September 8 - 9, 2013 Ponferrada Spain 5th Oxyfuel Capacity Building Course

DEVELOPMENT OF OXY-FUEL CFB

TECHNOLOGY FOR POWER GENERATION

Presented by

Timo Eriksson,

Foster Wheeler Energia Oy, Finland

Contents of Presentation

• Background

• Development of Oxy-Fuel CFB technology

• Course of development

• Modeling of oxy-fuel CFB combustion

• Pilot testing activities

• OXY-CFB-300 Compostilla boiler concept

• Summary

"Flexi-Burn" is a trademark of Foster Wheeler AG, registered in the U.S., EU, Finland

WORLD BOOK

Encyclopedia

Development of Oxy-Fuel CFB Technology Background

-200

-100

0

100

200

300

400

500

0 1000 2000 3000 4000 5000 6000 7000

NuclearFuel switch

to gas

CO2 capture

Solar

Geothermal

Efficiency

(end-use and

supply)

Average

Minimum

Maximum

US avoidance

potential

(millions of

tons of CO2)

Source: DOE white paper, 1997

• Avoidance cost:

DOE study from

1997 estimated

CO2 capture cost

at 50 $/ton of

CO2 avoided

• High potential in

avoided volumes

Avoidance cost

$ / t_CO2 (1990)

Development of Oxy-Fuel CFB Technology Roadmap for Development

Release of

oxycombustion

demonstration projects:-Vattenfall /

Schwarze Pumpe, 30 MWth

-Total / Lacq, 50 MWth

Feasibility studies

Process studies

Cost analyses

Market studies

Environm. impact studies

2000

General research & development work

2003 2006 2009 2012 2015

Techno-economic studies

EU/USA 2nd phase demos

EU/USA MW-size demos

Power plant

scale

demonstration

Commercial

size power

plant

Combustion

Emissions

Hydrodynamics

Materials

Technology development

Commissioning

of Oxy-pilots

• Progress in

technology

development

more or less in

schedule

• Large pilots

successful

• But step to large

demos turned out

to be a major

leap • Permitting

• Acceptance

• Economics

Phase II: Construction & operation

2008 2009 2011 2014 2010 2012 2013 2015 2016 2020

VTT

CANMET

CIUDEN

PILOT TESTING

BOILER CONCEPT DEVELOPMENT

SUPPORTING R&D

Development and validation of static and dynamic models

Material studies and testing

FP7 FLEXI BURN CFB

TEKES PROJECTS

FP7 O2GEN

OXY-CFB-300 Compostilla Phase I FID

Commercial cases

Flexi-Burn CFB

OXY-CFB-300

HIGH-O2 CFB

Development of Oxy-Fuel CFB Technology Development Timeline of Flexi-Burn CFB

Development of Oxy-Fuel CFB Technology Challenges

Oxy-CFB in general (1st & 2nd gen.): • Materials in the high CO2 and H2O gas

atmosphere

• Elimination of air in-leakage

• Limestone behavior

• Emissions prediction

• Changes in hydrodynamics and heat

transfer

• Process integration

High-O2 designs (2nd gen.): • Generated heat per volume [kW/m3] and

adiabatic combustion temperature rise.

• Heat balance between hot loop and

HRA area changes

• Heat surface configuration

28

40

60

80

100

0

10

20

30

40

50

60

70

80

90

100

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000

T adiabatic [°C]

ho

t lo

op

sh

are

of

tota

l h

eat

du

ty o

f b

oil

er

[%]

0

10

20

30

40

50

60

70

80

90

100

O2 s

hare

if inp

ut g

as [%

]

