and several atm, with 2 seconds as its reaction time, to be flash-

heated/pyrolyzed. In terms of heat necessary for pyrolysis

reaction, part of pyrolysis product solid char is recycled to the hot

gas generation section (char gasifier) to be partially oxidized by

oxygen and steam, thus allowing an about 1,500-1,600OC stream

of gas mainly composed of CO and H2 to generate so that

sensible heat of the gas is used for the supply of such heat. The

pyrolysis reactor employs an up-flow system where the hot gas

generated at this gasifier is fed from the lower part of the reactor

and, after pyrolysis coal is mixed, leaves the system at the

reactor’s upper part together with pyrolysis products. Part of a

solid product (char) separated at the cyclone is recycled to the

char gasifier and the remaining is offered as a product after heat

recovery. Heat is recovered from the gas containing pyrolysis

products until it cools down to about 350OC through indirect heat

exchange with thermal oil while tar passes the venture

scrubber/tar cooler to be recovered. Pyrolysis gas is made

available for use as industrial-purpose fuel gas after purification

such as through light oil (BTX) recovery and desulfurization.

At the pilot plant (Photo 1) built within Yawata Works of Nippon

Steel Corp., tests were conducted mainly with a view to the

evaluation/verification of process component/total system

technologies to establish the technological basis for

commercialization as well as obtain data which would help

design an actual plant (1,000t/d) and evaluate its economy. In

two years from 1999, it was test-run 10 times in all, achieving a

maximum 210-hour stable continuous operation. During the

time, the aforementioned features were verified, assuring the

controllability of products at a pyrolysis temperature (Fig.2)

before the completion of process data taking.

Photo 1 Full View of Pilot PlantFig. 2 Relationship between Pyrolysis Product Yield and Pyrolysis Temperature

PDU:7t/d test equipment

53�

3B2. Coal Flash Partial Hydropyrolysis Technology


1.Objective of technology�

Clean Coal Technology-related technology development having a

perspective of a single industry in pursuit of a single product is

reaching its limits in terms of efficiency and economy, calling the

necessity to develop such innovative technologies as could

completely change what energy and material production should

be.

Coal Flash Partial Hydopyrolysis Technology is a technology

which causes rapid reaction to pulverized coal under high

pressure (2-3Mpa) and in a moderate hydrogen atmosphere to

highly efficiently obtain, from one reactor, synthetic gas easy to

be evolved such as into Integrated Gasification Combined-Cycle

(IGCC) power generation, indirect liquefaction (GTL), and

chemicals while co-producing light oil as chemicals and fuel.

The realization of a coal-based cross-industrial composite project

(led by electric power/chemistry/steel) with this technology as its

core will hopefully bring a dramatic improvement to total energy

utilization efficiency.

Fig. 1 Process Flow


Fig. 1 shows a total process flow of this technology. At the partial

oxidation section of a coal flash partial hydropyrolsyis reactor,

pulverized coal and recycled char are gasified with oxygen and

steam at a pressure of 2-3MPa and at a temperature of 1,500-

1,600OC to give hot gas mainly composed of CO and H2. At the

reforming section directly connected through a throat to the

partial oxidation section, pulverized coal is injected together with

recycled H2 into the hot gas stream from the partial oxidation

section to complete the reforming reaction (partial hydropyrolysis)

in a moment under the condition of 2-3MPa in pressure, 700-

900OC in temperature, and about 30-50% in hydrogen

concentration (H2 in hot gas and recycle H2 combined). At that

time, hot gas from the partial oxidation section also functions as a

source of the reaction heat required at the reforming section. At

the reforming section, a hydrogenation reaction adds H2 to

primary pyrolysis, such as tar released from pulverized coal,

changing heavy tar-like matter to light oil. The gas, light oil, and

char produced at the partial hydropyrolysis reactor follow a

process where, after char separation at the cyclone and

subsequent sensible heat recovery, synthetic gas (syngas)

should be formed by way of oil recovery, desulfurization, and

other gas purification processes. Part of syngas is converted into

In charge of research and development: The Center for Coal Utilization, Japan; the New Energy and Industrial Technology Development Organization; the National Institute of Advanced Industrial Science and Technology; Nippon Steel Corporation; Babcook Hitachi K.K.; Mitsubishi Chemical CorporationProject type: Subsidized coal production/utilization technology promotion projectPeriod:1. Coal utilization next-generation technology development survey/1996 through1999 (4 years)2. Coal utilization commercialization technology development/2003 through 2008 (6 years)

Decarboxylation Shift conversion to H2

Reforming section

H2 concentration 30-50%

Partial hydropyrolysis reactor

Hot gas

Partial oxidation section

CoalCoal

Steam

Slag

Char

Heat recovery

Gas purification

Syngas

Coal reforming reaction

Heat

Heat

Gas

Light oil

Light oil

Chemicals

Chemicals

IGCC fuel

GTL fuel City gas

Fuel for power generation

Part2 Outline of CCTMulti-Purpose Coal Utilization Technologies (Pyrolysis Technologies)

Verification of the reaction in the partial hydropyrolysis reactor/

establishment of reactor control technology

Pilot plant test

Design/production/construction works

Studies by testing

Studies by disassembly

Assistant studies

- Quantification of partial hydropyrolysis reactor reaction- Establishment of reactor conditions for optimum transition zone formation- Establishment of high-efficiency gasification (partial oxidation section) operational conditions

Development of process/factor technologies- Establishment of technology to separate/recover char from gas- Establishment of technology to recover heat from gas co-existent with oil

Total system evaluation, etc.- Establishment of long-hour continuous operation technology- Establishment of a scale-up approach for demonstration unit design

Technology to be developed R&D items


54

3.Progress status of development�

1) Basic partial hydropyrolysis test (1996 through 1999, 1kg/day)

Using a small-scale test unit, the pyrolysis behavior of coal under

target conditions of this technology was reviewed, confirming that

the hydropyrolysis of primary tar released from flash

heating/pyrolysis reaction of coal successfully proceeded.

2) Process development unit (PDU) test (2000 through 2003,

1t/day *NSC in-house research)

Using a reforming/partial oxidation-integrated PDU test unit, the

basic performance of a partial hydropyrolysis reactor as the core

of this technology was evaluated, clarifying the reaction in the reactor.

3) Pilot plant test (2003 through 2008, 20t/day)

Tests are conducted, using a pilot plant having its thermally self-

supportable reactor together with other ancillary process units, to

have forecasts for a demonstration unit (up to 1,000t/day) as the

next step.

1) H. Shimoda et al, 10th Annual Conference on Clean Coal Technology lecture collection, p296, 2000

2) H. Yabe et al, 2nd Japan-Australia Coal Research Workshop Proceedings, p257, 2002

References

Table 1 Development Subjects for Pilot Plant Tests

2003 2004 2005 2006 2007 2008

Table 2 Development Schedule

H2-rich gas in the course of shift reaction and decarboxylation

(CO2 recovery) and, after pre-heated via heat exchange, recycled

to the partial hydropyrolysis reactor’s reforming section. A final

syngas product is characterized by its main composition of H2,

CO, and CH4 as well as high hydrogen contents at H2/CO 1 and

used as source gas of IGCC, GTL, and chemicals. Light oil is

mainly composed of aromatic compounds with 1-2 rings such as

benzene and naphthalene, finding its application as chemicals or

fuel for power generation.

This technology is roughly featured as follow:

1. High-efficiency: The sensible heat of hot gas generated at the

partial oxidation section is effectively used as a source of heat

required at the reforming section, providing high energy

conversion efficiency.

2. Flexible productivity: The reforming section temperature as

well as the amount of hydrogen injected can be controlled so as

to freely change the gas/oil composition and output ratio, thereby

flexibly responding to consumers’ needs.

3. Economy: For the purpose of syngas production, gas

production cost may be reduced through its deduction by co-

produced high value-added oil.

Multi-Purpose Coal Utilization Technologies (Powdering, Liquefaction, and Common Use Technologies)

55

3C1. Coal Cartridge System (CCS)


1.Outline of system�

The CCS (Coal Cartridge System) is a system where, on behalf

of medium-/small-lot consumers using several thousands of tons

of coal a year, for whom it is difficult to import overseas coal

constantly for themselves, overseas coal is collectively imported

and blended into qualities suitable for each such consumer to be

supplied as pulverized coal.

This technology was subjected, under a 3-year program starting

from 1985, to demonstration tests at manufacture/supply and

combustion bases, in an attempt to establish the reliability of

CCS as well as coal blending and suitable quality requirements

for CCS standard coal production. As a result, the first Japanese

CCS center (with a capacity to produce 200 thousand tons a

year) was built in 1991 and then 2 CCS coal-dedicated boilers

started operation.

(Table 1) Attributes of CCS Coal in General

BrandRaw coal for mixtureTotal moisture Wt%Heating value kcal/kg Moisture Wt% Ash Wt% Volatiles Wt% Fixed carbon Wt%Fuel ratio Carbon Wt% Hydrogen Wt% Nitrogen Wt% Oxygen Wt% Sulfur Wt%Total sulfur Wt%Grain size -200mest

Referential control

AR*

drydrydrydry

dafdafdafdafdafdrydry

A3 kinds

2.96490 0.0 12.1 39.6 48.3 1.22

80.30 5.80 1.60 11.80 0.48 0.45 84.5

B3 kinds

2.86480

0.0 12.4 39.5 48.1 1.22

80.00 5.801.50

12.400.470.4378.9

C2 kinds

2.764900.0

12.135.650.31.41

82.005.901.50

10.500.450.41

83.50

Pro

xim

ate

ana

lysi

sU

ltim

ate

anal

ysis

(Fig.1) CCS Coal Production/Supply Facility

4.Process flow�

(Fig.1) shows a flow sheet and system outline of the CCS coal

production/supply facility.

2.Characteristics of system�

Common systems of pulverized coal firing, before burning the coal

stored at its stockyard, pulverize it with a mill for the supply to a

boiler, but in CCS, after coal is pulverized at a production/supply

facility, all processes are to be completed within a closed system

of gaseous-phase carriage, from loading onto tank lorries to

deacquisition to consumers’ coal silos and then supply to boilers.

This not only eliminates the problem of coal dust scattering,

thereby keeping the environment clean, but also enables smooth

operation to be realized through easier control of powder flows

and, therefore, fluctuations in boiler loads.

In behalf of consumers, this also advantageously requires no mill

installation, dispenses with a coal yard since coal can be stored in a

silo, and lessens equipment investment due to the compact equipment

configuration, thus leading to labor saving and the better environment.

CCS is, as mentioned above, a coal utilization system of improved

coal handling with a closed powder carriage system of pulverized coal.

3.Technical data�

Attributes of CCS coal in general are shown in (Table 1)

Outline of equipment

Con

veyo

r

Raw coal hopper Magnetic separator

Raw coal bunker

Volumetric coal feeder

Mill supply hopper

Table feeder

Chain conveyor

Pulverizer

Seal gas blower

Industrial water

Cooling tower

Gas cooler

Air heaterFuel gas

Kerosene

Fuel air blower

Pulverized coal collection bag filter

Screw conveyor

Product silo

Product silo

Product silo

Product silo

Truck scale

Recycle gas blowerRecycle gas line

Nitrogen generator

tank

tank

1 Raw coal hopper 20m3x1 unit2 Raw coal bunker 400m3/Hx2 units3 Pulverizer 25t/Hx2 units

4 Bag filter 67,500Nm3/Hx1 unit5 Product silo 680m3x4 units6 Truck scale 4 units7 Nitrogen generator 350Nm3x1 unit


Reception/storage of feed coal

Smashing

Enhancement of mixing

CWM storage

CWM shipment

Hot wet smashing

Coal smashing and mixingwith water/additives to bedone within a pulverizer


56

3C2. Coal Slurry Production Technology


1.Outline of coal slurry�

Since coal is a solid material with some problem, requiring more

complex handling than a fluid does, environmental measures

against dust, and spacious land for a coal yard, its slurry form

has been noted as a means to make heavy oil-comparative,

clean use of coal. Coal slurry fuel is found as COM (coal oil

mixture) prepared by adding heavy oil to coal to give slurry, aside

from CWM (coal water mixture), a mixture of coal and water.

COM, a combination of coal and heavy oil convenient for burning,

was earlier than CWM to be technically reviewed but failed to

prevail after all, rather bottlenecked by the necessity of heavy oil.

CWM is a mixture of water and coal, raising no problem of

spontaneous firing or dust scattering and can advantageously be

handled as an easy-to-treat liquid. Conventional coal slurry using

no additive can be piped but, due to its water contents of about

50%, is poor in long-run stability, requiring dehydration before firing.

High-concentration CWM can now, as a result of studies on the

particle size distribution of coal and a dispersant and other additives

development, be kept fluid as well as stable even if less water is

added and, therefore, directly burnt without being de-watered. Only

a slight amount of additives added realize stable coal-water slurry in

which coal particle of a certain size distribution are uniformly

dispersed with their weight concentration of about 70%.

3.Manufacturing process of high-concentration CWM�

Production of high-concentration

CWM can be achieved by

pulverizng coal into a particle

size distribution suitable for

CWM, selecting correct additives

(a dispersant and stabilizer), and

appropriately blending coal,

water, and additives to

manufacture high-concentration,

low-viscosity, high-stability, and

good-quality CWM. A block flow

of CWM manufacturing process

is shown in Fig.1.

2.Characteristics of high-concentration CWM�

Typical characteristics of high-concentration CWM (Chinese coal

CWM) are shown in (Table1) below.

1) Coal type

As a general trend, high-carbonization, low-inherent moisture

(about 5% or less in approximate analysis), and less-oxygen

content (about 8% or less in ultimate analysis) coal is suitable for

high-concentration CWM.

2) Additives

Additives consist of dispersants and stabilizers. A dispersant

functions to disperse coal particles into slurry, using electrostatic

repulsion effects or steric repulsion effects and sodium sulfonate of

naphthalene, polystyrene, polymethacrylate, polyolefine, and the like

is used here. Additives including CMC and xanthan gum are used to

prevent coal particles in slurry from settling for stabilization.

3) Particle size distribution

For higher concentration/stability of CWM, pulverized coal sizes

should preferably be distributed over a wide range rather than

sharply distributed. Ordinary particle sizes used are roughly as

shown in (Table 2).

4) Rheological characteristics

CWM’s fluidity has characteristics of a non-Newtonian fluid but

can be construed as a near-Bingham fluid’s. The fluidity

characteristics also changes, depending upon, such as the coal

kind, concentration, additive, and flow state. The apparent

viscosity is roughly 1,000mPa-s (at room temperature and shear

speed of 100/s).

5) Heating value

The heating value depends upon that of coal used. An average

lower heating value is 4,600-4,800kcal/kg.

(Table 1) Characteristics of High-Concentration CWM

Coal concentration (wt%)

Higher heating value (kcal/kg)

Lower heating value (kcal/kg)

Apparent consistency (mPa-s)

Specific gravity(-)

Ash content (wt%)

Sulfur content (wt%)

Grains of 200 mesh or less (%)

68~70

5,000~5,200

4,600~4,800

1,000

1.25

6.0

0.2

80~85

(Table 2) Grain Size Distribution of High-Concentration CWM

Maximum grain size

Average grain size

Grains of 74 m or less

Fine grains of several micrometers or less

150~500 m

10~20 m

80% or more

Around 10%

Cold wet smashing

De-watering

Smashed coal/water/additives mixing Smashed coal/water/additives mixing

Dry smashing

(Fig.1) CWM Manufacturing Process Coal Water Mixture (CWM)


57

3C3. Briquette Production Technology

Outline of the technology

1.Background�

The global warming issue caused by CO2 and other substances

has become world concern in recent years. To protect forestry

resource as a major absorbent of CO2, control of ever-increasing

deforestation along with the increase in consumption of wood fuel

such as firewood and charcoal is an urgent issue. Thus, the

development of substitute fuel for charcoal is emphasized.

To this point, the briquette production technology is an

environmental countermeasure technology, or a clean coal

technology, providing the stable supply of briquettes to contribute

to the prevention of flood damage and the conservation of

forestry resource.

Fig. 1 Process flow of briquette production

Fig. 2 Cross sectional view of carbonization furnace

2.Carbonized briquettes�

(1)Process outline

Process for producing briquettes by coal carbonization has the

carbonization stage and the forming stage. Figure 1 shows the

basic process flow.

The carbonization stage has the internal heating low temperature

fluidized bed carbonization furnace (about 450OC of carbonization

temperature) to produce smokeless semicoke containing about

20% of volatile matter. The carbonization furnace has a simple

structure having no perforated plate and agitator so that the

operation and the maintenance of the furnace are easy.

In the forming stage, the smokeless semicoke and auxiliary raw

materials (hydrated lime and clay) are thoroughly mixed at a

predetermined mixing ratio. After pulverizing, the mixture is

blended with a caking additive while adding water to adjust the

water content of the mixture. The mixture is kneaded to

uniformize the distribution of caking additive, and to increase the

viscosity to attain an easy-forming condition. Then the mixture is

introduced to the molding machine to prepare briquettes. The

briquettes are dried and cooled.

(2)Carbonization stage

The raw material coal (10% or lower surface water content, 5-50

mm of particle size) is preliminarily dried in the rotary drier. The

gas leaving the drier passes through multi-cyclone to remove

dust before venting to atmosphere. Figure 2 shows the cross

sectional view of the internal heating low temperature fluidized

bed carbonization furnace which performs most efficient

carbonization of semicoke while retaining about 20% of volatile

matter in the semicoke.

The preliminarily dried

raw material coal is

charged to the middle

section of the furnace,

and is subjected to

fluidization carbonization.

The product semicoke is

taken out from top of the

furnace together with the

carbonization gas. The

semicoke is separated

from the carbonization

gas by the primary cyclone

and the secondary cyclone.

After cooled, the semicoke

is transferred to the

stockyard, and the carbonization gas is supplied to the

combustion furnace lined with refractory, where the carbonization

gas is mixed with air to combust. The generated hot gas is

introduced to the raw material coal drier and to the succeeding

briquette drier to use as the drying heat source of preliminary

heating of the raw material coal and the drying heat source of the

formed oval briquettes.

