CETC

A Dual Fluid Bed Pilot Plant for Fuel Conversionand Co-firing Research

Fernando PretoBiomass & Renewables Group Leader

Advanced Combustion TechnologiesCANMET Energy Technology Centre – Ottawa

Natural Resources Canada

45th IEA FBC Meeting 18.11.2002

CETC

Fluidized Bed Combustion Pilot Plant ResearchCANMET Energy Technology CentreNatural Resources Canada

1980s Mark II AFBC unit 40 cm x 40 cm

1990s CFBC unit 40 cm ID (coal)

1995-> BFB unit (1 m ID)B: Bubbling & Biomass

Beyond-> Need for research beyond combustion

CETC

♦ Circulating Fluidized Bed Unit:0.8 MW thermal capacityrefractory lined, 0.4 m ID ~ 7 m highoperating temperatures up to 1000 C fluid. velocity to 8 m/sAutomated NG burnerDesigned for coal:

5 cm feed screw

Original CETC – CFBC Pilot Plant

CETC

♦ 1 MW Bubbling Fluidized Bed Unit:refractory lined,1 m ID - 6 m highoperating temperatures up to 1000 C fluidization velocity 1 – 3 m/sNG warm-up burner

Designed for biomass:25 cm overbed feed port15 cm underbed feed port

New BFB Pilot Plant

CETC Biomass Gasification Concept:- Wood Chips- Black Liquor

CETC

BFB

CFB

CFBCYCLONE

Riser 1

Riser 2

Star Valve

121 °CSaturated SteamFrom Main Boiler

Combustion Air

Cold Coke CycloneHot Coke Cyclone

12

14 16

08

24

2826

1004

18

2022

Pneumatic System

14 m high

CETC

Steam

“Cold” Circulation

Air“Hot” Circulation

A/burner

Baghouse

ID fanNCG

CETC-O Dual Fluid Bed Pilot Plant

Star Feeder

Stack

HXHX

Boiler

SH

LFF

L

Compressor

Compressor

Liq.

Solids Circulation: up to 6000 kg/h

CETC Dual Fluid Bed Pilot PlantBFB Transport CFB

CETC

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BFB

CFB

CFBCYCLONE

Riser 1

Riser 2

Star Valve

121 °CSaturated SteamFrom Main Boiler

Combustion Air

Cold Coke CycloneHot Coke Cyclone

12

14 16

08

24

2826

1004

18

2022

CETC

Temperature Changes for the Cold Coke Cyclone

-100

0

100

200

300

400

500

6:36:02 AM6:55:00 AM7:13:56 AM7:32:52 AM7:51:52 AM8:22:28 AM8:41:24 AM9:07:01 AM9:31:52 AM9:50:48 AM

10:09 :44 AM10:28 :40 AM10:47 :36 AM11:06 :32 AM11:25 :28 AM11:44 :24 AM12:03 :20 PM12:22 :16 PM12:41 :12 PM

1:00: 08 PM1:19: 04 PM1:38: 00 PM1:56: 56 PM2:15: 52 PM2:34: 48 PM2:53: 44 PM3:12: 40 PM3:31: 36 PM3:50: 32 PM4:09: 28 PM4:28: 24 PM4:47: 20 PM5:06: 16 PM5:25: 12 PM5:44: 08 PM6:03: 04 PM6:22: 00 PM6:40: 56 PM6:59: 52 PM7:18: 48 PM7:37: 44 PM7:56: 40 PM

Tim e

Tem

p (o

C) Inside

Outside

delta T

Transport – Monitor & Control Point

CETCDUAL FLUID BED HEAT BALANCE

Heat In = Heat Out + Heat Loss

Cp Heat Heat HeatkJ/kg/K kJ/kg kJ/Hour kW

HEAT SINKSMain Steam 75 500 526 2.166 56.3 4224 1.2

Atom Steam 6.7 350 526 2.166 381.2 2554 0.7 Heat RequiredPurge Steam 0 120 526 2.166 879.4 0 0.0N2 Purge 10 25 526 1.0416 521.8 5218 1.4Bitumen Feed 318 319.7 526 1.735 892.9 283946 78.9

Total Heat Req'd 2732 295943 82.2

HEAT SOURCE

Coke Circulation 5070.1 606 526 1.6 128 648973 180.3 Heat Input

Feed Rate (kg/min) 5.3Star Feeder (RPM) 14.64

Temp. In (oC)

Rate (kg/hour)

Temp. Out (oC)

CANMET 1M Reactor

HC Processing

Atom

Main

Purge N2

Hot Coke

Heat Loss

Cold Coke

Steam + N2

HC Feed

Product

CETCKey Temperatures

0

100

200

300

400

500

600

700

800

Time

Grn avg. temp. Red avg. temp. TPHRTI T 036

14:18>VTB feed

15:37> Tracer study

17:28> Iso 1

19:23>Iso 2

.

CETCReactor Bed Temperatures (Zoom)

470

490

510

530

550

570

590

14:0

0:12

14:1

1:40

14:2

3:08

14:3

4:36

14:4

6:04

14:5

7:32

15:0

9:00

15:2

0:28

15:3

1:56

15:4

3:24

15:5

4:52

16:0

6:20

16:1

7:48

16:2

9:16

16:4

0:44

16:5

2:12

17:0

3:40

17:1

5:08

17:2

6:36

17:3

8:04

17:4

9:32

18:0

1:00

Time

Tem

pera

ture

(Deg

. C)

TEW 220 TEW 222 TEW 224 TEW 225 T

14:18> VTB feed 15:37> Tracer StudyBed 6.5'-7'

17:28> Iso 1Bed ~7'

.

SS conditions:BFB temperature: ±±±± 2 °°°°CCirculation Rate: ±±±± 80 kg/hFluidization Steam: ±±±± 1 %Bed height: ±±±± 0.1 m

Dual Fluid Bed Operation

CETC

CETCCo-Firing Biomass & Fluid Coke

Preparing biomass for co-firing involves "tuning" the fuel mix and “verifying” boiler operation so that there is little or no loss in total efficiency. Since biomass in general has significantly less sulfur than coke, there is an SO2 benefit and there may also be NOx reduction, but this has to be evaluated.

Investment levels are very site specific and are affected by the available biomass, determining handling, size reduction and drying facilities, and the type of burner modifications.

CETC

Ash deposition and boiler tube corrosion can be an issue for some co-firing arrangements, depending on the biomass, ash chemistry, and operating conditions. Biomass can contain considerable alkali and alkaline-earth elements and chlorine, which, when mixed with other gas components derived from coke such as sulphur compounds, promotes a different array of vapour and fine particulate deposition.

CONCERN: CFBC combustion of fluid coke is typically above 900 C. This is a potential problem for biomass ash agglomeration

Ash Issues

CETC

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CETC

0

200

400

600

800

1000

1200

0 1 2 3 4 5 6Height, m

Tem

pera

ture

, C

CokeWoodCo-firing 50/50

CFBC – Temperature Profiles

CETC CFBC – Co-firing Flue Gas

Ash Analyses & further work continuing….

NA90NANOx

15028530SO2, ppm

380260150CO, ppm

4.35.64.6O2, %

5.24.05.4Vel. m/s

Mix:50/50CokeWood