Existing CFB units / designs

O2 CFB designs

O2 share of input gas (O2/CO2)

normal air

combustion

Flexi-Burn CFB

Needs for • Experiments in bench scale and pilot test facilities

• Development and validation of design models

• Long-term demonstration runs

Development of Oxy-Fuel CFB Technology Integrated Experimental and Modeling Work for Scale-Up

nc Xkm

t

mr O2c

c

d

d

COefCO Ykt

Y

d

d

)/1/(1 mCOef kk

nrefv ddTAb )/)(/exp(

Model

analyses

CO combustion

Mixing

Char combustion

Volatile,

moist

ure re

lease

Figure 2 Furnace heat flux

kW/m

2

1D-MODELflue gas

1

n n+1

to stack

Primary airSecondary air

2

n-1

3

n-2

kW/m2

Sub-models

for phenomena 0-D and 1-D stationary /

dynamic models

1-D design model

3-D CFB model

EXPERIMENTAL

SCALES

MODELS AND

DESIGN TOOLS

Boiler scale Pilot scale (small>large) Bench scale

LAGISZA 460 MWe supercritical OTU CFB VTT 0.1 MW CFB pilot test rig VTT 0.3 kW CFB/BFB bench scale test rig

Development of Oxy-Fuel CFB Technology Main Activities

In CCS, Foster Wheeler is mainly focusing on oxy-fuel combustion, having been

developing it since 2003:

• Knowledge and design tool development

• Test activities starting from bench scale

• Conceptual, feasibility and FEED studies (boiler design)

Pilot test activities at larger scale facilities

• ~0.1 MWt (VTT) → ~1 MWt (Canmet 2009-2010) → 30 MWt (2011-13)

• FW supplied the 30-MWt CFB boiler at the CIUDEN technology development plant.

Experiences in scale-up of CFB boilers up to 460 MWe size and on the other hand

in air / oxy firing demonstration in pilots have been combined Flexi-Burn CFB

boiler concept developed and ready for demonstration.

CFB Boiler Development

In parallel, scale-up of air-fired CFB boilers has continued.

• The world first SC-OTU CFB at PKE’s Lagisza plant in Poland started commercial

operation in 2009.

• FW is supplying 4 x 550 MWe CFB boilers for Samcheok Green Power Project in Korea

(KOSPO), with 258/54 bara, 603/603 °C steam parameters.

• Developed CFB technology further up to 600-800 MWe (for ~ 45 % net efficiency) unit

size

Development of Oxy-Fuel CFB Technology Recent Activities

R&D support - EU FP7 project "FLEXI BURN CFB"

2009 – 2013 • Design tool development toward oxy & air compatibility

(combustion, heat transfer, fluid dynamics, emissions)

• Experiments in small and large scale pilots → scale-up

information

• Performance of materials

• Dynamic simulations

• Concept optimization, etc.

Boiler design - Oxy-CFB-300 Compostilla project 2009

– 2013 • Engineering of Flexi-Burn CFB boiler

• Performance and cost estimates

• Design verification at CIUDEN TDP

• Support of FEED study by ENDESA → plant level estimates

Development of Oxy-Fuel CFB Technology Model Development for Oxycombustion

Long-term activity, extended to implement also oxycombustion phenomena and

achieve full oxy-applicability • Development work in cooperation with partners, especially LUT (Lappeenranta University of

Technology) and VTT (Technical Research Centre of Finland)

• Several R&D projects, such as FLEXI BURN CFB (FP7 project)

• Sub-models for combustion, emission performance, heat transfer

• In-house CFB boiler design software combined with 1D CFB furnace and hot loop model and

emission models

• 3D model that simulates the furnace process

• Dynamic modeling (Simulink, Apros)

• Integrated process modeling for ASU - boiler - turbine - CPU

Interaction between modeling and measurements • Sub-models bench scale

• 0D and 1D static and dynamic models pilot scale

• Large pilot scale applicable also for 3D profile measurements and validation

• 1D and 3D design of commercial plants & field measurements

• In air firing furnace profile measurements done at Lagisza (furnace 28 x 11 x 48 m)

• In oxycombustion furnace profile measurements done at CIUDEN in oxy & air modes

• Combining the knowledge has enabled prediction of large oxy-CFB furnace performance

Development of Oxy-Fuel CFB Technology 1D Model Development

• 1D CFB furnace model is one of the core

modules in the FWOY´s boiler design

software.