(3)Forming stage

The semicoke (Coalite) produced in the carbonization stage is

the briquette raw material containing adequate amount of volatile

matter, small amount of ash and sulfur, and emitting no smoke

and no odor. The semicoke as the main raw material is mixed

with hydrated lime (sulfur fixing agent), clay (assistant for

forming), and a caking additive.

Raw Coal

Drying

Crushing

Coalite

Cyclon

Desulfurizer

Binder

Water

MixingKneading

Briquetting

Drying

Briquette

Carbonizing



58

Fig. 3 Basic flow of bio-briquette production

3.Bio-briquettes�

Bio-briquettes are a kind of solid fuels, prepared by blending coal

with 10-25% of vegetable matter (biomass) such as wood

bagasse (strained lees of sugar cane), straws, and haulms of

corn, further with desulfurizing agent (Ca(OH)2) by an amount

corresponding to the sulfur content in the coal. Owing to the high

pressure briquetting (1-3 t/cm2), the coal particles and the fibrous

vegetable matter in the bio-briquette strongly interwind and

adhere to each other. As a result, they do not separate from

each other during combustion, thus attaining combined

combustion of the vegetable matter having low ignition

temperature and the coal. The combined combustion gives

favorable ignition and fuel properties, emits very small amount of

dust and soot, and generates sandy combustion ash to leave no

clinker. Furthermore, since the desulfurizing agent also adheres

to the coal particles, the agent effectively reacts with the sulfur in

the coal to fix about 60-80% of the sulfur into the ash.

Applicable coal grades are many, including bituminous coal,

subbituminous coal, and brown coal. In particular, the bio-briquettes

utilizing low grade coal containing large amount of ash and having

low calorific value gives large effect of coal-cleaning, thus the bio-

briquette technology is an effective technology to produce clean fuel

for household heaters and industrial small boilers.

(1)Production flow of bio-briquettes

Figure 3 shows the basic flow of bio-briquette production. The

coal and the biomass as the raw materials are pulverized to

about 3 mm or smaller size, which are then dried. The dried

mixture is further mixed with a desulfurizing agent (Ca(OH)2).

The mixture is formed by compression molding in the high

pressure briquetting machine. Powder coal may be applied

without subjected to pulverization. A small amount of binder may

be added to some coal grades.

The production process does not contain high temperature

operation, and has a structure centering on the dry high pressure

briquetting machine. The process is simple facility flow which is

safe and which does not require skilled operational technique.

Owing to the high pressure briquetting method, the coal particles

and the biomass strongly interwind and adhere to each other,

thus the process produces rigid formed coal which does not

separate their components during combustion.

(2)Bio-briquette characteristics

1. Compared with the coal direct combustion, the bio-briquette

combustion decreases the generation of dust and soot by one fifth

to one tenth. The coal direct combustion gives increased

generation of dust and soot because the volatile matter released in

the low temperature region (200-400OC) does not completely

combust. To the contrary, bio-briquettes combust simultaneously

the low ignition point biomass which entered between coal particles

with the coal, which assures the combustion of volatile matter

released in the low temperature coal combustion region. As a

result, the amount of generated dust and soot significantly reduces.

2. The bio-briquettes prepared by adding 15-20% of biomass to

coal gives significantly short ignition time to improve the ignition

property. In addition, the bio-briquettes have low expansion

caking property so that the aeration between briquettes is

secured during continuous combustion in a fireplace, giving

favorable combustion characteristic.

Consequently, the bio-briquettes have superior combustion-

sustaining property, and do not die out in a fireplace or other heater

even when air rate is decreased to slow down the combustion rate,

which makes the adjustment of combustion rate easy.

3. Since fibrous biomass enters between coal particles, there is

no fear of clinker-lump formation during combustion caused by

adhesion of fused ash in coal, thus the ash falls in sandy form

through grate. Therefore, aeration is secured to stabilize the

combustion state. Furthermore, since no clinker is formed, ash

contains very small amount of unburnt coal.

4. The bio-briquettes are formed under high compressive force.

Accordingly, the desulfurizing agent and the coal particles strongly

adhere to each other, and they effectively react during combustion.

With the addition of desulfurizing agent at about 1.2-2 of Ca/S

ratio, 60-80% of the sulfur in coal is fixed in the ash.

Photo 1 Formed briquettes

To attain uniform composition and improved formability, the mixed

raw material is fully kneaded. Forming of the mixture is carried

out using the roll molding machine at normal temperature and

under about 1,000 kg/cm (300-500 kg/cm2) of line pressure.

Photograph 1 shows the forming state.

The formed briquettes are dried in the continuous drier to become

the product. Since the semicoke as the raw material of briquettes

has strong ignition property and readily ignites in the furnace, the

drier is requested to operate at low temperature level. The drier

is designed considering the temperature-sensitive operation.

Coal Biomass

Pulverization

Drying

Mixing

Bio-briquette

High pressure briquetting

Caking additive may be required depending on the coal grade.

Deodorant

Caking additive

Pulverizing

Drying


59

3C4. Coal and Woody Biomass Co-firing Technology


1.Background�

As part of measures to arrest global warming, industrially

advanced countries are practicing mechanisms to promote the

adoption of power generation using renewable energy. One of

them is the RPS (Renewable Portfolio Standard) System. Since

April 2003, the "Special Measures Law concerning the Use of

New Energy by Electric Utilities (RPS Law)" has bee enacted,

obligating electric utilities to use a certain amount of new energy

for power generation. The normal usage (obligation amount) of

new energy for electricity is assumed to increase from 3.3GkWh

in 2003 to 12.2GkWh in 2010. What is defined as new energy

includes biomass fuel.

Co-firing of coal and woody biomass in the power generation

sector, though already under way in U.S. and European

countries, is a novel trial facing a variety of technological

problems. For pulverized coal-fired boilers, there are roughly two

methods of co-firing. One is to simply input woody biomass into

an existing mill (pulverizer) and grind it for the combustion of

pulverized coal-biomass mixture fuel in a boiler, using the

existing burner. This method requires less adaptation of

equipment and, therefore, less cost while there is a problem that

a mixture of more than several % biomass causes the mill’s

power consumption to sharply increase due to the difficulty in

grinding woody biomass with ordinary pulverizers. The other

method is to establish a biomass-dedicated mill. Despite the

equipment cost higher than the former, this method is

advantageous not only because the ratio of mixture may be

made higher but also because the amount of NOx generated can

be reduced.

Here, the latter method for which technology development is

under way, commissioned by the New Energy and Industrial

Technology Development Organization (NEDO), is introduced.

Fig.1 Coal/Woody Biomass Co-Firing System and Practiced Items

Combustion test/evaluation

Woody biomass technology investigation

Pre-treatment technology development

FS for commercialization

Coal

Woody biomass StorageSeparation Drying Grinding

Mill

Boiler

Burner

Exhaust gas treatment

In charge of research and development: New Energy and Industrial Technology Development Organization; the Chugoku Electric Power Co., Inc.; Hitachi, Ltd.; Babcook-Hitachi K.K.Project type: High-efficiency biomass energy conversion technology developmentPeriod: 2001-2003 (3 years)


1) Kazuhiro Mae: Coal Utilization Technology Information Journal No. 253 pp. 3~5 (Feb., 2002)

2) Hiroshi Yuasa: A collection of lectures from Oct. 2003 Thermal/Nuclear Power Generation Convention in Fukuoka, pp102/103

References


60

R&D Schedules

(1)Co-firing ratio of woody biomass: 5-10%

(2)Clearance of current regulatory environmental limits

(3)Existing coal thermal power plants-comparable power

generation efficiency: A decrease in net thermal efficiency to be

made 0.5% or less with the woody biomass co-firing ratio of 5%

(on a calorific base).

(1)Woody biomass pre-treatment technology mainly of grinding

(2)Woody biomass combustion technology (co-firing

burner/biomass-dedicated burner)

4.Development in progress and results

This project, under way jointly at the Chugoku Electric Power

Co., Inc., Hitachi, Ltd., and Babcook Hitachi K.K., commissioned

by NEDO, is now at the stage of FS for the evaluation of pilot

plant test combustion results toward commercialization.

Fig.2 Pilot Scale Test Equipments

2004 20052001 2002 2003

Coal/woody biomass co-firing technology R&D (a business commissioned by NEDO) Demonstration test

Development of component technologies for processes from reception to storage, crushing, dry boiler combustion, and then flue gas/ash disposal

Component technology development results-based deployment toward demonstration tests

1.Woody biomass technology investigation

2.Pre-treatment technology development

3.Combustion test and evaluation

4.FS for commercialization

Planning

Installation works

Supply system and other improvement/developmentUtilization planning and system design/verification

Demonstration test

[Review of forest biomass utilization by local governments]

2.Development target�

�

3.Technologies to be developed

Biomass

Feeder

Hopper

Crusher

Heater

To stacks

Cyclone

Drier

Mill [1]

Hopper

Feeder

Mill [2]

Bag filter

Bin

Blower

Burner

Furnace

Multi-Purpose Coal Utilization Technologies (De-ashing and Reforming Technologies)

61

3D1. Hyper-Coal based High Efficiency Combustion Technology(Hyper Coal)

Outline of the technology

1.Background and object�

Coal is expected to increase the demand owing to the abundant

reserves, the expectation of stable supply, and the low price,

though the influence of CO2 and other substances on the

environment is relatively large compared with other fossil fuels.

In the situation, to decrease the emissions of CO2 from coal fired

power plants which account for large percentage in the coal

utilization field, it is important to develop a power generation

technology of higher thermal efficiency than ever, and to bring the

technology widespread use over the world.

If coal is utilized as a gas turbine fuel, the adoption of combined

cycle power generation system (combination of gas turbine and

steam turbine) realizes higher efficient power generation than

that of existing pulverized coal fired power generation. To this

point, if coal can remove impurities such as ash and alkali

metals, the resulting clean coal can be used as fuel to directly

combust in gas turbine.

Regarding the issue, NEDO conducts development of technology

of combined power generation system, where the coal is treated

by solvent extraction and ion exchange to remove ash and alkali

metals to obtain clean coal (Hyper-Coal), which is then directly

combusted in gas turbines.

2.What is Hyper-Coal?�

A solvent having strong affinity with coal is applied to the coal

extraction, and then unnecessary ash is sedimented to remove

from the coal to obtain very low ash coal (Hyper-Coal).

3.Hyper-Coal production facilities�

(1)Preheating-extraction unit

Coal is extracted by a solvent, and then is

treated by rapid filtration to remove residue, thus

Hyper-Coal is produced. (Design temperature:

500OC, design pressure: 3MPa)

The unit produces various grades of Hyper-Coal

samples.

(2)Sedimentation-separation unit

The unit is a sedimentation tank having coal

extraction performance, (design temperature:

500OC, design pressure: 5 MPa). Vertically

arranged five valves collect samples to

determine the sedimenting condition of non-

dissolved ingredients under pressurized and

heated conditions.

Charcoal

Solvent CoalSolvent penetrates into coal

Cohesion of coal becomes weak, and soluble portions of coal dissolve.

Insoluble portions and ash are sedimented to remove. Extract residue

charcoal

Hyper-Coal

In charge of research and development: Center for Coal Utilization, Japan; National Institute of Advanced Industrial Science and Technology; and Kobe Steel, Ltd.Project type: Development and Survey of Next Generation Technology for Coal Utilization, promoted by New Energy and Industrial Technology Development Organization (NEDO)Period: 2002-2007 (6 years)

Fig. 1 Conceptual drawing of Hyper coal manufacturing from coal

Photo 1 Preheating-extraction unit Photo 2 Sedimentation separation unit



62

Coal is charged into the solvent, and the system is pressurized and heated to let the coal portions disperse into the solvent. Insoluble ash is treated by the settler to sediment by gravity to remove as the residue coal. The solvent containing dispersed coal portions is sent to the ion exchange vessels.

Ion exchange vessels remove alkali metals which cause high temperature corrosion.

The material is flash-sprayed into the drying tower to separate the solvent. The solvent is recovered to reuse.

The gas turbine combined cycle power generation system is a power generation system which combines gas turbine with steam turbine. When a gas turbine of 1350oC level of combustion gas temperature is used, about 20% of CO2 emission reduction is attained compared with the pulverized coal fired power generation system.

Conventional power generation system. Power is generated by combusting the residue coal.

Roughly deashed coal (ash content: 5% or less)

Overseas mining site (coal mine)

5.Configuration of Hyper-Coal based high efficiency power generation system

6.Concept of Hyper-Coal based power generation system 7.Schedule of research and development

Post-evaluation

Interim evaluation

Photo 3 Test apparatus for manufacturing Hyper coal continuously

4.Features of Hyper-Coal�

- Ash content is decreased to 200 ppm or lower level. Alkali

metals (Na, K) are decreased to 0.5 ppm or lower level by ion

exchange.

- Calorific value increases by about 10-20% from that of original

coal.

- Inorganic sulfur is completely removed.

- Content of solid state trace amount of heavy metals is

significantly decreased, (to 1/100 or smaller).

- The residue generated by 30-40% to the original coal during

the production stage can be used as general coal.

- The production cost is low, about 950-1,200 yen/ton-HPC.

- The HPC has excellent ignitability and burn-off property.

- The HPC shows high flowability, and is a good carbon material

for direct reduction iron and for smelting nonferrous metals.

- Since HPC is rich in volatile matter and is free from ash, it is

excellent gasification raw material, and it is expected to increase

high efficiency of gasification.

Fig.2 Fundamentals of Low-Rank Coal Upgrading

Multi-Purpose Coal Utilization Technologies (Deashing and Reforming Technologies)

63

3D2. Low-Rank Coal Upgrading Technology (UBC Process)



Brown and sub-bituminous coal resources accounting for about

50% of coal reserves are called low-rank coal whose applications

are limited due to its low heating value and spontaneous

combustion property. Many of these low-rank coals, however,

are featured such as by low sulfur/ash contents, unlike

bituminous coal. So if they could be efficiently upgraded and

converted into high-grade high-heating value coal, it will then

contribute not only to the security of stable energy supply but

also greatly to environmental problems. The low-rank coal

upgrading technology (UBC Process) is under development as a

technology to make effective use of such low-rank coal.

This process, an adaptation of slurry dewatering technology of

the brown coal liquefaction process, consists of 3 stages; 1)

slurry preparation/dewatering, 2) solid-liquid separation/solvent

recovery, and 3) briquetting.

Fig.1 Low-Rank Coal Upgrading Process (UBC Process) Scheme

At the stage of slurry preparation/dewatering, after pulvelized

high moisture low-rank coal is mixed with recycled oil (normally

petroleum light oil), then laced with heavy oil (such as asphalt),

and heated in a shell & tube-type evaporator, moisture is

recovered as water vapor. This water vapor is sent to the shell

side of the evaporator after pressurized by a compressor to use

the waste-heat as a heating source, thereby having so far

substantially saving energy consumption at the stage of

dewatering. Low-rank coal also contains numerous pores and

the moisture within them is removed in the course of

evaporation. During that time, laced heavy oil is effectively

adsorbed onto pore surfaces, thus preventing spontaneous

combustion. Moreover, the heavy oil expresses its nature to

water repellency, functioning to prevent the re-adsorption of

moisture and accumulation of heat of wetting. The right figure

shows this phenomenon conceptually.

Asphalt Slurry dewatering

Slurry preparation

Decanter

Solid-liquid separation

Evaporator (140OC/350kPa)

Solvent recovery

Recycle solventWaste water Upgraded brown coal (UBC)

Raw coal

Upgraded brown coal briquette

Capillary water

Surface water

In charge of research and development: Japan Coal Energy Center; the Institute of Applied Energy; Kobe Steel, Ltd.; Nissho Iwai Corp.Project type:1. Low-rank coal upgrading technology-related investigation2. Joint research of technologies applicable to coal producing countriesPeriod: 1. 1995-1998(4 years) 2. 1999-2004(6 years)


Asphalt

Befor dewatering After dewatering

Selective adsorption of asphalt onto pore surfaces

Photo 1 Briquetted UBC

Photo 2 Low-Rank Coal Upgrading Demonstration Plant

1) Toru Sugita et al: UBC(Upgraded Brown Coal) Process Development, Kobe Steel Engineering Reports, 53, 42 (2003)

Reference


64

At the stage of solid-liquid separation/solvent recovery, after

recycled solvent is recovered from the dewatered slurry by the

decanter, the recycled solvent remaining in the pores of upgraded

coal is also recovered by the steam tubular drier.

Upgraded coal obtained from UBC Process is still in a powdery

state, requiring to be briquetted due to the necessity of

transportation except when consumers are located nearby. The

upgraded coal, normally binder-less briquettable, can be easily

briquetted, using a double roll briquetter. The right figure shows a

photo of briquetted upgraded-coal.

�

2.Development target�

1)Upgrading cost

If bituminous coal with a heating value of 6,500kcal/kg is

assumed 20 dollars/ton in FOB price, the FOB price of 4,500-

kcal/kg sub-bituminous coal is supposed some 13 dollars/ton in

calorific equivalent. If it is assumed that, from this, upgraded coal

of 6,500kcal/kg should be obtained, the guideline for treatment

cost will be set around 7 dollars/ton. Even with advantages of

low-rank coal such as its low ash contents and other features

borne in mind, it is necessary to target about 7 to 9 dollars/ton for

treatment costs.

2)Thermal efficiency for upgrading

Thermal efficiency in the upgrading process needs to be 90% or

more so that higher thermal efficiency than at direct low-rank coal

firing power plants may be achieved in terms of overall

comparison from UBC firing power generation.

3.Development in progress and results�

The heating value of upgraded coal, though it is varied depending

upon coal properties has been improved to around 6,500kcal/kg,

with its spontaneous combustion problem also successfully

suppressed. It has also been confirmed that briquetted

upgraded-coal is similar to normal bituminous coal in easiness of

handling and re-crushing.

Furthermore, upgraded coal, if burnt, quite easily burns itself out

to leave almost no un-burnt portion even under low-NOx

combustion conditions, assuring that it also has excellent

characteristics as fuel.

4.Future assignments and prospective commercialization�

A demonstration-plant of 5 tons/day (raw coal-base) built in

Cirebon of the Java Barat province, Indonesia, is now in

operation, where the Ministry of Energy and Mineral Resources’

Research and Development Agency, Indonesia and the Japan

Coal Energy Center are main promoters.

In Asia-Oceania region, there are a lot of low-rank coal

resources. The coal mining companies, which have low-rank

coal, are highly interested in UBC process, hoping its earlier

commercialization.

65

4A1. Coal Ash Generation Process and Application Fields


Coal ash has, since it was commercialized as cement admixture

in the first half of the 1950’s, been widely used in applications

such as for cement raw material, cement mixture, roadbed

material, backfilling material, and piling-up material, finding its

way mostly in the cement sector, particularly, as cement raw

material (clay-alternative).

Coal burning methods are roughly divided as follows:

(1) Pulverized coal burning (dry-type)

(2) Stoker firing

(3) Fluidized-bed burning

(4) Circulating fluidized-bed burning

3.Physicality of coal ash�

In Japan, 90% or more of coal ash generated from pulverized

coal burning, dwarfing 7% or so from fluidized-bed and some 1-

2% from stoker burning. The generation ratio of fly ash and

clinker ash (bottom ash) is 90:10.

As for the shape of coal ash particle, low-melting point ash is

often globular while much of high-melting point ash is

indeterminate in shape. The average grain size of fly ash from

pulverized coal burning is about 25 m, similar to silt in fineness

between finer clay and coarser fine-grained sand for the use as

ground material.

The chemical composition abounds in silica (SiO2) and alumina (Al2O3),

resembling mountain soil, and these two inorganic components alone

account for 70-80% of total. Other than these, ferric oxide (Fe2O3),

magnesium oxide (MgO), and calcium oxide (CaO) are also contained in

slight amounts. In Japan, the physicality of coal wide varies since coal

of 100 brands or more is imported from all over the world.

2.Generation rate�

According to a questionnaire survey conducted by the Center for

Coal Utilization, Japan in 2001, the coal ash generation rate in

Japan is 8,810 thousand tons a year, up 5% in ratio or 380

thousand tons in quantity from the preceding year. Most coal-

firing boilers for the electric utility industry are those burning

pulverized coal. On the other hand, in general industries, 132

coal-firing boilers are in operation with an installed power

generation capacity of 1,000kW or more and, by burning

methods, the majority is accounted for by pulverized coal burning

(72 boilers). In terms of boiler capacity (steam generation rate),

boilers of 50t/h or less are mostly of a stoker burning type while

many of 100t/h or more burn pulverized coal.

Fig. 2 shows changes in the rate of coal ash utilization as well as

generation from electric power utilities and 1,000kW or more-

installed power generation capacity establishments in general

industries from 1993 through 2001.

Boiler

Steam turbine Generator

Transformer

Power transmission

Household/factory

Steam

Clinkerhopper

Economizer

Air pre-heater

Bottom ash(5~15%)

De-wateringtank

Dump truck Jet vac truck Dump truck Jet vac truck Dump truckTruckShip

Silo Silo Silo

Grader

Humidifier HumidifierBagger

Breaker

Electrostaticprecipitator

Fly ash

Coal-fired power plant

1.Background and general status of generation process�

�

Rate of Utilization

Rate of generation

Coa

l ash

(th

ousa

nd to

ns)

Year

Fig. 1. Process Example of Coal Ash Generation

from a Pulverized Coal-Firing Boiler

Source: Data from the Japan Fly Ash AssociationFig. 2. Changes in Coal Ash Generation and Utilization Rates

Chimney stack

(85~95%)

Part2 Outline of CCTEnvironmental Protection Technologies (Coal Ash Effective Use Technologies)

1) The Center for Coal Utilization, Japan: National Coal Ash Fact-Finding Survey Report (2001 results), (2003)

2) Environmental Technology Association/the Japan Fly Ash Association Coal Ash Handbook 2000 Edition, (2000)

3) Nobumichi Hosoda: CCUJ, Coal Ash Utilization Symposium lecture collection, (1998)

4) Natural Resources and Fuel Department, the Agency for Natural Resources and Energy: Coal Note (2003 edition), (2003)

References


66

4.Application fields�

Table 1 shows by-sector rates of effective utilization in 2001.

The utilization in the cement sector increases year after year,

reaching 5,343 thousand tons or 74.5% of the 7,173 thousand

tons used in all sectors combined. Recently, however, cement

production has been on a decrease and its future substantial

increase can hardly be expected. In coping with a likely increase

in coal ash in the future, therefore, an important task should be to

expand its utilization in other sectors, expecting its application as

civil engineering material in particular due to its high potential to

be used in large quantities.

Table 1 Breakdown of Fields for Effective Coal Ash Utilization (2001)

TotalItem

Total of effective utilization

Cement

Civil engineering

Construction

Agriculture/forestry/fisheries

Others

Cement raw material

Cement mixture

Cement admixture

Sub-total

Foundation improving material

Civil work-purpose

Power supply construction-purpose

Roadbed material

Asphalt/filler material

Coal mine filling material

Sub-total

Boards as construction material

Artificial light-weight aggregate

Secondary concrete product

Sub-total

Fertilizer (including snow melting agent)

Soil conditioner

Sub-total

Sewage treatment agent

Steel making-purpose

Others

Sub-total

3,608

140

87

3,835

271

67

20

47

3

320

728

191

24

35

250

42

10

52

3

1

402

406

5,271

68.45

2.66

1.65

72.76

5.14

1.27

0.38

0.89

0.06

6.07

13.81

3.62

0.46

0.66

4.74

0.80

0.19

0.99

0.06

0.02

7.63

7.70

100.00

Electric utilities General industry

DescriptionSector Rate of utilization

Composition ratio(%)

1,307

154

47

1,508

94

22

0

54

0

0

170

118

0

3

121

12

80

92

1

1

9

11

1,902

68.72

8.10

2.47

79.28

4.94

1.16

0.00

2.84

0.00

0.00

8.94

6.20

0.00

0.16

6.36

0.63

4.21

4.84

0.05

0.05

0.47

0.58

100.00

Rate of utilization


4,915

294

134

5,343

365

89

20

101

3

320

898

309

24

38

371

54

90

144

4

2

411

417

7,173

68.52

4.10

1.87

74.49

5.09

1.24

0.28

1.41

0.04

4.46

12.52

4.31

0.33

0.53

5.17

0.75

1.25

2.01

0.06

0.03

5.73

5.81

100.00

Rate of utilization


[unit : thousand tons]

Environmental Protection Technologies (Coal Ash Effective Use Technologies)

67

4A2. Effective use for Cement/Concrete



Utilization of fly ash in the cement sector has long been

challenged through investigations into pozzolana. Enhanced

research on the use of fly ash as a good-quality alternative to

pozzolana brought its first late-1940’s application to concrete

admixture of structures like a dam in the United States for

subsequent further dissemination into other countries. In Japan,

following its commercialization as cement admixture early in the

1950’s, standards were established for fly ash in 1958 and then

for fly ash cement in 1960, encouraging wide applications for

general concrete structures.

In the meantime, fly ash came to be used as a clay-alternative in

cement raw material in 1978 and, as of 2001, 68.5% of the total

rate of effective utilization is accounted for by such applications.

2.Utilization in the cement sector�

1) Utilization as a clay-alternative in cement raw material

Cement raw material is composed of lime stone, clay, silica, and

silver oxide, with clay accounting for 15% of total composition.

Coal ash containing silica (SiO2) and alumina (Al2O3) is also used

as an alternative to such clay. But it contains less SiO2 and more

Al2O3 than clay to require more silica as a source of SiO2 which

becomes short if coal ash is used in large quantities, thereby

limiting the substitutability of coal ash for clay. At present, about

5% of cement raw material is substituted by coal ash but its

alternative use is said theoretically possible to around 10%.

2) Utilization as cement mixture

JIS specifies standards for fly ash cement2), allowing fly ash to

be mixed by 5-30%. In general, fly ash can also be used as

Portland cement mixture by 5% or less.

3.Utilization in the concrete sector�

1) Utilization as concrete admixture

1. Dam concrete

In Japan, research on fly ash as concrete admixture started

around 1950, demonstrating its favorable performance and

economy through the first commercialization on a dam site in

1953.

RCD (roller compacted dam-concrete) is a concrete product

finished by compacting concrete of ultra-thick consistency with a

vibration roller and the then Ministry of Construction-led

independent technology development tried to rationally embody

this in a concrete dam, successfully systematizing the trial into

the RCD Construction Method to be commercialized for dam

construction in 1978.

Dam concrete is generally required not to become so hot for

prevented cracks. Due to this severe requirement for RCD, only

part of cement is replaced by fly ash for the purpose of limiting an

increase in temperature. The replacement ratio used is mostly

20-30%. As many as some 30 dams have so far been built by

this construction method, justifying its evaluation as a well-

established engineering method in terms of technology.

2. Pre-packed concrete

Pre-packed concrete is a concrete product fabricated by casting coarse

aggregate of a designated grain size into the mold form or place of

application beforehand and injecting mortar into voids there at an

appropriate pressure. The mortar used here must be one of high fluidity,

little material separation, and moderate expansibility and, for this

purpose, fly ash is generally mixed by 25-50%.

Application fields include underwater concrete, mass concrete, and

repair/reinforcement of existing concrete works. Honshu-Shikoku Bridge

substructure works also employed this construction method.

3. High-fluidity concrete

FEC (fly ash enriched concrete) is a two components-type high-

fluidity concrete product using cement and fly ash as powder

material. It contains as much as 40% or more of fly ash, giving

such features as the excellent self-filling capability to need no

compaction after cast, scarce cracks due to heat of hydration,

increasing long-term strength, and higher durability against alkali

aggregate reaction and salt/acid damages.

FS (fly ash and slag concrete) using steel slag and coal ash as

aggregate is a plain concrete product developed for wave-


1) The Japan Cement Association: Common Practice of Cement, (2000)

2) JIS R 5213-1997, (1997)

3) JIS A 6201-1999, (1999)

References


68

breaker superstructure works and foot protection/anti-turbulence

blocks which are not required to be so strong.

4. Industrial standards for concrete-purpose fly ash

Following the evaluation of fly ash as concrete admixture of

excellent performance due to its high fineness and few unburnt

carbon contents, high-fineness items were commercialized by

means of an advanced grader and higher-performance qualities

or qualities likely to prove effective as admixture despite their

sub-standard state were added to JIS Standards3) as 4th-grade

items, thereby facilitating the selection of a quality suitable for the

purpose of utilization. Class-1 fine fly ash is used as admixture

such as for concrete products that must cut off water, be durable,

etc. including ocean concrete and long haul- and pressure-

transported special back-filling material.

Item

Silica dioxide (%)

Moisture content (%)

Ignition loss *1(%)

Density (g/cm3)

Flow value ratio (%)

Fineness*2

Activity index (%) Material age: 28 days

Material age: 91 days

Class I fly ash

Class II fly ash

Class III fly ash

Class IV fly ash

45.0 or more

1.0 or less

1.95 or more

3.0 or less

10 or less

5000 or more

105 or more

90 or more

100 or more

5.0 or less

40 or less

2500 or more

95 or more

80 or more

90 or more

8.0 or less

40 or less

2500 or more

85 or more

80 or more

90 or more

5.0 or less

70 or less

1500 or more

75 or more

60 or more

70 or more

Residue on 45 m sieve (screen sieve method) *3(%)

Specific surface area (Blaine method) (cm2/g)

*1 In place of ignition loss, the unburnt carbon content ratio may be measured by the method specified in JIS M 8819 or JIS R 1603 to apply to the result a stipulated value of ignition loss.*2 Base fineness on a screen sieve method or Blaine method.*3 In case of a screen sieve method-based fineness, put down with the result of specific surface area tests by a Blaine method.

Class

Table 1 Quality of Fly Ash (JIS-A 6201)

Application to dam Application to building

69

4A3.Effective use for Civil Engineering/Construction and Others



Coal ash is widely used, other than for concrete, in the civil

engineering sector as road construction, foundation improving,

back-filling, or other earthwork material and in the construction

sector as artificial light-weight aggregate. On the other hand, in

the agriculture/forestry/fisheries sector, it is used as a fertilizer or

soil conditioner.

In coping with well-expected generation of coal ash in large

quantities in the future such as due to further establishment of

new coal firing power plants, utilization technologies are now

under active development out of the necessity to expand its

utilization in these sectors. Efforts to provide substance to this

face some problems including diffusion of technology, exploitation

of demand, and improvement of the distribution mechanism.

2.Utilization in the civil engineering�

1. Road construction material

The "Outline of Asphalt Pavement" 1) allows fly ash to be used as

asphalt filler material and clinker ash, as lower subbase material,

frost heave depressant, and cutoff layer material.

Fly ash can be used for the upper/lower subbase and road bed.

A cement stabilization treatment construction method adds fly

ash to cement to be treated under moderate moisture contents

for application. This construction method realizes early

manifestation of strength and achieves long-run stability. Another

technology2,3,4,5) has also been developed to process coal ash for

the use as road construction material.

2. Earthwork material

Fly ash can be effectively used as piling-up or back-filling

material since it is lighter than common earthwork material. In

recent years, therefore, various technology development

efforts6,7,8) have been made, coming up with a number of

applications including a usage in the original powder state with

cement added as a solidifier to coal ash, utilization as stabilizing

treatment material, hardening for application, and granulation or

other processing to use it. Review is also under way for intended

commercialization of fly ash as soft ground improving material or

a construction sludge conditioner due to its high activity of

pozzolana as well as property of self-hardening9).

Meanwhile, basic research of coal ash’s trace components

elution10) goes on since fly ash must be used, not raising any

environmental problems, in terms of safety coal-ash utilization as

earthwork material.

Photo 1 Application to road


1) The Japan Road Association: Outline of Asphalt Pavement, (1992)

2) Environmental Technology Association/the Japan Fly Ash Association: Coal Ash Handbook 2000 Edition, (2000)

3) Public Works Research Institute: Public Works-Related Material Technology/Technical Review Certification Report "Ash-Roban", (1997)

4) Public Works Research Institute: Public Works-Related Material Technology/Technical Review Certification Report "Pozzotech", (1997)

5) Ohwada et al: 11th Annual Conference on Clean Coal Technology lecture collection, (2001)

6) Shintani et al: CCUJ, Civil Engineering 54th Annual Academic Lecture Meeting, collection of summaries, (1999)

7) Public Works Research Center: Public Works-Related Material Technology/Technical Review Certification Report "Hard Soil-Break Material", (2000)

8) Akira Onaka: The Clean Japan Center’s 11th Resources Recycle Technology Research Presentation Meeting, collection of lecture papers, (2003)

9) Ozasa et al: CCUJ, 11th Annual Conference on Clean Coal Technology lecture collection, (2001)

10) The Japanese Geotechnical Society: Research Committee Report on Utilization of Wastes as Foundations Material, (2000)

11) Ishii et al: The "Bulletin of the Chemical Society of Japan", 5, 431, (1992)

12) Ozasa et al: CCUJ, 10th Annual Conference on Clean Coal Technology lecture collection, (2000)

13) Tatsuo Suzuki: 14th ACAA International Symposium lecture collection, (2001)

References


70

Photo 2 Example of Artificial Aggregate Fabricated from Coal Ash (Toughlite)

3.Utilization in the construction sector�

1. Artificial light-weight aggregate

Development efforts11,12) have successfully come up with

technology to palletize/calcine coal ash and cement or the like into

artificial light-weight aggregate. Demand for it is expected to grow

such as due to the progress of urban development and high rising

of buildings, making it important to further technology development

of artificial light-weight aggregate as well as to reduce its

production cost.

2. Others

The resemblance of its components to the chemical composition of

existing construction materials also allows coal ash to be used as

clay-alternative raw material for ceramic products such as clay

roofings, bricks, and tiles or a cement mixture for boards

(interior/exterior wall material for construction) on the strength of

such characteristics.

4.Utilization in the agriculture/forestry/fisheries sector

1. FertilizerCoal ash was designated in the capacity of pulverized

coal-burning ash as a special fertilizer in 1960 for fly ash and in

1992 for bottom ash. A potassium silicate fertilizer making

effective use of hard-to-solve silicic acid contained in coal ash is

also produced about thousands of tons a year.

2. Soil conditioner

Clinker ash whose chief ingredients are almost the same as

those of ordinary soil, mostly composed of SiO2 and Al2O3, is

suitable for the growth of vegetables. Moreover, it is used as sod

for golf courses or to improve soil of poor-drainage places or

arable land since its numberless spores hold water well for

longer duration of fertilizer effects and, at the same time, its

similarity to sand in shape provides comparable water-

permeability.

3.Utilization in the fisheries sector

There are long-established cases where coal ash was used for

fish breeding reefs and seaweed beds. A recent attempt aims at

the use of coal ash as mound material for man-made undersea

mountain ranges to cause artificial upwelling currents.13)

Photo 3 Application as fertilizer

71



Coal ash utilization technology is now an R&D subject challenged in

diversified manners from an effective-use-of-resources point of view.

Review has been made on the recovery of valuable resources

from coal ash by way of physical/chemical treatment, utilization

as an absorbent, catalyst, ion-exchanger, and desiccant through

zeolitization, desulfurization agent, antirust, and application such

as into admixture and filler of polymeric materials (including

rubber and plastic).

2.Valuable resources recovery�

Coal ash contains valuable substances including cenosphere

(hollow ash), Magnetite silica, alumina, iron oxide, and titanium

oxide, other than which valuable metals are also present though

in trace amounts.