• 1D furnace model is comprised of several

sub-routines simulating process

phenomena in combustion and CFB hot

loop (including INTREX).

• Emission models

• Oxycombustion features have been

implemented in the model (e.g.oxidant

system)

CFB boiler design

software

• Validation of the 1D CFB furnace model with test data • Measured furnace temperature, pressure (solids density) and oxygen profiles

• Feed material & ash flow rates, chemical composition, physical properties and PSD ash

balance (also fractional balances for different particle sizes)

• Circulating solids: composition, PSD

Development of Oxy-Fuel CFB Technology 3D Model Development

• 3D model simulates the furnace process. • Furnace divided to control volumes

• Boundary conditions include all the different feeds (e.g. fuels, gas feeds) and thermal conditions at walls.

• Separate models for separators and INTREX units

• Developed submodels (e.g. sorbent model) implemented to the 3D model

• Improvements to increase the robustness of the code and the calculation speed

Separator(s)

- separation eff.

- heat transfer

- reactions

Heat transfer

to walls and

internal

surfaces

Fluidization gas

Inlet sources

- sec. gas

- fuel

- limestone

- sand

External heat

exchangers

- heat transfer

- reactions

Flue gas,

fly ash

Exchange of

gas / solids

Solids to

furnace

Gas, solids

Combustion,

gasification &

other reactions

Solids

Bottom ash

Fluidization

gas

Recirculation of flue gas / fly ash

Solids

Gas

• Applied e.g. for studying the number and placement of fuel and oxidant feeds, in-furnace heat exchangers and separators temperature, velocity and gas composition profiles, heat fluxes

Development of Oxy-Fuel CFB Technology Dynamic Model Development

• Dynamic model / module development for FLEXI BURN CFB boiler system,

building on existing air-fired models validated for large CFB units (e.g. Lagisza

460 MWe SC-OUT CFB)

• Sub-models: furnace, water/steam path, flue gas path, combustion gas

preparation (mixing recirculated flue gas and oxygen)

• The model excludes the ASU, CPU and the BOP (balance of plant) systems;

integrated plant modeled separately (VTT).

• The model is capable to perform between 40% and 100% BMCR.

• The main control loops, unit master control, boiler control and steam temperature

control loops are applied.

• The 1-D dynamic hot-loop model (Simulink) is integrated into the Apros boiler

simulation model as dll module.

• Both steady-state and dynamic performances of the 300 MWe Flexi-Burn CFB

boiler have been investigated in Apros simulation environment.

Development of Oxy-Fuel CFB Technology VTT Tests

Experimental oxy-fuel combustion studies with

small scale fluidized bed combustors at VTT in

Jyväskylä since 2004

Small pilot scale (30-100 kW) circulating

fluidized bed (CFB) reactor • Height of riser 8 m, ID 0.17 m

• Combustion with O2 + recycled flue gas

• Combustion with bottled gases

• Air firing

• Several fuels tested, e.g. S.A. and Polish bituminous coals, Spanish and Russian anthracites, petcoke

• Steady-state and dynamic tests

Bench scale BFB/CFB reactor (< 1 kW) suitable

for studies of oxygen combustion phenomena

Development of Oxy-Fuel CFB Technology VTT Tests: Bottom Ash Characteristics

Air-firng (Test 19)

CaCO3 [%]

CaO [%]

CaSO4 [%]

Oxygen-firing (Test 20)

CaCO3 [%]

CaO [%]

CaSO4 [%]

Air firing test, Tb 845 °C

Oxycombustion test Tb 833 °C

A

A

Anthracite A

Bitum. coal

Anth./petc. A

A

A./p.