1) Recovery of valuable resources through physical treatment

(1)Magnetite recovery through magnetic separation

The recovery of magnetite (Fe3O4) from fly ash is also positioned

at the pre-process of the chemical treatment method to recover

valuable elements such as Si, Al, Ti, and Fe. Magnetite can be

used, e.g., an alternative to heavy separation medium recovered

by magnetic separation.

2) Recovery of valuable resources through chemical treatment

(1)Direct hydrofluoric acid extraction method

As a method of recovering valuable resources from fly ash

through chemical treatment, the acid extraction method which

uses an acid mixture of hydrofluoric acid and hydrochloric acid

has been developed. The SiO2 recovered here is

characteristically of high purity (99.9% or more) and fine particles

(1 m or less).

(2)Calcination method

This method burns fly ash with a source of calcium to change

acid-stable mullite in fly ash into acid-soluble anorthite or

gehlenite, characteristically at a high rate of Al recovery.

Coal ash

Caustic soda

Water treatment stationWater drainage pitNaOH drainage pit

Fig. 1. Coal Ash Zeolite Production Process

3.Artificial zeolite�

Zeolite is the generic term of hydrated crystalline alumina silicate

and, as part of its features, has a porous structure and, therefore,

a large specific surface area as well as contains ion-

exchangeable cations and crystallization water that can be

adsorbed/desorbed. On the strength of its such characteristics,

Zeolite is used, e.g., as an adsorbent, catalyst, and disiccant1).

It is known that hydrothermal treatment of a coal ash-alkaline

aqueous solution mixture2) gives various kinds of zeolite,

depending upon conditions for reaction.

The Clean Japan Center3) now conducts demonstration tests at a

coal ash zeolite production demo-plant of a level of 10 thousand-

ton/year in 1990. At this coal ash zeolite production process,

coal ash zeolite is obtained if coal ash is boiled with sodium

hydroxide while stirring and then solid contents are

separated/washed/de-watered. The zeolite given here is of a Na-

P type.

Meanwhile, coal ash zeolite production processes so far

commercialized are batch-wise like those for other than coal ash

while flow-through continuous synthesis processes have also

been developed4). In addition, review is now made on the

exploitation of applications where large-quantity utilization is well-

expected, reduction of production costs, and technology to

synthesize zeolite of a kind suitable for each application.

Boiling/stirring Buffer tank Drainage Water

washing De-wateringPrimary products storage

Drying Bagging

4A4. Valuable Resources Recovery Technologies for Coal Ash


1) Environmental Technology Association/the Japan Fly Ash Association: Coal Ash Handbook 2000 Edition, (2000)

2) Akio Itsumi: Japan Soil Science and Plant Nutrition, 58 (3), (1987)

3) The Clean Japan Center: Clean Japan, 86, (1991)

4) Masahiko Matsukata: CCUJ, 12th Annual Conference on Clean Coal Technology lecture collection, (2002)

References


72

4.Utilization in other sectors�

1) Desulfurization agent

Dry desulfurization technology using coal ash has been

commercialized because a hardened mixture of coal ash, slack

lime, and gypsum has an excellent desulfurization capability.

2) Admixture/filler for polymeric materials (including rubber and

plastic)

Fly ash, since it is a gathering of small round glass bead-like fine

particles, is under review for its use as a rubber filler or as an

alternative to plastic admixtures including calcium carbonate,

silica, alumina, wood flour, and pulp.

3) Other

Other than the above, the present technology development also

envisages coal ash characteristics-based applications such as in

an agent to prevent rust due to oxidation in steel-making, a water

cleanup agent, or casting sand.

A

P

X

Cation-containing aluminosilicate found in different kinds for different structures/compositions, with each kind having its own performance and application.

AlO4

SiO4

Na12[(AlO2)12(SiO2)12]

27H2O

Na6[(AlO2)6(SiO2)10]

15H2O

Na86[(AlO2)86(SiO2)106]

264H2O

Na type: 4

Ca type: 5

Na type: 2.6

Na type: 7.4

Na type: 0.3

Na type: 0.36

Na type: 0.24

548

514*The figure is small but the exchange rate is small.

473

Structure Molecular formulaPore size

(A)Pore volume

(cc/g) CEC

(meq/100g)

Environmental Protection Technologies (Flue Gas Treatment and Gas Cleaning Technologies)

73

4B1. SOx Reduction Technology


1.Background�

Sulfur oxides (SOx, mainly SO2) is regulated by way of the K-

value control which uses exhaust heights and regional

coefficients to limit their emissions as well as the total amount

control which defines total emissions from the whole of a

region. In coping with these controls, flue gas desulfurizers

were commercialized in 1973, with later continual efforts for

their higher performance and lower costs. At present, most of

pulverized coal-fired thermal power plants are equipped with wet

lime stone and gypsum method-based desulfurization means.

Furthermore, a wet desulfurization method requiring no waste

water treatment is now under development.

2.Technology�

(1)Wet lime stone-gypsum method

Outline

The lime stone-gypsum method is found in a soot-separation

type which installs in its upstream a dedusting (cooling) tower

for dust collection, HCl/HF removal, and cooling or in a soot-

mixed type having no such tower. Soot-separation types are

used when high-purity gypsum containing no soot/dust is

desired. At present, however, more and more soot-mixed types,

less-expensive-to-install, are adopted since a high-performance

dust collection system like the advanced low-temperature

electrostatic precipitator has been developed, lowering

soot/dust concentrations.

In the absorption tower, on the other hand, water-mixed lime

stone slurry is reacted on SO2 within exhaust gas for the

recovery of sulfur contents as gypsum (CaSO4-2H2O).

The overall reaction is as follows:

CaCO3+SO2+0.5H2O CaSO3-0.5H2O+CO2

CaSO3-0.5H2O+0.5O2+1.5H2O CaSO4-2H2O

There are two types of absorption tower as shown in Fig. 1;

CaSO3-0.5H2O oxidation tower-separated types and all-in-one

internal oxidation types. At present, the utilization of less-

expensive-to-install/operate internal oxidation types is on a year-

after-year increase. Methods for causing recycled absorption

liquid to contact SO2 in the absorption tower section include

Spray Method to spray absorption liquid, Grid Method to shed

absorption liquid on the surface of a grid-like pad, Jet-Bubbling

Method to blow exhaust gas into absorption liquid, and Water-

Column Method to shed a fountain flow of absorption liquid in the

absorption tower.

For developing countries, a simple type installable in the flue gas

duct or at the lower part of a smoke stack has also been

commercialized.

Fig. 1 Outline of Lime Stone-Gypsum Method-Based Desulfurizer

Item Oxidation tower-separated type In-absorption tower oxidation type

Basic flow

Absorption tower

Sulfuric acid Oxidation

tower

Gypsum

Gas Gas

Lime stone Lime

stone

Absorption tank Absorption tower tank

Gypsum

Air

Air

Absorption tower

Members in charge of research and development: Mitsubishi Heavy Industries, Ltd.; Babcook Hitachi K.K.; Ishikawajima-Harima Heavy Industries Co., Ltd.; CHIYODA Corporation; Kawasaki Heavy Industries, Ltd.; others


1) "Introductory Course: Environmental Preservation Technology /Equipment for Thermal Power Plants IV Desulfurization Equipment",

Thermal/Electronic Power Generation Vol. 41 No. 7,911, 1990

2) Kudo et al, "Coal Ash-Based Dry Desulfurizer Development" Thermal/Electronic Power Generation Vol. 41 No. 7,911, 1990

3) "Coal Ash-Based Dry Flue Gas Desulfurizer" pamphlet, Hokkaido Electric Power

4) General View of Thermal Power Generation, Institute of Electric Engineers, 2002

References


74

(4)Furnace desulfurization method

Outline

It is a desulfurization method used for fluidized-bed boilers.

Lime stone for desulfurization is mixed with coal to be fed

together with coal, causing the following reaction to remove

SO2 at a furnace temperature of 760-860OC:

CaCO3 CaO+CO2 CaO+SO2 CaSO3

At present, this method is in practice at normal-pressure

fluidized-bed boilers of J-POWER’s Takehara Thermal Power

Plant No. 2 Unit as well as pressurized fluidized-bed boilers of

Hokkaido Electric Power’s Tomato-Atsuma Thermal Power

Plant, Kyushu Electric Power’s New Kanda Thermal Power

Plant, and Chugoku Electric Power’s Osaki Thermal Power

Plant. At pressurized fluidized-bed boilers, lime stone does not

break down into CaO due to the high partial pressure of CO2

but SO2 is removed in accordance with the following reaction:

CaCO3+SO2 CaSO3+CO2

(3)Spray Drier Method

Outline

It is a so-called semi-dry method, where water is added to burnt

lime (CaO) to make slack lime (Ca(OH)2) slurry, which is sprayed

into a spray drier, causing SO2 in exhaust gas to react on

Ca(OH)2 to be removed. Within the drier, desulfurization

reaction and lime stone drying take place at the same time,

giving a particle mixture of gypsum (CaSO4-H2O) and calcium

sulfite (CaSO3-0.5H2O). These particles are recovered at a

down-stream precipitator. Since this method is not enough for

good-quality gypsum to be obtained and, moreover, ash remains

mixed in, desulfurized particles are disposed of as waste.

Electric Power Development Company, as part of the "Green Aid

Plan," installed a spray drier desulfurizer with an exhaust gas

treatment capacity of 300Km3N/h (half of total exhaust), which is

currently in operation, at Huangdao Power Plant No. 4 Unit

(210KkW) in Qingdao, China, for 70% desulfurization rate

verification tests (Oct., 1994 through Oct., 1997).

Fig. 2 Coal Ash-Based Dry Desulfurization Method Proces

(2)Coal ash-based dry desulfurization method

Outline

It is one of technologies developed to make effective use of

coal ash. This method is to fabricate a new absorption spent

from lime stone, calcium hydroxide (Ca(OH)2), and spent

absorption agent and then, using the absorption agent, remove

SOx from flue gas. Fig.2 shows an outline of its process. This

process also includes the stage to manufacture the absorption

agent. Desulfurization reaction here is a reaction which allows

Ca(OH)2 to remove SO2. Temperature is conditioned at 100-

200OC, where an SOx removal efficiency of 90% or more can be

obtained. The process is also capable of dust collection and

De-NOx, having achieved a NOx removal efficiency of about

20% and dust collection efficiency of 96% or more. By 2003, it

had been installed at No. 1 unit (350 KkW) of Hokkaido Electric

Power’s Tomato-Atsuma Thermal Power Plant as a facility

currently in operation to treat half of its flue gas in amount.

Desu

lfuriz

ation

silo

Weig

hing

mac

hine

Pre-a

bsorp

tion a

gent

Prim

ary a

bsor

ption

age

nt

Used desulfurization agent

Water

Extruder

Conveyor

SteamWeighing machine

Steam generator

Screen

Hot air

Drier

BreakerUsed desulfurization agent

Desulfurization fan

Exhaust gasBoiler

Kneader

Coa

l ash

Slac

k lim

e

Conveyor

Blender

Members in charge of research and development: Hokkaido Electric Power Co., Inc.; Hitachi, Ltd.; Babcook Hitachi K.K.Kind of project: Subsidized development of oil-alternative energy-related technology for commercializationDevelopment period: 1986-1989

Members in charge of research and development: Electric Power Development Company; Mitsubishi Heavy Industries, Ltd.; Hokkaido Electric Power Co., Inc.Kind of project: Voluntary under the Green Aid Plan

Members in charge of research and development: Hokkaido Electric Power Co., Inc.; Kyushu Electric Power Co., Inc.; Electric Power Development Company; Chugoku Electric Power Co., Inc.; Mitsubishi Heavy Industries, Ltd.; Ishikawajima-Harima Heavy Industries Co., Ltd.; Kawasaki Heavy Industries, Ltd.Kind of project: Voluntary project

Clean gas

75

4B2. NOx Reduction Technology

Outline of tecnology

1.Background�

Nitrogen oxides are under regulatory control, setting acceptable

values of their concentrations by fuel kinds and boiler sizes.

Currently, however, with regulations further intensified, some

regions are subject, like sulfur oxides, to the total amount control

which provides for overall emissions from each region. In coping

with these regulations, flue gas denitration equipment was

commercialized in 1977, with later continual efforts to improve

the durability of De-NOx catalysts as well as reduce costs. The

De-NOx method used is Selective Catalytic Reduction (SCR)

Method to decompose nitrogen oxides mainly by using

ammonia.

2.Technology�

(1)Selective contact reduction method

Outline

In this method, ammonia (NH3) is blown into exhaust gas,

allowing ammonia (NH3) to selectively react on nitrogen oxides

NOx(NO, NO2), and decomposed them into water (H2O) and

Nitrogen (N2). In the De-NOx reactor, since exhaust gas entails

soot and dust, a grid- or plate-like catalyst is mainly used, as

shown in Fig. 1. The catalyst is filled in the reactor, as shown in

Photo 1/Photo 2, to react on the NH3 blown into the catalyst layer

from its inlet, allowing NOx(NO, NO2) to break down into water

vapor (H2O) and nitrogen (N2). The catalyst is mainly composed

of TiO2, to which vanadium (V), tungsten (W), and the like are

added as active ingredients.

4NO + 4NH3 +O2 4N2 + 6H2O

The temperature range is 350OC, at which the catalyst can

demonstrate its performance. At a lower temperature than this,

SO3 in exhaust gas reacts on NH3, giving ammonium hydrogen

sulfate (NH4HSO4) to cover the catalyst surface, thereby

reducing the De-NOx performance. At a temperature higher than

350OC, the NH4HSO4 decomposes, offering high De-NOx

performance, regardless of SO3 concentrations. At a high

temperature above 400OC, NH3 is oxidized to decrease in

amount, thereby reducing the De-NOx performance. The

process is also so designed that NH3 leaked from the reactor

should amount to 5ppm or less and if much NH3 leaks, it will

react on SO3 in exhaust gas, giving NH4HSO4, which is

separated out in the air pre-heater to clog the piping.

NOx removal efficiency is around 80-90% for pulverized coal-

fired thermal power plants. On the other hand, measures for

equal dispersion/mixture of NH3 in exhaust gas as well as

greater uniformity of exhaust gas flows to cope with growing

boiler sizes are contrived such as by placing a current plate

called Guide Vane at the gas inlet or dividing the gas inlet into

grids to be each equipped with an NH3 injection nozzle.

Fig. 1 Selective Contact Reduction Method Denitration Process

Photo 2 Plate-like catalystPhoto 1 Grid-like catalyst

Catalyst layer

Smokestack

Exhaust gas

Reactor

Members in charge of research and development: Mitsubishi Heavy Industries, Ltd.; Ishikawajima-Harima Heavy Industries Co., Ltd.; Babcook Hitachi K.K.

Part2 Outline of CCTEnvironmental Protection Technologies (Flue Gas Treatment and Gas Cleaning Technologies)

1) Masahiro Ozawa et al, "Latest Flue Gas Denitrator Technology", Ishikawajima-Harima Technical Journal, Vol. 39 , No. 6, 1999

2) Tadamasa Sengoku et al, "Selective Non-Catalytic Denitration Method for Boilers", Thermal/Nuclear Power Generation,

Vol. 29, No. 5, 1978

3) Coal Utilization Next-Generation Technology Development Survey;

Environment-friendly coal combustion technology field (advanced flue gas treatment technology)/NEDO results report, March 2002

4) Masayuki Hirano, "New Flue Gas Denitrator Technologies for Large Boilers/Gas Turbines", Thermal/Electronic Power Generation,

Vol. 50, No. 8, 1999

References


76

(3)Radical injection method

Outline

This method, as shown in Fig.3, injects argon plasma into NH3,

generating NH2-, NH2-, and other plasmas, which are then blown

into the boiler to decompose NOx into H2 and H2O. It is a

technology aimed at NOx concentration of 10ppm or less for its

target performance.

At present, basic research is under way at the Center for Coal

Utilization, Japan, toward expected commercialization around

2010.

(2)Selective Non-Catalytic Reduction (SNCR) Method

Outline

It is a method to, as shown in Fig.2, blow NH3 into the boiler

section where exhaust gas temperature is 850-950OC and break

down NOx into H2 and H2O without any catalyst. Despite its

merits of requiring no catalyst and lower installation costs, this

method achieving NOx removal efficiency of as low as some

40% at the NH3/NOx molar ratio of 1.5 is used in

regions/equipment where there is no need for high NOx removal

efficiency. More NH3 is also leaked than by the selective contact

reduction method, claiming measures to cope with NH4HSO4

precipitation in the case of high-SO3 concentration exhaust gas.

This technology is mainly used such as at small commercial

boilers and refuse incinerators. With respects to thermal power

plant applications, it was installed only at Chubu Electric Power’s

Chita Thermal Power Plant No. 2 Unit (375kw) in 1977. Fig. 2 Selective Non-Catalytic Denitration Method’s NOx Removal Process

Fig.3 Outline of Radical Injection Method

Members in charge of research and development: Chubu Electric Power Co., Inc.; Mitsubishi Heavy Industries, Ltd.Kind of project: Voluntary project

Members in charge of research and development: Center for Coal Utilization, JapanKind of project: Subsidized coal production/utilization technology promotionDevelopment period: 1999-2002

Air for dilution

Brin

e w

ater

for n

ozzl

e-co

olin

g

SAHFDF

AH

Injection nozzle

AmmoniaMixer

Booster fan

77

4B3. De-SOx and De-NOx Technology


1.Background�

A wet desulfurization method is also matured in terms of

technology but requires a variety of feed water as well as

advanced waste water treatment measures. Meanwhile, an

already commercialized ammonia selective reduction (SCR)

method needs not only life control of expensive De-NOx catalysts

but also measures against leaked ammonia. Development

efforts are, therefore, under way for a dry combined

desulfurization De-NOx method to remove NOx and SOx at the

same time without any feed/waste water treatment or De-NOx

catalyst.

Photo 1 Active Carbon-Method Desulfurizer

2.Technology�

(1)Active carbon adsorption method

Outline

The active carbon absorption method is to cause a reaction

between SO2 in exhaust gas and blown-in NH3 on active carbon

at 120-150OC, thereby converting SO2 into such form as

ammonium hydrogen sulfate (NH4HSO4) and ammonium sulfate

((NH4)2SO4) for adsorption/removal while decomposing NOx into

nitrogen and water as SCR Method does. Fig.1 shows the

process. The moving-bed adsorption tower (desulfurization

tower) at the first-stage removes SO2 and, at the second stage

(denitration tower), NOx is decomposed. This method first

removes SOx and then NOx since, as shown in the figure, the

presence of high-concentration SO2 tends to lower NOx removal

efficiency.

Active carbon that has absorbed NH4HSO4 is heated to 350OC or

above in the desorption tower to desorb NH4HSO4 after

decomposing it into NH3 and SO2 while active carbon is

regenerated. In the desulfurization tower, SO2 can be adsorbed

and removed in the form of sulfuric acid (H2SO4) even if NH3 is

not blown in but since, at the time of this desorption, the following

reaction with carbon contents occurs, consuming active carbon,

NH3 is added at the time of desulfurization for the purpose of

preventing this.

H2SO4 SO3+H2O

SO3+0.5C SO2+CO2

Desorbed SO2 is reduced into elemental sulfur by coal at 900OC

to be recovered. There is another method which oxidizes SO2

into SO3 to recover it as sulfuric acid.

During the development of this technology carried on at J-

Power’s Matsushima Thermal Power Plant, first, an active carbon

desulfurization method (with an adsorption tower unit) that can

treat gas of a 300Km3N/h (90KkW-equivalent) level in amount

was subjected to verification tests (1983-1986), obtaining 98%

SOx and some 30% NOx removal efficiency. For further

improvement in De-NOx performance, a combined

desulfurization De-NOx pilot plant that can treat 3,000m3N/h of

gas with two tower units was tested (1984-1986). SOx was

almost completely removed by the desulfurization tower at the

first stage, with De-NOx performance also achieving 80% NOx

removal efficiency. This technology, verified after upscaled to a

capacity to treat gas of a 150Km3N/h level in amount, was

adopted in 1995 for the De-NOx unit of Takehara Coal Thermal

Power Plant No. 2 Unit’s normal-pressure fluidized-bed boiler

(350KkW) and is currently in operation. It was further installed in

2002 at J-Power’s Isogo Thermal Power Plant No. 1 New Unit

(600KkW) as its desulfurizer (Photo 1) currently in operation but

none is operated as combined desulfurization-denitration

equipment.

Fig.1 Active Carbon-Method Desulfurization Process

Exhaust gas

Desulfurization tow

er

Denitration tow

er

Desorption tow

er

Active carbon

Hot air

Hot air

Desorbed gas

Members in charge of research and development: Electric Power Development Company; Sumitomo Heavy Industries, Ltd.; Mitsui Mining Co., Ltd.Kind of project: Voluntary support project for coal utilization promotion

Environmental Protection Technologies (Flue Gas Treatment and Gas Cleaning Technologies)


1) Hanada et al, "Dry Desulfurization-Denitration-Technology Dry Active Carbon-Method Sulfur Recovery Formula at Coal Thermal Power Plant"

Thermal/Electronic Power Generation, Vol. 40, No. 3, 1989

2) "Renewing Isogo Thermal Power Plant" pamphlet, Electric Power Development Company

3) Aoki, "Electronic Beam Flue Gas Treatment Technology", Fuel Association Journal, Vol. 69, No. 3, 1990

4) S. Hirono et al, "Ebara Electro-Beam Simultaneous SOx/NOx Removal", proc 25th Int Tech Conf Util Sys 2000

References


78

(2)Electron beam method

Outline

This method, as shown in Fig.2, injects an electron beam on

SOx/NOx in exhaust gas and blown-in NH3 to cause a reaction

for their recovery as ammonium sulfate ((NH4)2SO4) or

ammonium nitrate (NH4NO3) in the downstream precipitator. By-

products; ammonium sulfate and ammonium nitrate are used as

fertilizers. The performance of 98% or more SOx and 80% NOx

removal efficiencies for the NH3/NO molar ratio of 1 is obtained at

70-120OC. NOx removal efficiency also characteristically

increases with increasing SO2 concentration, though SOx

removal efficiency does not affect the inlet concentration of SO2.

For this method, technology development was undertaken by

Ebara Corporation and U.S. partners including DOE through their

joint contributions (1981-1987). In Japan, based on development

results, a pilot plant (that can treat gas of 12,000m3N/h) was built

at Chubu Electric Power’s Shin-Nagoya Power Plant, where the

technology has been verified (1991-1994).

Regarding this technology, a plant that can treat gas of

300Km3N/h (90KkW) (Photo 2) was installed at Chengdu Heat-

Electricity Factory (co-generation power plant) in Sichuan

province, China, and currently in operation for demonstration

under 80% NOx removal efficiency conditions.

Air

Electron beam generatorDry electrostatic precipitator

Smokestack

Ammonia equipmentCooling tower

Reactor

Nitrogen fertilizer (ammonium sulfate/ammonium nitrate)Granulator

Cooling water

Fig.2 Electron Beam-Method Desulfurization Process

Photo 2 Electron Beam Method Desulferizer

Existing �boiler

Air pre-heater

Dry electrostatic precipitator

Members in charge of research and development: Ebara Corporation; Chubu Electric Power Co., Inc.; the Japan Atomic Energy Research Institute; othersKind of project: Voluntary project

79

4B4. Soot/dust Treatment Technology and Trace Elements Removal Technology


1.Background�

Soot and dust are regulated, like NOx, under the provisions for

by-fuel kind/-boiler size concentrations. At present, however,

there are some regions subject to the total amount control which

limits the overall emissions from each region as in the case of

sulfur and nitrogen oxides. In coping with such regulations, an

electrostatic precipitator was employed in Yokosuka Thermal

Power Plant for the first time in the world in 1966 for mainly other

thermal power plants to follow suit. Development of pressurized-

bed combustion and coal gasification combined-cycle

technologies is also under way for high-efficiency power

generation, using cyclones and ceramics/metal precision-removal

filters.

On the other hand, trace materials-related control is now being

intensified such as through the addition of boron (B) and

selenium (Se) to waste water materials to be regulated and U.S.

regulations on mercury (Hg).

2.Technology�

(1)Electrostatic precipitation method

Outline

The electrostatic precipitation method is a method to remove

soot/dust in exhaust gas in accordance with the theory that any

dust negatively charged by corona discharge at the discharge

electrode adheres to the positive dust-collecting electrode. The

soot/dust that adhered to the electrode is allowed to come off and

drop by giving a shock to the electrode with a hammering device.

The dust collection performance depends upon the electrical

resistance of soot/dust, preferring particles of 104-1011 -cm in

the apparent electrical resistivity range. In the case of pulverized

coal thermal, electrical resistance of many particles is high,

urging various measures to be taken against high-electrical

resistance particles.

As one of such measures, temperature conditions for dust

collection are adjusted. Electrical resistance changes as shown

in Fig.2. Those successfully developed/commercialized from the

use of such characteristics are a high-temperature electrostatic

precipitator run at 350OC, a higher temperature than that of

conventional low-temperature electrostatic precipitators (130-

150OC) to lower electrical resistance and an advanced low-

temperature electrostatic precipitator run, with its electrical

resistance lowered by operating it at a dew point-or-lower

temperature (90-100OC). Other than these, successful

commercialization is found in the moving electrode method which

brushes off soot/dust by moving the electrode to prevent back

corona due to dust accumulation at the electrode and a semi-wet

electrostatic precipitator where a film of liquid is shed to wash

away dust. Another measure has also been taken with electric

discharge methods commercialized, including an intermittent

charge method to supply a pulsed voltage on the order of several

milliseconds and a pulse charge method for tens of

microseconds-order energization.

At present, leading pulverized coal-firing plants built in and after

1990 are provided with very low-temperature electrostatic dust-

collection means that can treat different properties as well as

shapes of soot/dust.

DC high voltage

Flue gas (from boiler)

Power supply

Discharge electrode

Collected soot/dust

Dust collecting electrode

Fig. 2 Temperature Effects on Electrical Resistance of Coal Ash

Fig. 1 Theory of Electrostatic Precipitator

Ele

ctric

al r

esis

tivity

(

-cm

)

Low-alkali/high-sulfur coal

Low-alkali/low-sulfur coal

Adv

ance

d Lo

w-te

mpe

ratu

re E

SP

Conv

entio

nal lo

w-te

mpe

ratu

re E

SP

High-alkali/high-sulfur coal

High-alkali/low-sulfur coal

Temperature(OC)

Hig

h-te

mpe

ratu

re E

SP

Members in charge of research and development: Mitsubishi Heavy Industries, Ltd.; Hitachi, Ltd.; Sumitomo Heavy Industries, Ltd.; others


1) "Thermal/Nuclear Power Generation Companion, 6th edition", Thermal/Nuclear Power Generation Association, 2002

2) Sato, "Design and Actual Operations of High-Temperature Electrostatic Precipitators", Thermal/Nuclear, Vol. 34, No. 4, 1983

3) Tsuchiya et al, "Technology Development of Low Low-Temperature EP in Coal Thermal-Purpose High-Performance Flue Gas Treatment System",

MHI Technical Journal Vol. 34, No. 3, 1997

4) "Toward the Realization of Integrated Gasification Combined-Cycle Power Generation", CRIEPI Review, No. 44, 2001

5) Coal-Based Next-Generation Technology Development Survey

/Environment-Friendly Coal Combustion Technology Field (Trace Element Measurement/Removal Technology), NEDO results report, 2003

References


80

(2)High-temperature dust collection method

Outline

This is under development as a technology to remove soot/dust

from hot gas for pressurized-bed combustion and integrated

gasification combined-cycle (IGCC) power generation processes.

This technology utilizes a multi-cyclone, ceramics- or metal-

based filter and the granular-bed method using silica or mullite

material where soot/dust is removed. Multi-cyclones are mainly

used for rough removal. Those used for precision removal

include ceramic or metal filters of a cylindrical porous body into

which SiC and other inorganic materials and iron-aluminum

alloys are formed (Photo 1). Such filters used here were

developed by Nihon Garasu Kogyo or overseas by Paul

Schumacher. Such technologies, now under durability

evaluation/demonstration, are used for pressurized-bed

combustion power generation at Hokkaido Electric Power’s

Tomato-Atsuma Thermal Power Plant, with their verification tests

conducted not only for IGCC at 200-ton/day Nakoso IGCC Pilot

Plant but also under the EAGLE Project. It is also expected to

be used at an IGCC demonstration unit (250KkW) slated for

initial operation in 2007.

(3)Mercury removal method

Outline

Among trace contents of coal, mercury is cited as a material

released into the atmosphere at the highest rate, with about 30

percent of the failure to be removed at precipitators/desulfurizers

proved to be released. However, bivalent mercury (Hg2+) is

nearly all removed, leaving nonvalent one (Hg) as discharge

matter. A method to remove this nonvalent mercury is under

active review. The Center for Coal Utilization, Japan, though still

in the process of basic research, selected active carbon, natural

inorganic minerals, and lime stone as materials which absorb

mercury and is now evaluating their absorption characteristics.

The research results prove that, if the method to inject active

carbon or an FCC ash catalyst into the flue for the removal of

metal mercury is combined with removal at the flue gas

desulfurizer, 90% or more mercury can be removed easily.

Photo 1 SiC Ceramic Filter

Members in charge of research and development: Mitsubishi Heavy Industries, Ltd.; Hitachi, Ltd.; Kawasaki Heavy Industries Co., Ltd.; others

Members in charge of research and development: Center for Coal Utilization, JapanKind of project: Subsidized coal production/utilization technology promotion project

1) Nakayama et al, "Development State of 3 Dry Gas Cleanup Methods in Dry Gas Cleanup Technology Development for Integrated

Gasification Combined-Cycle Power Generation", the Japan Institute of Energy Journal, Vol. 75, No. 5, 1996

2) Shirai et al, "Coal Gasification Gas-Based Fixed-Bed Dry Desulfurization Technology Development",

the Society of Powder Technology, Japan’s journal, Vol. 40, No. 8, 2003

3) M. Nunokawa et al, "Developments of Hot Coal Gas Desulfurization and Dehalide Technologies for IG-MCFC Power Generation System",

CEPSI proceedings 2002 Fukuoka

References


8281

4B5. Gas Cleaning Technology


1.Background�

For the development of coal gasification gas-based power

generation and fuel synthesis technologies, it is necessary to

remove sulfur compounds (H2S, COS), halides (HCl, HF), and

other gas contents. As shown in Fig.1 a main application of this

technology is found in the wet gas purification method which, after

removing water-soluble halides and other contents by a water

scrubber, desulfurizes the gas with a methyldiethylamine (MDEA)

or other amine-based liquid absorbent for gas purification. This

method, however, requires the gas to be cooled down to around

room temperature, thus losing much heat. Furthermore, the

process becomes complex since it requires not only a heat

exchanger but also a catalyst which changes hard-to-remove COS

into H2S. It is also difficult to precisely reduce sulfur compounds to

a 1-ppm level.

For solution of problems with such a wet gas purification method,

efforts are now exercised to develop dry gas purification

(2)Dry dehalogenation method

Outline

For the use of coal gasification gas in molten carbonate/solid

oxide fuel cells and fuel synthesis, it is necessary to remove not

only soot/dust and sulfur compounds but also halogen

compounds.

For the adaptation to these technologies, efforts are under way

to develop a halide absorption agent capable of reduction to

1ppm or less. At present, a method to remove HCl/HF contents

of gas as NaCl/NaF, using a sodic compound is under

development. CRIEPI test-made a sodium aluminate (NaAlO2)-

based absorbent, confirming possible reduction to 1ppm or less,

but such efforts still remain on a laboratory scale as well as

developing stage. This method faces an important problem of

how the absorbent should be reproduced or recycled.

Fig.5 Moving-Bed Combined Dust Collection-Desulfurization Process

Fig.4 Fixed-Bed Desulfurization Process

2.Technology�

(1)Dry desulfurization method

Outline

It is a method in which, as shown in Fig. 2, metal oxides are

reduced by coal gasification gas, and reduced metal oxides

remove sulfur compounds from gas, then are converted to

sulfides. This method can be used more than once by letting

sulfides react with oxygen for the release of sulfur contents as

SO2 to bring back metal oxides.

The development of this method as a technology for integrated

gasification combined-cycle power generation (IGCC) was

promoted, targeting to reduce sulfur oxides to 100ppm or less in

the temperature range of 400-500OC where economical carbon

steel can be used for piping. As the metal oxide to be used, iron

oxide was selected and Ishikawajima-Harima Heavy Industries

Co., Ltd. built a fluidized-bed desulfurization pilot plant (Fig.3)

that can treat the total amount of coal gas, using 100-200- m

iron ore particles, and is now under verification for performance,

under the 200-Ton/Day Nakoso IGCC Pilot Plant Project (1991-

1995). On the other hand, the Central Research Institute of

Electric Power Industry and Mitsubishi Heavy Industries, Ltd. ,

assuming its use in fixed-bed desulfurization systems (Fig.4),

have jointly developed an iron oxide-based honeycomb

desulfurization agent. They also built, under the 200-Ton/Day

Nakoso IGCC Pilot Plant Project (for coal gas production of

43,600m3N/h in amount), a pilot plant that can treat the amount

of coal gas produced by a tenth and is under verification of

performance. Meanwhile, Kawasaki Heavy Industries, Ltd. has

developed an iron oxide-based highly wear-resistant granular

desulfurization agent for use in a moving-bed combined-

desulfurization/dust collection system (Fig.5) and evaluated its

performance at the pilot plant capable of treating the 1/40 amount

of coal gas produced, which was buiilt under the 200-Ton/Day

Nakoso Pilot Plant Project. This fact indicates that IGCC-

dedicated technologies have already reached their validation

stage.

At present, a desulfurization agent that can reduce sulfur

compounds to a 1ppm level is under development for use in such

applications as molten carbonate fuel cells, solid oxide fuel cells,

and fuel synthesis. At the Central Research Institute of Electric

Power Industry (CRIEPI), a desulfurization agent using zinc

ferrite (ZnFe2O4), a double oxide of iron and zinc, has been

developed and found capable of reduction to 1ppm or less, now

being at the stage of real-gas validation. Efforts to cope with air-

blown entrained-bed gasification gas have so far been the main

theme of review while another important problem is adaptation to

high-carbon monoxide concentration gas like oxygen-blown

gasification gas which degrades the desulfurication agent by

allowing carbon to be separated out in it.

Coal gasifier

Ceramic filter

COS conversion catalyst

Scrubber (dehalogenation, deammonification)

Sulfur recovery equipment

Renewal towerH2S absorption tower Reboiler

Reduction

Mt: Elementary metal

Reproduction Desulfurization

Fig. 2 Desulfurization Reaction Cycle

Fig. 1 Wet Gas Purification Process

Cyclone

Desulfurization agent

Desulfurization tower

Coal gas

Dust filter

Reproduction tower

Carrier

To dust collector

Anthracite

SOx reduction tower

Sulfur condenser

Air

AshSulfur

Fig.3 Fluidized-Bed Desulfurization Process

Coal gas (from dust collector)

Desulfurization process Reduction process

To gas turbine

Gas for sulfur reduction

Air

Reduction process

Gas in excess

Heat exchanger

Sulfur recovery equipment

Sulfur

Separator

Distributor

Air

Reduction gas (coal gas)

Coal gas

Soot/dust filter

Soot/dust

To sulfur recovery system

To sulfur recovery system

To gas turbine

Desulfurization agent carrier

Members in charge of research and development: Center for Coal Utilization, Japan; IGCC Research Association; Technology Research Association for Molten Carbonate Fuel Cell Power Generation System; Central Research Institute of Electric Power Industry; Electric Power Development Company; Ishikawajima-Harima Heavy Industries Co., Ltd.; Mitsubishi Heavy Industries, Ltd.; Kawasaki Heavy Industries, Ltd.Kind of project: Voluntary project /NEDO-commissioned businessDevelopment period: 1986-1998

Members in charge of research and development: Central Research Institute of Electric Power IndustryKind of project: Voluntary project

1. Regeneration tower2. Reduction tower3. Desulfurization tower


Environmental Protection Technologies (CO2 Recovery Technologies) Clean Coal Technologies in Japan

83 84

4C1. Hydrogen Production by Reaction Integrated Novel Gasification Process (Hypr-RING)

Outline of Technology

1.Background�

Coal, the world’s most abundantly reserved energy resources, is

used as important primary energy due to its excellence in economic

terms as well. Its consumption is expected to increase with the

growth of economy as well as increasing population in the future.