Oxycombustion test Tb 901 °C

Flexi-Burn CFB Boiler Development CANMET Tests

Design parameters: • Furnace: Ø 16” x 21.6 ft

• Refractory lined furnace, cyclone and return loop

• Four bayonet cooling tubes for furnace temperature control (adjustable on-line)

• Fuel and limestone feeding systems

• Recycle gas cooler ( dry RFG), fan and oxygen mixer for oxidant preparation

• Oxygen storage tank with a vaporizer and instrumentation

• Analyzers for continuous measurement of CO2, CO, O2, SO2, and NOx

• Data acquisition system

• Tests run with Spanish anthracite and lignite,

petcoke, S.A. bituminous coal and blends in

2010 • Totally 15 test weeks, 88 tests (35 air + 53 oxy)

• Focus on differences in combustion, emissions etc. between oxy and air combustion

Flexi-Burn CFB Boiler Development CANMET Tests

• Combustion, firing rate,

emissions-related issues,

mixing, heat transfer, fouling

and corrosion studied

• Steady combustion process in

both air and oxy modes

• The most important conclusion

was that no major issues

contradicting previous

assumptions and

understanding were identified

during the tests.

• Commissioning tests fall 2011 – spring 2012

• FLEXI BURN CFB (FP7) tests in July – September 2012

• EEPR tests (CPU integration) October – December

2012

• Altogether > 2000 hours of oxycombustion tests with

anthracite, petcoke, sub-bituminous and bituminous

coals, wood pellets or various blends

• So far all in so-called 1st generation oxy-CFB (Flexi-

Burn) • < 30 % O2 in oxidants

• Max. fuel input 18 MW

• Tests in so-called 2nd generation oxy-CFB mode with

higher oxidant O2 planned for 2013 - 2014

Flexi-Burn CFB Boiler Development CIUDEN TDP Tests

• Boiler operation and performance generally not outstandingly different (oxy vs. air)

• Furnace control with oxidant O2 demonstrated; similar oxidants used as in

planned OXY-CFB-300 boiler concept

• Optimal furnace operating parameters (e.g. temp.) with the design fuel determined

• Combustion efficiency similar in both modes

• Sulfur capture in oxycombustion proved very efficient at high temperatures but

poorer at temperatures below calcination (anthracite/petcoke).

• Existing design tools found valid for prediction of suspension density and heat

transfer in oxy mode

• No clear recarbonization issues encountered, however INTREX conditions not

fully representative (low solids outlet T)

• Correct PSD (crushing) of anthracite is important due to hard ash.

• No fouling in the HRA, sootblowing effective

• Acid dew point issues avoidable through limestone feeding, control of surface

temperatures and elimination of leaks (important also for flue gas CO2). Test

duration was obviously too short to experience boiler tube degradation.

OXY-CFB-300 boiler design verification

Flexi-Burn CFB Boiler Development CIUDEN TDP Tests: Significant Results

OXY-CFB Boiler Design Scale-Up from Pilot to Commercial Size

Parameter Unit CIUDENOXY-CFB-300

Flexi-Burn

CFB

Lagisza

460 MWe, gr.

700-MWe

High-O2 CFB

Furnace dimensions

Height m 20 37 48 52

Width m 2.9 28 27.6 29.7

Depth m 1.7 7 10.6 9.5

Number of separators - 1 4 8 6

Thermal power(1

Oxy mode (max.) MW 30 708 -- 1497

Air mode MW 14.5 647 966 --

Steam parameters(2

SH steam flow t/h 47.5 845 1300 1919

SH steam temperature °C 250(3

600 560 600

SH steam pressure bar 30 279 275 257

RH steam flow t/h -- 745 1101 1591

RH steam temperature °C -- 601 580 610

RH steam pressure bar -- 56.5 50.3 55

Feedwater temperature °C 170 290 290 300

Notes: 1) At CIUDEN fuel input; in others heat to steam

2) Steam parameters in Lagisza at turbine inlet

3) After spraying

OXY-CFB-300 Boiler Design Block Flow Diagram (80 % MCR Oxy/Air)