Meanwhile, solution of global environment problems, to begin with

the global warming due to CO2, has become a task assigned to

human beings, earnestly claiming a technology to use coal clean

and more efficiently, particularly, a technology contributing to CO2

reduction. HyPr-RING Process is now under development for

commercialization as a technology which, in an attempt to answer

such a claim, enables hydrogen necessary for future hydrogen-

energy communities to be produced from coal and supplied.

3.Characteristics of HyPr-RING Process �

Cold gas efficiency�

HyPr-RING Process gasifies an easy-to-gasify portion under

low-temperature (600-700OC) conditions into hydrogen and

uses the remaining hard-to-react char as fuel for CaCO3

calcination.

In such cases, recovery of pure CO2 requires its burning with

oxygen. Fig. 3 shows an example of process configuration with

a fluidized bed gasifier and an internal combustion-type

calcining furnace. For product gas composition of 95% H2 and

5% CH4, the cold gas efficiency proved about 0.76.

Absorbent CaO�

At the gasifier inlet, where temperature is low, CaO first reacts

with H2O to produce Ca(OH)2, providing heat to coal pyrolysis.

Then, at a high-CO2 partial pressure region, Ca(OH)2 absorbs

CO2 to produce CaCO3, releasing heat. This heat is used for

the gasification of char.

To prevent CaO from becoming less active due to high-

temperature sintering, a method of absorbing CO2 by way of

Ca(OH)2 in the furnace is employed. Gasification at a temperature

as low as possible is also employed to prevent eutectic melting of

calcium minerals. In such cases, unreacted product carbon can be

used as a heat source for CaO reproduction.

4.Outline of project�

Under this project that started in 2000, process configuration

identification and FS through testing with batch/semi-continuous

equipment were paralleled with a variety of factor tests required.

In and after 2003, it is expected that 50-kg/d (coal base) continuous

test equipment will be fabricated for continuous testing and then,

based on the results, running tests and FS of a 0.5-1t/d-scale bench

plant are to be carried out in and after 2006 for its established

commercialization process. Table 1 shows development targets of

the project and Table 2 shows, the scheduleof the project.

2.Theory of HyPr-RING Process�

HyPr-RING Process is a process in which a CO2-absorbent CaO

is directly added into the coal gasifier and the CO2 thus produced

is fixed as CaCO3 to finish preparing hydrogen within a furnace.

The reaction between CaO and H2O causes heat so that the heat

necessary for reaction is internally supplied in the furnace as a

great merit from a thermal point of view. Within the furnace, a

series of reactions from Equation (1) to Equation (4) and the

overall reaction of Equation (5) take place.

This overall reaction is an exothermic reaction with C, H2O, and

CaO as starting reactants. This means there is no need of

external heat in theory. It is also found that CO2 fixation shifts

the reactions (2) and (3) to H2 generation.

Fig. 1 shows the process concept of HyPr-RING. Product CaCO3

is reproduced by calcining into CaO for its recycle as an absorbent.

Most of the heat energy required for calcining is carried as

chemical energy of CaO and made available for the reaction to give

H2 in the furnace.

What is difference from Conventional gasification?

Conventional gasification secures the heat necessary for

gasification by partial combustion of coal, with a reaction

expressed by the following equation taking place in the gasifier:

One mole of input coal carbon gives about 1 mole of hydrogen

(including that producible from CO). For this, however,

gasification gas must be sent through a low-temperature shifter

and then exposed to a low-temperature absorbent such as amine

for CO2 separation. At that time, the amount of CO2 gas

separated is 1 mole per mole of hydrogen.

On the other hand, HyPr-RING Process uses dry CaO to absorb

CO2 in the furnace (650OC, 30atm). In this case, heat is released

with CO2 absorption and made available for maintaining high

temperature in the gasifier .

Here, post-CO2 absorption CaCO3 is returned to CaO by

calcination (reproduction) and, at that time, 50-80% of thermal

energy required changes into chemical energy of CaO for reuse

in the gasifier (Fig. 2).

As seen from Equation (5), 2-mol hydrogen production from 1

mol of carbon is another important feature.

Fig. 2 Hydrogen production using HyPr-RING process.

Fig. 3 Analysis of HyPr-RING process

Item Target

Table 1 Targets

Table 2 Development Schedule

1. Gasification efficiency

2. Product gas purity

3. CO2 recovery

1. Cold gas efficiency: 75% or more

2. Sulfur contents of product gas: 1ppm or less

3. High-purity CO2 recovery rate: 40% or more

of input coal carbon to be recovered (per-unit

of energy CO2 exhaust to be less than that

from natural gas)

20102000 2001 2002 2003 2004 2005 2006 2007 2008 2009

(1)Fundamental test

(2)Acquisition of design data

(3)50-kg/d test facility

(4) 500-kg/d PDU

(5)FS

Item

1) Shiying Lin, Zenzo Suzuki & Hiroyuki Hatano, Patent No. 29791-49 (1999)

2) Energy Technology and the Environment, Editors: A. Bisio and S. Boots, John Wiley & Sons, New York, 1995

References

Pilot plant test (moving to the 2nd phase)

Fig. 1 Concept of HyPr-RING process

Mid

-ter

m e

valu

atio

n

Pre

-fin

al e

valu

atio

n

Fin

al e

valu

atio

n

Coal supply1,000t/dHeating value6,690kcal/kg

Cold gas efficiency0.76

Coal 1,000t/d Mixing

Rock hopperCyclone

Heatexchange

Met

hane

refo

rmin

g

Gasifier

Water vapor C

alci

ning

Heat exchange

O2 separation

Steam turbine

In charge of research and development: Center for Coal Utilization, Japan; National Institute of Advanced Industrial Science and Technology; Ishikawajima-Harima Heavy Industries Co., Ltd.; Babcook Hitachi K.K.; Mitsubishi Materials Corporation; JGC CorporationProject type: Subsidized by the Ministry of Economy, Trade and IndustryPeriod: 2000-2010


Masaki Iijima et al, "CO2 Recovery/Effective Utilization/Fixation and Commercialization", MHI Technical Journal, 39(5), 286 (2002)

Reference

85

1.CO2 recovery technology�

(1) CO2 recovery technology (for natural gas, syngas, and

exhaust gas)

CO2 separation/recovery widely prevails in natural gas and syngas sectors

and already has a decades-long history. CO2 contents of natural gas are not

only useless themselves because of making natural gas less caloric but also

trouble LNG/ethane recovery plants by solidifying CO2 into dry ice. CO2 is

hence removed to prevent such troubles.

In a plant where natural gas or naphtha is reformed to manufacture H2, CO2

is separated after converted from the CO produced with hydrogen as

syngas. In an ammonia/urea plant, CO2 is separated from the gas mixture of

H2, N2, and CO2 to produce urea, using H2/N2-derived synthetic ammonia

and separated CO2.

Previously, however, CO2 separation/recovery from exhaust gas was not in

so large demand, finding limited applications only in food/dry ice production.

In case that CO2 is separated from natural gas or syngas, the separation is

relatively easy because of a high gas pressure while CO2

separation/recovery from exhaust gas is difficult in many technological

respects due to a very low level of exhaust gas pressure as well as oxygen,

SOx, NOx, and soot/dust that are contained in exhaust gas.

(2) Necessity to recover CO2 from fixed sources

Most of fossil fuel (oil, natural gas, and coal) in the world is used as fuel

of boilers, gas turbines, and internal combustion engines, releasing

CO2 into the atmosphere as exhaust gas. As a result, it is alleged that

the atmospheric concentration of CO2 has increased to cause the

global warming, which can never be prevented unless CO2 release into

air is mitigated. There are, however, many difficulties in recovering and

sequestrating CO2 from movable bodies such as automobiles and

vessels, naturally rendering it easier to recover CO2 from boilers, gas

turbines, and other fixed sources.

(3) Characteristics and superiority of technology to recover CO2

from exhaust gas

The Kansai Electric Power Co., Inc. and Mitsubishi Heavy Industries,

Ltd. started in 1999 a joint R&D program to recover CO2 from exhaust

gas of power plants and other facilities as a measure against the global

warming. First, they assessed the conventional "monoethanolamine

(MEA) liquid absorbent-based technology considered at that time a

CO2 recovery process that could save the largest amount of energy. It

is a process developed by former Dow Chemical Co. and later

assigned to Fluor Daniel, Inc. This MEA-based technology was found

disadvantageous for use in large plants as a measure against the

global warming because of such problems as a large amount of energy

required for CO2 recovery and a great loss in the liquid absorbent due

to its rapid deterioration. Kansai Electric Power and Mitsubishi Heavy

Industries started with basic research to explore a new liquid absorbent,

resulting in successful development of a novel energy-saving and

uneasier-to-be-deteriorated/-lost liquid absorbent, which has already

been put into practice for urea manufacture in Malaysia.

2.CO2 sequestration technology�

As for methods of CO2 sequestration, geological sequestration and

ocean sequestration are widely studied and a commercial project of the

former has already started.

Geological sequestration of CO2 is practiced, using the Enhanced Oil

Recovery (EOR) method or the coal seam sequestration-accompanied

Coal Bed Methane Recovery method but, if intended only for CO2

sequestration, methods of aquifer sequestration and sequestration into

closed oil/gas fields may also be used. Fig. 1 shows a conceptual view

of CO2 recovery - EOR combination.

CO2-EOR commercialization started in the 1970’s mainly in the United

States, realizing the present enhanced oil production of about 200

thousand barrels a day. Outside the United States, such practice is also

witnessed in Canada, Turkey, and Hungary. In terms of by-application

consumption, EOR purposes are the largest in fact.

Underground aquifers are widely distributed wherever on the earth

sedimentary layers are located. Even in Japan, where aquifers are

scarce and, if any, small in structure because it is a volcanic country and,

therefore, a country of earthquakes, surveys are under way, seeking the

possibility of CO2 sequestration.

If a geological underground layer has cavities, CO2 can be sequestrated

in these cavities, which indigenously contains water (mainly salt water),

by pressing in it there to replace water. This has already started in

Norway. For Japan, Norway-like CO2 sequestration into aquifers

distributed over continental shelves is considered the most realistic.

Other than into aquifers, CO2 can also be sequestrated into closed

oil/gas fields where production had already terminated. Closed oil/gas

fields may, since their ceilings are so geologically structured from ancient

times as not to permit any oil/gas leaks for possible formation of oil/gas

wells, be CO2 containment-secured locations for pressing in CO2

Photo 1 Conceptual View of Practice to Recover CO2 from Power Plant Exhaust Gas for EOR

4C2. CO2 Recovery and Sequestration Technology


Part2 Outline of CCTEnvironmental Protection Technologies (CO2 Recovery Technologies)

Masaki Iijima et al, "CO2 Recovery/Effective Utilization/Fixation and Commercialization", MTI Technical Journal, 39(5), 286 (2002)

Reference


86

1.Urea production�

At present, urea is manufactured by synthesizing ammonia with

inexpensive natural gas as its main material to use this ammonia

with the CO2 derived as off-gas at that time for synthesis of urea.

When urea is synthesized with natural gas as raw material,

however, CO2 may sometimes be short in view of the balance

between ammonia and off-gas CO2. In such cases, CO2 is

recovered from exhaust gas of the steam reformer, which

manufactures hydrogen and CO from natural gas, for the supply

to urea synthesis to adjust the ammonia-CO2 balance, thereby

enabling urea to be produced in largest quantities. The plant

Mitsubishi Heavy Industries, Ltd. delivered to Malaysia

PETRONAS Fertilizer Sdn. Bhd. matches this purpose. Photo 1

shows the appearance of this plant.

2.Methanol production�

Methanol is now also manufactured mainly with natural gas as

raw material. If H2 and CO are synthesized by steam-reforming

natural gas, then the H2:CO ratio is 3:1. On the other hand, for

methanol synthesis, the best H2:CO ratio is 2:1 but the output of

methanol can be maximized through the recovery of CO2 from

steam reformer exhaust gas to add a worthwhile amount of CO2

in carbon contents within the process. At present, active

planning for CO2 addition is under way to improve the production

capacity of Saudi Arabian methanol plants.

Fig. 1 shows a system where, in the process to produce

methanol with natural gas as raw material, CO2 is recovered from

steam reformer exhaust gas to optimize the H2:CO ratio for

methanol synthesis, thereby enhancing methanol production.

4.GTL production�

GTL is the acronym of Gas to Liquid generally referring to a

process to synthesize kerosene and light oil by Fischer-Tropsch

Method (FT Method). For this GTL synthesis, it is necessary to

adjust the H2:CO ratio to 2:1 like in the case with methanol and

the same recovery of CO2 from steam reformer exhaust gas for

its input within the process system as in methanol production

enables the H2:CO ratio to be adjusted.

The method used for the system as a whole, however, recycles

CO2 not contributing to the reaction from FT Synthetic System to

the stream before the steam reformer.

3.DME (dimethylether) production�

DME is currently synthesized by way of methanol. The process

uses a system similar to that for the above-mentioned methanol

production.

4C3. CO2 Conversion Technology


Photo 1 Total view of Plant

Fig. 3 CO2 recovery from exhaust gas-integrated liquid fuel production system

Fig. 2 CO2 recovery from exhaust gas-integrated DME production system

Fig. 1 System to recover CO2 from exhaust gas for enhanced methanoproduction in a methanol plant

Fuel

DMEsynthesis

DME

CO2 recoveryCO2

Exhaust gasNatural gasSteam Steam reformer

Fuel

Syngas compressor

Methanol synthesis

Methanol

Liquid fuel

CO2 recoveryCO2

Exhaust gasNatural gasSteam Steam reformer

Fuel

Syngas compressor

CO2 recoveryCO2

Exhaust gasNatural gasSteam Steam reformer Syngas

compressorMethanol synthesis

FTSynthesis

87

Fig. 1 Comparison of CO2 recovery between oxygen combustion process and ordinary air combustion process

Coal

Coal

Air

Stack

CO2 separation and recoveryDesulfurizationDust removalBoiler

Recovery process using oxygen combustion

Flue gas recycleO2/CO2

Air Air

separatorDust removalBoiler

4C4. Oxy-fuel Combustion (Oxygen-firing of conventional PCF System)



Efforts of reduction in CO2 emissions have been promoted over the

world responding to the issues of global warming in recent years.

Specifically, coal is known as a source of heavy emissions of

environmental loading substances (SOx, NOx, CO2, etc.), though

the coal is expected as a sustainable energy resource also in the

future. Since coal generates large quantity of CO2 per unit calorific

value, research and development of the CO2 recovery and CO2

separation technologies are in progress on various points of views.

With the background, the study team focused on the development

of technology to recover CO2 from coal-fired power plants utilizing

oxygen (O2/CO2) combustion, and has promoted the research of

CO2 recovery technology. The CO2 recovery in the oxygen

combustion stage is a hopeful technology of direct CO2 recovery

from large scale coal-fired power plants.

Ordinary coal-fired power plants combust coal by air. Since air

contains N2 by 79%, all of the N2 is emitted to atmosphere during

the combustion process, thus the CO2 concentration in the

combustion flue gas is only 13-15% level. The oxygen combustion

technology is a process to separate oxygen from the combustion

air and to directly combust the coal with thus separated oxygen to

increase the CO2 concentration in the flue gas to 90% or more,

then to recover the flue gas in that state (refer to Fig. 1.)

Furthermore, the study team investigated a CO2 recovery system

applying oxygen-blow IGCC aiming to further increase the

efficiency.

In charge of research and development: Center for Coal Utilization, Japan; Electric Power Development Co., Ltd.;Ishikawajima-Harima Heavy Industries, Co., Ltd.; Nippon Sanso Corp.; and Institute of Research and InnovationProject type: Coal Production and Utilization Technology Promotion GrantPeriod: 1992-2000 (8 years)

Ordinary recovery process

RecoveredCO2

RecoveredCO2

Compressor

Compressor

2.Result of the development�

Efforts of reduction in CO2 emissions have been promoted over the

world responding to the issues of global warming in recent years.

Specifically, coal is known as a source of heavy emissions of

environmental loading substances (SOx, NOx, CO2, etc.), though

the coal is expected as a sustainable energy resource also in the

future. Since coal generates large quantity of CO2 per unit calorific

value, research and development of the CO2 recovery and CO2

separation technologies are in progress on various points of views.

With the background, the study team focused on the development

of technology to recover CO2 from coal-fired power plants utilizing

oxygen (O2/CO2) combustion, and has promoted the research of

CO2 recovery technology. The CO2 recovery in the oxygen

combustion stage is a hopeful technology of direct CO2 recovery

from large scale coal-fired power plants.

Ordinary coal-fired power plants combust coal by air. Since air

contains N2 by 79%, all of the N2 is emitted to atmosphere during

the combustion process, thus the CO2 concentration in the

combustion flue gas is only 13-15% level. The oxygen combustion

Part2 Outline of CCTEnvironmental Protection Technologies (CO2 Recovery Technologies)


88

1) Hiromi Shimoda: Proceeding of the 10th Coal Utilization Technology Conference, p.211 (2000)

2) S. Amaike: Proceeding of the 5th ASME/JSME Joint Thermal Engineering Conference, "AJTE99-6410" (1999)

Fig. 2 Image-drawing of CO2 recovery type power plant applying oxygen combust

H2O

N2H2

CO2

N2

Recovered CO2

Bleed

Gasification Gas purification CO-shift reaction CO2 removal HRSG

CO2

compression

Coal

Air Air

Steam

CO

CO2

H2

H2O

CO2

H2

Air separation

Air combustion gas turbine

3.Issues and feasibility to practical application�

Regarding the CO2 recovery type oxygen combustion power

generation system and the CO2 recovery type IGCC, the study

team conducted research and development and has proposed a

power generation system which has superiority in terms of

performance and economy as a CO2 recovery technology. In

addition, in the basic combustion test, the study team has acquired

academically valuable results (including the effect of reduction in

NOx emissions).

It should be emphasized to further promote the study for controlling

the global warming and for reducing the CO2 emissions, though

there are technologically validating issues such as the safety of

power generation system with the oxygen combustion and the

operability of CO2 recovery type IGCC. As for the practical

application of the system, positive study should be conducted on

the basis of the obtained results, while studying the application of

the CO2 recovery type oxygen pulverized coal combustion system

and of the CO2 recovery type IGCC, respectively, for the cases of

application of CO2 recovery to an existing plant and of new plant.

References

CO2 recovery type oxygen pulverized coal combustion power plant

CO2 underground disposal

CO2 ocean disposal

CO2 tank

Oxygen production facility

Boiler

Fig. 3 CO2 recovery type IGCC system

technology is a process to separate oxygen from the combustion

air and to directly combust the coal with thus separated oxygen to

increase the CO2 concentration in the flue gas to 90% or more,

then to recover the flue gas in that state (refer to Fig. 1.)

Furthermore, the study team investigated a CO2 recovery system

applying oxygen-blow IGCC aiming to further increase the

efficiency.

Basic Technologies for Advanced Coal Utilization

89

The consumption of fossil fuel compacts on the environment in a

variety of manners. Coal also influences the nature in each of its

production, transportation, and utilization processes. In the

process of its utilization in particular, coal dust, ash dust, acid gas

(NOx, SOx), and carbon dioxide are discharged, suggesting that

unregulated guzzling of coal may possibly have a great impact on

the environment. On the other hand, technologies to limit the

impacts derived from coal utilization on the environment to the

minimum, as measures to cope with the above-mentioned

situations, were collectively called Clean Coal Technology (CCT),

for which advanced R&D is in wide practice in major advanced

countries including Japan.

With such circumstances , the "Basic Technology Development

Program for Advanced Coal Utilization (BRAIN-C)," mainly

targeting at the coal gasification technology and to realize early

commercialization of new high-efficiency and clean coal

utilization technologies such as coal gasification and pressurized

fluidized-bed processes, has sought and accumulated basic data

on coal from different angles. In the meantime, numerical

simulation is a very effective tool to predict characteristics of a

pilot or actual production unit from the above-mentioned basic

data or, in reverse, to evaluate and select useful basic data. With

this taken into consideration as well, technology development

under the BRAIN-C is proceeded with from both aspects of useful

basic data retrieval/storage and high-precision numerical

simulation.

Fig.1 shows "BRAIN-C Technology Map." Products from this

project are roughly grouped into the following three categories:

�(1) Entrained flow gasification simulator

�(2) Predicted model/parameter correlative equation

�(3) Coal database

Each category is explained below. Every categories, as integral

part of products from this project, is indispensable for their actual

use in a variety of situations, and ingenious utilization of each in

accordance with the situation where it is used allows such

products to be given full play.

Fig. 1 BRAIN-C Technology Map

5A1. Modelling and Simulation Technologies for Coal Gasification


1.Outline of basic technology for advanced coal utilization (BRAIN-C)�

�

In charge of research and development: Center for Coal Utilization, JapanProject type: NEDO-commissioned project

Volatile contents release data

Volatile contents database

Char reaction dataReaction database

Coal PhysicalityPhysicality database

(coal and char)+General analysis

+Particle size-surface area+Special analysis

CCSEM, XRD, EDS

Heat transmission coefficient

Heat transmission test data

Particle radiation data

Parameter correlative equation

Radiation parameter

Particle size-

density fluctuation model

Volatilization model

Gasification simulation code

+ RESORT+ FLUENT

Adhesion judgment equation

Adhesion data

Trace element data

CPC actual measurement data

Basic database

Trace element distribution model

ProgramEquilibrium model

Growth flowagejudgment model

Typical temperature history

Volatile contents composition in quantity

Reaction temperature constant

Typical

temperature data

Typicaltemperaturedata



90

Fig. 2 Functions of Entrained-Flow Gasification Simulator

Fig. 3 Coal Gasification Process Modeling

2.Entrained flow gasification simulator�

An entrained flow gasification simulator based on the thermal

fluid analysis software (CFD) capable of analyzing flow, reaction,

and heat transmission at the same time can calculate

temperature distribution, ash adhesion locations, gas

composition, etc. within a gasifier if given as input data such

parameters as reactor shapes, operation conditions, coal

property and reaction data. It is imaged in Fig. 2 as "Functions

of an Entrained Flow Gasification Simulator." Highly reliable

prediction results can be used for evaluating operational

condition validity, reactor design, and others in advance. The

BRAIN-C, developing a coal gasification reaction model shown in

Fig. 3 and a particle adhesion model shown in Fig. 4 in basic

CFD, has compared their calculation results with gasifier

operation data in coal-based hydrogen production technology

(HYCOL) to verify the adequacy.

Fig. 4 Ash viscosity-Based Adhesion Judgment Model

Simulation program(For entrained-flow gasification)

Ash adhesion position Temperature distribution CO concentration

Pre-test judgment of operational validity

Design: Furnace shapeOperation: Operational conditionsCoal: Property

Particle viscosityParticle adhesion judgment conditions

Judgmentvalue

Reflection

Judgmentvalue

Adhesion

Wall ash layer viscosity

Gasification speedGasification database

Volatile contents release speed

Volatile contents

Fixed carbon

Fixed carbon

Ash

AshAsh

Gas-phasereaction

Oxidizing agent

Product gas

Basic Technologies for Advanced Coal Utilization

91

Fig. 5 shows an example of results from comparison between

the formation position of fused ash layer and the internal

condition of gasifier after operations. This found the formation

position of fused ash layer calculated with this simulator well-

corresponding to the position where the fused ash layer actually

existed, endorsing the adequacy of calculation with actual data.

Fig. 6 shows the result of case studies on HYCOL using

gasification simulation. The near-wall temperature and ash

viscosity on the wall shown on the left side of Fig. 6 are those

reproduced by calculation under the condition after 1,000-hour

operation . The temperature of the furnace bottom area (in red

color) onto which slag flows down is found high against the low

ash viscosity in the region (in blue). The temperature of the upper

furnace part proves low (in green), giving conditions where

particles can hardly adhere. On the other hand, the wall-near

temperature and ash viscosity on the wall shown on the right side

of Fig. 6 are from the result of calculation under operational

conditions changed intentionally. For this case, the oxygen ratio

of the chart top is higher and that of the bottom is lower than

shown on the right side of the figure. In such cases, it was found

that the temperature of the furnace bottom area goes down (in

orange color) and the low-ash-viscosity region (in blue) narrows

while the upper furnace part becomes hot (the region in red

increases) to form a region where ash is easier to adhere,

probably spoiling the operating conditions.

In this way, using the gasification simulator, analysis can be

easily made even if gasification conditions are altered and,

therefore, an expectation is growing on its utilization in future

gasification projects.

Fig. 5 Ash Adhesion Position Verification Result Fig. 6 Simulator-Based Studies

3. Predicted model/parameter correlative equation�

An entrained-flow gasification simulator is generalized against

various furnace shapes and operational conditions but not

against each coal characteristics. It is, therefore, necessary to

input such characteristics into the simulator as a parameter by

types of coal. This parameter generally uses the data obtained

from basic test equipment but, in view of quick evaluation, it is

desirable to establish a means to obtain parameters from

general analysis of coal or structural physicality data (an

advanced model referring as far as to predicted correlative

equations and experiment conditions). More specifically, a

generalized volatilization model and the adhesion judgment

equation are among the tools to prepare parameters. In the

meantime, a trace elements distribution model and an adhesion

judgment equation model are models making judgments from

simulation results, playing another important role. Under the

BRAIN-C, thus, prediction equations around a gasification

simulator have also been developed so that the simulator can be

used effectively and quickly.

Temperature: high

Temperature: low

The low-viscosity region of the top expands.

A high-viscosity region of the

bottom appears.

Case 3 Forecast value

Growth of slag

Throttled section

Pressure detection terminal

Molten slag

Amount of adhesion = amount of slag discharged


Wall-near temperature

Ash viscosity on the wall


92

4.Coal Database

The development of a correlative equation or a model

indispensably requires physical and basic experiment data,

including general analysis data. There is, however, a big problem

that coal is different in characteristics for different lots arrived

even if its brand (name of the coal mine) is the same. It was,

therefore, first necessary for each of testing bodies, where

physical and basic data were obtained, to use completely the

same samples of coal. Fig. 7 shows a coal sample bank installed

within the National Institute of Advanced Industrial Science and

Technology. Such unified management of analytical test samples

has materialized the shipment of identical samples to all testing

research bodies.

As far as these identical sample-based data are concerned, the

measurement of typical data will be completed under this project

on 100 kinds of coal for general/special analysis data and, at

least 10 kinds of coal, depending upon data items, for basic

experiment data. Eventually, all of these measurement data are

to be contained in the Internet-accessible coal database. Some

of the data so far obtained have already been uploaded to the

server of CCUJ for available access or retrieval as shown in Fig.

8. Many of these data are stored in an easy-to-calculate/process

Excel file (see Fig. 9) and can also be downloaded.

AAn entrained-flow gasification simulator so far developed under

the BRAIN-C is capable of making practical predictions through

the utilization of various models and basic data. The BRAIN-C

Project, soon to meet its final year in 2004, is developing a well-

equipped system to make a wide choice of programs and basic

data available so that you can use the products developed under

this project to your hearts’ content. We are also preparing

detailed service manuals as well as giving workshops for this

purpose to encourage your ingenious utilization of these

products.

Despite the coal gasification technology’s predominance in this

development project, those outside gasification projects are

strongly invited as well to use our simulation code, at least, since

it can be widely used in combustion and other sectors.

Fig. 7 Coal Sample Bank

Standard Sample Coal Storage Status (AIST)

Standard Sample Coal (for delivery)

5.Diffusion of basic coal utilization technology products�

�

Fig. 8 Coal Database Fig. 9 Basic Data Acquisition

50-liter container

Reaction data, etc.

On-line retrieval

Reaction data, etc.

Spreadsheet fileDownload

100 kinds of coal

General analysis/special analysis

Reaction data, etc.

On-line retrieval

Reaction data, etc.

Spreadsheet fileDownload

100 kinds of coal

General analysis/special analysis

20-liter container (two-shelf)

Coproduction System

93

6A1. Co-generation System


Fig.1 Typical Outline of a Diesel Engine/Gas Engine Co-generation System1)

Cooling water heat exchanger

Steam

Electricity

1.Definition of co-generation�

The system which continuously takes out two or more sources of

secondary energy such as by burning fuel (primary energy) to

convert it into electricity and heat is called a co-generation

system.

2.Co-generation system�

Co-generation systems are roughly divided into two types. One

is a type which turns a diesel engine, gas engine, gas turbine, or

other motor to generate power while recovering waste heat of the

motor as hot water or steam through the thermal exchange at a

boiler, etc. and the other generates power by rotating a steam

turbine with the steam produced at boilers and, if necessary, take

out steam of desired pressure as process steam.

The former generally uses liquid or gas fuel and is often found as

small-scale equipment for hotels, supermarkets, and hospitals.

As for the latter, every type of fuel including coal is used as fuel

for boilers and many are found as relatively large-scale industry-

use thermal power plants. Systems are further grouped into ones

mainly to supply electricity (condensing turbines) and the others

mainly for steam (heat) supply (back pressure turbines).

3.Efficiency�

In general, the power generation efficiency of a coal thermal

power generation plant which takes out only electricity is around

40%. On the other hand, the overall thermal efficiency of a co-

generation system, which combines its power generation

efficiency and heat recovery efficiency, depends upon whether it

is mainly to supply electricity or mainly to supply heat, with a level

of as high as 80% achieved by the co-generation system mainly

for heat supply.

(1)Co-generation at a large-capacity coal thermal power plant

Kobe Steel’s Kobe Power Plant, a large-scale coal thermal power

plant of 1,400MW (700MW x 2 generators) in capacity, has

commenced its electricity wholesale/supply activities as an

independent power producer (IPP). Electric power products from

No. 1 Unit already in operation from April, 2002 and No. 2 whose

start of operation is slated for April, 2004 are all to be delivered to

the Kansai Electric Power, Inc.

(2)Regional supply of heat

The steam to be used for power generation is partially taken out

for the supply of maximum 40t/h to 4 nearby sake-brewers. This

amount, accounting for about 2% of the steam generated at

boilers, proves that the share of heat supply is small. The steam

generated at multiple boilers of each brewer has so far been put

Diesel or gas engine

Waste heat recovery boiler

Generator Stack

Electricity

Heating

Hot water supply

Process steam

Hot waterJacket cooling water



94

Full View of Power Plant3)

Fig.2 Outline of Heat Supply Facility4)

1) Shibamoto et al: Featured Thermal Power Plant Thermal Efficiency Improvement, Article 3 Thermal Efficiency Management Trend;

Thermal Control for a Power Generation System pp1242-1246, Vol. 54, No. 565, Thermal/Nuclear Power Generation (Oct., 2003)

2) The Thermal and Nuclear Power Engineering Society: Introductory Course IV. Industrial-Use Thermal Power Facilities, Etc. pp1539-

1546 Vol. 54, No. 567, Thermal/Nuclear Power Generation (Dec., 2003)

3) Kida et al: Outline of Power Generation Facilities at Kobe Steel’s Kobe Power Plant pp2-7, Vol. 53, No. 2, Kobe Steel Technical Report (Sept., 2003)

4) Miyabe et al: Kobe Steel’s Kobe Power Plant Surplus Steam-Based Heat Supply Facility pp14-18, Vol. 53, No. 2, Kobe Steel Technical Report (Sept., 2003)

References

together at the header to be sent to a plant. At present,

however, with the header as a point of competitive taking,

steam extracted after working at turbines is directly supplied to

brewers in an attempt to save energy in the region as a whole.

(3)Heat supply conditions

Turbine extraction steam from a power plant, since it contains

trace amounts of hydrazine as an antirust, cannot be directly

supplied to brewers with a process where steam directly

contacts rice. The steam (secondary steam) produced

indirectly, using a steam generator operated with turbine

extraction steam (primary steam) as the heat source, is supplied

to brewers. The outline of a facility is shown in the right.

Steam

BoilerTurbine Generator

Cooling water(Sea water)

ExtractedSteam

Feed water

Primary steam

Industrialwater tank

Sawanotsuru

Fukumusume

Hakutsuru

Gekkeikan

Brewing companies

Secondary steam

Drain cooler

No.1 power plant

BackupNo.2 power plant

Steamgenerator Industrial

water

Water supply processing

Part2 Outline of CCTCoproduction System

95

6A2. Coproduction System


Conventional work for developing innovative process within a

single industry faces a limit. To continue further reduction in CO2

emissions, it is necessary to give full scale review of the existing

energy and materials production systems and to develop

technologies that optimize the individual processes and the

interface between processes not only to improve the conversion

efficiency and to save energy but also to fundamentally and

systematically change the energy and materials production

systems.

The "fuel coproduction power generation system" which

produces power, fuel, and chemicals from coal improves the total

energy use efficiency through the unification of industries by

structuring a coal industrial complex.

In the fields of power, iron and steel, and chemicals where large

amount of coal is consumed as the energy source, structuring a

core plant which produces energy and chemicals simultaneously,

and assembling peripheral plants to produce various products

enhance the unification of industries centering on the core plant,

thus forming a coal industrial complex on the new energy and

materials production system. As a result, the current industrial

style progresses to the next generation hybrid industrial style

through the unification of industries.

The core technology of that type of fuel coproduction power

generation system is the coal gasification technology. By

combining the high efficiency power generation system such as

IGFC with a process to co-produce storable fuel, the

normalization of load to gasification reactor and the significant

reduction of CO2 emissions are attained.

Furthermore, waste heat source in the coal industrial complex is

utilized to recover chemicals from coal while conducting

endothermic reactions, thus forming further high energy

efficiency and upgraded coal industrial complex.

Coal + Biomass(Waste, waste plastics, oil-base residue, etc.)

CoalH2,CO

H2,CO

CH4

BTX, etc.

H2,CO

Steam

Non-reacted gas

PropyleneC2 distillateC4 distillate

H2

H2Coal

Existed or new facilities steam boiler

Fluidized bed gasification furnace

for Fuel cell power generation, for Refinery, for Chemical plant

DME market

for Petrochemical plant

for Iron works

ST

GT

FC

Process steam

fual for heating

for Hydrogen production

for Hydrogenation and desulfurization at iron works

DME

Power

for Petrochemical plant

Petrochemical plant, gas company

Spouted bed gasification furnace

Thermal decomposition furnace

Gasification Center

Fig.1 Energy Flow

1.Feasibility of fuel coproduction power generation system�

�


96

3. Coproduction system�

The coproduction system produces both materials and energy to

significantly reduce the exergy loss which occurred mainly in

combustion stage, and to achieve innovative and effective use of

energy.

That is, the coproduction system is a new production system

which is not only the conventional system which aims to improve

the energy conversion efficiency and the cogeneration system

which effectively uses the generated thermal energy as far as

possible but also the system to produce both energy and

materials to significantly reduce the consumption of energy and

materials. By making the coproduction system clean, energy

issue and the environmental issue are simultaneously solved and

it should activate economy. Consequently, the coproduction

system that conducts production of energy such as power and

fuel while producing materials shall be emphasized from the

viewpoint of creation of new energy market and also of creation

of new industries.