Boiler

Baghouse

INTREX

SH4

Wet flue gas recirculation

Oxygen preheater

HRS

Air

ASU

Fuel

Lime-

stone

Secondary oxidant

Primary oxidant (fluidizing gas)

Drying

Compression

Purification

CO2

Vent

gas

Transport

Storage

FGCC

SCAH 1Mixers

CPU

Turbine island

SCAH 2

Steam 2 Steam1

To cooling tower

1st stage2nd stage

HP EcoRH1 EcoSH3LP Eco

RH2

Air

Dry FGR

SH1

Ash

Flue gas properties

Oxy Air

CO2 %-mol 71.1 15.5

SO2 %-mol 0.03 0.01

O2 %-mol 3.10 3.33

N2 %-mol 4.51 74.5

Ar %-mol 2.75 0.89

H2O %-mol 18.5 5.77

M g/mol 38.0 30.2

Density kg/m3n 1.72 1.35

Oxygen properties

Oxy

O2 %-mol 96.6

N2 %-mol 0.10

Ar %-mol 3.30

Oxidant (primary) properties

Oxy Air

CO2 %-mol 54.8 0.03

SO2 %-mol 0.03 0.00

O2 %-mol 24.5 20.7

N2 %-mol 3.50 77.3

Ar %-mol 2.87 0.92

H2O %-mol 14.3 1.01

Parameter Unit Oxy mode Air mode

Fuel flow rate kg/s 25.2 25.3

Limestone flow rate kg/s 5.47 6.37

Oxygen flow rate (gross) kg/s 48.1 --

Air flow rate (gross) kg/s -- 235

Bed temperature °C 903 890

Furnace exit temperature °C 908 906

Filter inlet temperature °C 153 139

Flue gas outlet temperature °C 105 121

Flue gas flow rate, total kg/s 269 255

Recycled flue gas (wet) kg/s 183 --

Flue gas flow rate to CPU kg/s 86.5 --

OXY-CFB-300 Boiler Design Furnace Design

1

2

3

4

5

6

7

1. Furnace (evaporator walls, roof SH I, platen RH II at top)

2. INTREX (SH IV, 4 units)

3. Solids separator (SH I; 4 pcs)

4. Cross-over duct (SH II)

5. Heat recovery area, HRA (walls SH II; tube bundles RH

I, SH III, Economizer)

6. HP Eco and LP Eco

7. Flue gas to filter unit

• Low mass flux BENSON once-through technology

licensed by Siemens AG, Germany

• Furnace with gas tight membrane wall structure

• Heat surface setup shall fulfill the needs of SH and

RH steam in both operating modes, within the load

range.

OXY-CFB-300 Boiler Design Layout

PO mixer

SCAH

Filter

HRC

To CPU

Oxygen

SO

Fan house

Boiler house

Summary

• Foster Wheeler has been developing oxy-fuel CFB technologies for power

generation since 2004.

• Since 2007 the main focus has been in pursued large-scale demonstration in

Spain in cooperation with ENDESA and CIUDEN, in 2010 - 2013 supporting

the OXY-CFB-300 Compostilla project.

• The technology development approach has been similar to previous

development of CFB combustion up to utility size: static and dynamic

modeling, experimental work at different scales (pilot & field tests) and

engineering studies.

• Flexi-Burn CFB application has been succesfully demonstrated for carbon

capture in large pilot scale at the CIUDEN Technology Development Plant.

Experiences gained at the TDP have been used for validation of boiler design

tools and process models, and applied in the final boiler design. Flexi-Burn

CFB is technically ready for demonstration in integrated CCS process.

• Development of capture technology continues in high-oxygen CFB boiler

aiming for increased efficiency and lower cost.

www.oxygenie.com

Thank You!

The work leading to these results has been co-financed under the European Community’s Seventh Framework

Programme (FP7/2007-2013) under grant agreement n° 239188 and the EEPR09-CCS-COMPOSTILLA Project

(European Union's European Energy Programme for Recovery).