The coal coproduction system centering on the coal gasification is

able to solve the environmental issues through the significant

reduction in CO2 emissions by realizing high grade and

comprehensible coal utilization technology. That type of system

technology development triggers the technological innovation in

the coal utilization field, and the strong innovation is expected to

increase the international competitive power and to encourage the

structuring circulation-oriented society. Also in the international

society, the development of the coproduction system should be an

important technological issue to solve the global environmental

issues.

2. Co-produced fuel and raw materials for chemicals�

Regarding the fuel and chemicals produced along with the power

through the coal gasification, there are typical examples of

coproduction by coal gasification in abroad, depending on the

need of relating companies: the production of synthetic fuel

(GTL) etc. by SASOL group in South Africa; and the production of

acetyl chemicals by Eastman Chemical Company in USA. Other

examples of chemicals synthesis by coal gasification include the

production of methanol, and of methane, in China, Europe, and

the U.S. There are further expectations in producing:

DME which is applicable to the raw material for clean fuel and for

propylene production;

Hydrogen which is expected to increase the demand for the fuel

of fuel cells and for coming hydrogen-oriented society; and

Clean gas for iron works which responds to the changes in

energy balance at future iron works.

Power generation in existing steam turbine power generation system

Fuel for power generation

fuel for heating

Coal yardWaste

Fluidized bed gasification reactor

Shift reaction

Iron works Petroleum industrial complex

Process steamfuel for heating

Gas,Power,Steam,BTX, etc.

IGCC for industrial complex areaPrivate power generation at iron works GT-CCCo-operative Thermal Power Company GT-CC

Spouted bed gasification reactorThermal decomposition reactor

Residue oil

Gas

Power

Fuel

Steam

for Hydrogenation

Un-recovered gas

H2 separation DME production

H2/CO > 2

Hydrogen

Outside sale

Outside sale

Non-reacted gas

Recovered steam

Fig.2 Power generation, steam, fuel for process heating, hydrogen, DME, energy supply system in iron works

(The total efficiency of the coproduction system unified with the iron works is estimated to increase from the current level by about 14%, and the unit requirement of CO2 emissions is expected to decrease by about 17%.)

GasPower Steam BTX, etc.

Part3 Future Outlook

97

Future Outlook for CCT

If we examine the future of Clean Coal Technology from the

viewpoint of technical innovation in the coal utilization sector, we

may find a technological trend that is, as mentioned below,

crucial for society as well as full of diversity.

The trend may be separated into three main directions in terms of

key technology development systems. The first direction is

already seen in two deployment programs now under way which

focus on coal gasification technology; one for high-efficiency

power generation systems, whose commercialization process is

steadily progressing, including "Coal-fired Integrated Gasification

Combined Cycle (IGCC)" and "Coal-fired Integrated Gasification

Fuel Cell Combined Cycle (IGFC)" and the other for "conversion

into liquid fuel and raw material for chemicals" which contains no

impurities, such as methanol, DME, or GTL. Moreover, these

technologies will give rise to a zero emission-oriented world of

"co-production" including co-generation.

The second direction is future energy sector advancements to

cope with the likely realization of "hydrogen energy communities."

According to IIASA 2000 (International Institute for Applied

System Analysis 2000), analysis showed that global primary

energy consumption was on a near-constant increase between

the middle of the 1800’s and around 1980 in terms of "H/C

(hydrogen/carbon)" ratio. In and after 1980, it remained almost

unchanged at around H/C = 2 due to an increase in oil

consumption. As a whole, however, the trend before 1980 is

expected to resume, inviting the situation of H/C = 4 around

2030. In such a society of transition from natural gas to

hydrogen, final energy consumption by carbon combustion will be

discouraged, even predicting the advent of a situation where coal

energy could be used only in the world of HyPr-RING (Hydrogen

1 9 6 0 1 9 7 0 1 9 8 0 1 9 9 0 2 0 0 0 2 0 1 0 2 0 2 0

60

55

50

45

40

35

Start of operation yearPla

nn

ed

gro

ss t

he

rma

l eff

icie

ncy

(H

HV

% )

Fig.1 Change in LNG and Coal Thermal Power Generation Efficiency

Coal-fired IntegratedGasification Fuel Cell

Combined Cycle (IGFC)

LNG-fueled Gas TurbineCombined Cycle (ACC)

(1,700oC-class)

Coal-fired Integrated GasificationCombined Cycle (IGCC)

(1,500oC-class)

Prepared from High-Efficiency Power Generation Technology Review Meeting Report (Jan., 2003) of the Institute of Applied Energy

LNG steam power generation

LNG-fueled Combined Cycle (ACC)

Coal-fired steam power generation

Coal-fired Integrated GasificationCombined Cycle (IGCC)

100.0

10.0

1.0

0.11800 1850 1900 1950 2000 2050 2100

H/C

Prepared from IIASA 2000

Hydrogeneconomy

Methane economy

Coal: H/C = 1

Oil: H/C = 2

Gas: H/C = 4

Dissolutiondiffusion

Fig. 2 Various CCT developments centering on coal gasification

Hybrid gasification of coal, �biomass, waste plastics, etc.

Biomass

Coal

Gasification furnace

Oil

Reduced iron Iron and steel

Blast furnaceStorage

Effective use

Gas oil, naphthalene, etc.

Methanol, acetic acid, etc.

Chemicals

Blast furnace

Synthesis gas (H2, CO)

Hydrogen station

H2CO2

Stationary fuel cell

H2 production, CO2 �separation and recovery

Commercial, �transportationCommercial, �transportation

DME,GTL

IGCC/IGFCElectric power

BoilerBoiler

Coproduction manufacturing also �raw materials for chemicals

Coproduction manufacturing also �reduced iron

Slag

GasificationGasification

Waste plastics

Power plant, automobiles, etc.Power plant, automobiles, etc.

Fuel cell vehicle

Blast furnace

Advanced gasification �furnace

Waste, waste plastics

Fig. 3 Trend of ratio of hydrogen to carbon (H/C) in the primary energy

98


Production by Reaction Integrated Novel Gasification Process,

where H/C approximates one) and society will be forced to

depend largely upon separating and retrieving CO2 generated by

the direct combustion of coal and the technology to separate and

sequester CO2. High-efficiency coal utilization technology to

separate/recover and then sequester/store direct combustion-

derived CO2 or reduce CO2 emissions by using carbon

components of coal as fuel or raw material for chemicals by way

of coal gasification and reforming/conversion, presents important

challenges to Clean Coal Technology.

The third direction is latently potential development of coal

utilization technology in conjunction with each of four technology

sectors given priority for development in Japan, namely,

environmental/energy, bio-, nano-, and information technology

sectors.

Emphasis is placed on environmental/energy technology

development, as mentioned earlier, toward the realization of a

zero-emission society mainly through the implementation of "CO2

countermeasures," and the co-production system is regarded as

being the target such technical innovation must achieve.

Advancements in biotechnology could also unlock methods for

the fixation and effective utilization of CO2.

Furthermore, hyper-coal production technology development will

lead to processes for the advanced utilization of the carbon within

coal. In fact, technological innovation in the nano-technology

sector is anticipated to lead to such as nano-carbon fibers.

JoulCok

ing p

roce

ss

Liquefaction/

Pyrolysis process

Gasification/

Conbustion process

Pow

er plant

Coal (solid fuels)

Air/water

Raw material

Electricity

Heat (steam/

hot water)

Fuel (gas/liquid)

Hydrogen

Waste heatDrainageExhaust

Steel Chemicals CementOther

by-products

Environmental facility

Chemical plant

Steel-making plant

Cemen

t plan

t

Light energy

Dynamic energy

Chemical energy

Electric&magnetic energy

Heat energy

Energy conversion system

Fig.6 co-production systemThe ultimate goal of a co-production system lies in zero emissions (or the state of purified water and steam discharged )

Separation/recovery

Pressure injection from a facility on the sea

Tanker transport

Pipeline carriage

Underground aquifercoal bed

Pressure injection froma ground facility

Sequestration/storageSeparation/recovery Gas after decarburizedCO2 concentration 2%

Separated/recovered CO2 concentration

99%

Discharged CO2 concentration

22%

Sources from which CO2 is discharged

(including power and steel plants)

-Chemical absorption method-Physical absorption method-Membrane separation method

Separation/recovery Transportation Sequestration/storage

Aquifercoal bedDissolution/diffusion or as hydrates (onto the sea bottom)

-Ground:

-Sea:

Pipeline after liquefied (long-haul)Liquefied CO2 transport vessel

-Underground:

-Ocean:

CO2

CO2

Cap rock (impervious layer)



Fig. 5 Future energy-oriented society supported by CCT, (2030)

Commercial, �transportation

Boiler

Gasification

Power plant, automobiles, etc.

Fuel cell vehicle

Coal gasification

Electric power

Iron and steel

Energy and materials linkage between industries

Power plant

USC IGCC IGFC

Iron and steel works

Chemicals, �otherHydrogen station

Biomass

CoalReformed coal

Blast furnace


Blast furnace


Coal partial hydrogenation

Hyper ring

USBCO2 isolation

CO2 recovery

SCOPE21

Waste, waste plasticsWaste, waste plastics

Fig. 4 CO2 Separation, recovery, isolation, and storage

99

CCT has an important role in the power generation as well as in

the steelmaking sector, where coal functions not only as an

energy source but also as a high-quality reducing agent. A

potential task to be assigned to well-established steelmaking

processes (e.g. blast-furnace process) is achievement of an

innovative level of total coal utilization efficiency, using a co-

production system like DIOS (Direct Iron Ore Smelting reduction

process) to simultaneously produce iron and synthetic gas,

electric power, hydrogen/thermal energy, raw material for

chemicals, etc. from steam coal for steady implementation of

improved environmental measures toward zero emissions.

As the global leader in coal imports as well as a leader in Clean

Coal Technologies, Japan must remain active in international

cooperation mainly in Asia for human resources development,

technology transfer, and other relevant activities. Such

international cooperation may possibly serve not simply those

countries dependent upon coal energy for their economic growth

but as an important measure to address global environment

issues through the extensive influence of the Kyoto Mechanisms,

particularly CDM (Clean Development Mechanism).

Economic growth indispensably requires a stable supply of

energy while environmental preservation is a problem that

should be tackled on a global scale, considering the

interdependent relationship between the two. Underlying both,

current population growth is both explosive and unprecedented.

Efforts toward zero emissions to protect the environment must

be assigned top priority in the development of Clean Coal

Technologies in Japan. A further obligation, beyond international

cooperation activities, is to continuing development of an efficient

and advanced coal utilization system to minimize impact on the

global environment.

It has become necessary for us, presently positioned to

undertake technology development in one of the energy-related

sectors given top priority, to further concentrate efforts in an

attempt to devise innovative Clean Coal Technologies for the

establishment of an affluent, clean, and comfortable society

where economic growth is compatible with the environment.


Part3 Future OutlookFuture Outlook for CCT

Promotion of innovative CCT development toward the actualization of "Zero-emission"

Aiming to position the coal as a source of CO2-free energy by 2030, the project positively promotes the innovative CCT development including the CO2 fixation technology and the next-generation high efficiency gasification technology toward the actualization of "Zero-emission", while identifying the position of individual technologies in the total schedule.

Air-blow �gasification

Oxygen-blow �gasification

Improvement in the thermal efficiency Unification with CO2 separation �and fixation technology

Unification with CO2 separation �and fixation technology

Demonstration test

Demonstration test

Demonstration test

Demonstration test

Demonstration test of new separation �and recovery technology

Demonstration test

Development toward the full scale storage

F/S

Research and �development

Research and development


Research and developmentResearch and development

GCC commercial �unit

46-48% sending end efficiency55% sending end efficiency


>65% sending end efficiency>65% sending end efficiency

GFC commercial �unit

A-IGCC�/A-IGFC

6 yen/kWh 6-7 yen/kWh

Industrial gasification �furnace

Actualization of Zero-emission

Zero-emission

Advanced coal �gasification

CO2 separation �and recovery

CO2 fixation

Co

al gasificatio

n tech

no

log

yFixation technology

* Current coal thermal generation unit price is assumed to 5.9 yen/kWh which is estimated by The Federation of Electric Power Companies Japan.

Timing of commercialization

100

Clean Coal Technologies in Japan New Energy and Industrial Technology Development Organization (NEDO)Muza Kawasaki Central Tower 16F, 1310, Omiya-cho, Saiwai-ku, Kawasaki-shi, Kanagawa 212-8554Tel. 044-520-5290Fax. 044-520-5292Center for Coal Utilization, Japan (CCUJ)Sumitomogaien Bldg 7F, 24, Daikyocho, Shinjuku-ku, Tokyo 160-0015Tel. 03-3359-2251Fax. 03-3359-2280

(1) Main SI units

(3) Typical conversion factors

(5) Standard heating value for each energy source

(4) Coal gasification reactions

(2) Prefix of SI system

kgkgkgkgkgkg

kgNm3

Nm3

Nm3

kg

kg

kgNm3

kgNm3

Nm3

kWh

kWh

kg

28.9 MJ29.1 MJ28.2 MJ26.6 MJ22.5 MJ27.2 MJ

30.1 MJ21.1 MJ3.41 MJ8.41 MJ

38.2 MJ35.3 MJ

50.2 MJ34.1 MJ34.6 MJ36.7 MJ36.7 MJ38.2 MJ39.1 MJ41.7 MJ40.2 MJ42.3 MJ

35.6 MJ44.9 MJ

54.5 MJ40.9 MJ

41.1 MJ

9.00 MJ

3.60 MJ

2.68 MJ

6904 kcal6952 kcal6737 kcal6354 kcal5375 kcal6498 kcal

7191 kcal5041 kcal 815 kcal

2009 kcal

9126 kcal8433 kcal

11992 kcal8146 kcal8266 kcal8767 kcal8767 kcal9126 kcal9341 kcal9962 kcal9603 kcal

10105 kcal

8504 kcal10726 kcal

13019 kcal9771 kcal

9818 kcal

2150 kcal

860 kcal

641 kcal

7600 kcal

6200 kcal5800 kcal6500 kcal

7200 kcal4800 kcal

800 kcal2000 kcal

9250 kcal8100 kcal

12000 kcal8000 kcal8400 kcal8700 kcal8900 kcal9200 kcal9300 kcal9800 kcal9600 kcal

10100 kcal

8500 kcal9400 kcal

13000 kcal9800 kcal

10000 kcal

2250 kcal

860 kcal

1018

1015

1012

109

105

103

102

1010-1

10-2

10-3

10-6

10-9

10-12

AngleLengthAreaVolumeTimeFrequency, vibrationMassDensityForcePressureWork, energyPower Thermodynamic temperatureQuantity of heat

1. basic Energy Units 1J (joule )=0.2388cal 1cal (calorie )=4.1868J 1Bti (British )=1.055kJ=0.252kcal2. standard Energy Units 1toe (tonne of oil equivalent )=42GJ=10,034Mcal 1tce (tonne of coal equivalent )=7000Mcal=29.3GJ 1 barrel=42 US gallons 159l 1m3=35,315 cubic feet=6,2898 barrels 1kWh=3.6MJ 860kcal 1,000scm (standerd cubic meters ) of natural gas=36GJ (Net Heat Value ) 1 tonne of uranium=10,000~16,000toe(Light water reactor, open cycle) 1 tonne of peat=0.2275toe 1 tonne of fuelwood=0.3215toe

radmm2

m3

s (Second )Hz (Hertz )kgkg/m2

N (Newton )Pa (Pascal )J (Joule )W (Watt )K (Kelvin )J (Joule )

…(degree ), ’(minute), ’’(second)

(liter)d (day), h (hour), min (minute)

t(ton)

bar (bar)eV (electron voltage)

ExaPetaTeraGigaMegakilo

hectodecadecicentimilli

micronanopico

EPTGMkh

dadcmunp

PrefixQuantity SI unit Unit applicable with SI unitName

Multiple to the unitSymbol

Energy source

March 15, 2004

Standard heating valueUnit Standard heating value (as kcal) Old standard heating value Remark[Coal]�Coal Imported coking coal Coking coal for Coke Coking coal for PCI Imported steam coal Domestic steam coal Imported anthraciteCoal product Coke Coke oven gas Blast furnace gas Converter gas

[Oil]Crude oil Crude oil NGL, CondensateOil product LPG Naphtha Gasoline Jet fuel Kerosene Gas oil A-heavy oil C-heavy oil Lubrication oil Other heavy oil product

Oil coke Refinery gas

[Gas]Flammable natural gas Imported natural gas (LNG) Domestic natural gasCity gas City gas [Electric power]Generation side Heat supplied to power generatorConsumption side Heat produced from electric power

[Heat]Consumption side Heat produced from steam

Temporary value

old NGL

old Other oil product

old LNGold Natural gas

Efficiency 39.98%

100oC, 1 atmSaturated steam

97.0kcal/mol29.4kcal/mol

38.2kcal/mol

31.4kcal/mol18.2kcal/mol10.0kcal/mol

17.9kcal/mol49.3kcal/mol

(1)

(2)(3)

(4)

(5)(6)(7)

(8)(9)

12

Unification with CO2 separation �and fixation technology



>65% sending end efficiency

Muza Kawasaki Central Tower 16F, 1310, Omiya-cho, Saiwai-ku, Kawasaki-shi, Kanagawa 212-8554

TEL.044-520-5290 FAX.044-520-5292

URL: http://www.nedo.go.jp/

Sumitomogaien Bldg 7F, 24, Daikyocho, Shinjuku-ku, Tokyo 160-0015

TEL.03-3359-2251 FAX.03-3359-2280

URL: http://www.ccuj.or.jp/

�New Energy and Industrial Technology Development Organization

Center for Coal Utilization, Japan

Coal Fired Power �Generation �Technology

Iron Making and �General Industry �

Technology

Multi-Purpose �Coal Utilization �

Technology��

Basic Technology �for Advanced Coal �

Utilization

Co-production �System

Environmental �Load Reduction �

Technology��

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