Development of High Efficiency CFB Technology to Provide Flexible Air/Oxy Operation for Power Plant with CCS

FLEXI BURN CFB

2nd International Workshop on Oxyfuel FBC Technology Antti Tourunen

VTT Technical Research Centre of Finland

2

Aim : to develop and demonstrate FLEXI BURN CFB concept enabling to reach the target of near zero emission power plantsThe FLEXI BURN CFB concept:High efficiency Circulating Fluidized Bed (CFB) power plant with CCS capable of air/oxyoperation with a wide range of fuels including biomass

Project objective

The FLEXI BURN CFB concept has a set of important advantages:

1. fuel flexibility in order to decrease dependency on imported coals and in order to improve power plant economics especially with CCS operation

2. operational flexibility in order to apply air-firing and oxygen-firing with CO2 capture

3. lower NOx production due to reduced and more uniform furnace temperature profiles, and lower SOx concentration in flue gases due to in-furnace capture, thus reducing the need for downstream flue gas cleaning

4. overall concept for phased transition into CCS technology with minimised risks through high efficiency air-oxy flexible CFB combustion

5. lower specific CO2 emissions from the reduced consumption of fuel due to the intrinsic high efficiency of the technology . In addition, by substituting e.g. 20% of coal input with renewable fuels, CO2 emissions can further be reduced by 15-20%.

6. Provides utilities an attractive alternative to take into use the new technology and decommission old capacity with lower efficiency and poorer emission performance

3

FLEXI BURN CFB diagram allowing operation under normal air-firing as well as oxygen-firing with CCS

Large scale high efficiency CFB boiler with

FLEXI BURN design

FuelBituminous coalLigniteBiomassPet coke etc.

Air Separation Unit (ASU) Mixing

AirSwitch

Fluegas (CO2-rich)

Flue gas recirculation

SwitchStack

95-97% O2

Flue gas cleaning

CO2 capture and storage (CCS)CondensationCompressionPurificationTransportStorage

The FLEXI BURN CFB concept: High efficiency Circulating Fluidized Bed (CFB) power plant with CCS capable of air/oxy operation with a wide range of fuels including biomass

Role of FLEXI BURN CFB Partners

Research institutes

Utilities

Dev

elop

men

t ste

ps

Industrial applicability

VTT, LUT, CzUT UNIZAR-LITEC, AICIA

Endesa, EDP, Tauron Generation

Laboratory and small pilot scale test(0.1-1MWth)

Concept

1st Commercial scale FLEXI BURN CFB Power Plant

FLEXI BURN CFB project2009 - 2012

ManufacturersFWEOY, FWESA, ADEX, Siemens, Praxair

UAP

DemonstrationPilot Plant

30 MWth, CIUDEN

Demonstration of FLEXI BURN CFBCIUDEN 30MW th- air-/ oxy-firing with fuel flexibility- CO2 separation

Field measurements at OTU CFBLagisza 460 MWe - scale-up information from the world first and largest OTU CFB- design model validation

Commercial scale FLEXI BURN CFB Technology

Scale up criteria

FLEXI BURN CFB - General project structure

R&D support Design tools Demonstration Boiler design Power plant concept

Commercial Scale

FLEXIBURN

WP1 WP2 WP3 WP4 WP5 WP6

nc Xkm

tmr O2c

c

dd

COefCO Ykt

Yd

d

)/1/(1 mCOef kk

nrefv ddTAb )/)(/exp(

Modelanalyses

CO combustionMixingChar combustion

Volatile, m

oisture release

k W /m 2

1D-MO DELflue gas

1

n n+ 1

to stack

Pr ima ry airSeco nda ry air

2

n-1

3

n-2

BENCH SCALE REACTOR (BFB/CFB)

Air

O2, C O2, CO, N 2, SO2, NO

S econdary a ir

Continuousfue l feed

Fuel batch feed

Cooler/heater

Cooler

Primary gas heatingPC control and data logg ing sys tem

Cyclone

FilterTo Stack

BENCH SCALE REACTOR (BFB/CFB)

Air

O2, C O2, CO, N 2, SO2, NO

S econdary a ir

Continuousfue l feed

Fuel batch feed

Cooler/heater

Cooler

Primary gas heatingPC control and data logg ing sys tem

Cyclone

FilterTo Stack

Air

O2, C O2, CO, N 2, SO2, NO

S econdary a ir

Continuousfue l feed

Fuel batch feed

Cooler/heater

Cooler

Primary gas heatingPC control and data logg ing sys tem

Cyclone

FilterTo Stack

AGISZA 460 MWe supercritical OTU CFB

kW/m2

Bench scale Pilot scale Boiler scale

EXPERIMENTAL SCALES

MODELS FOR PHENOMENA 1-D PROCESS MODELS 3-D PROCESS MODELS

MODELS AND DESIGN TOOLS

M

Secondarycyclone

Fuel containers 1 and 2 Zone 1

Zone 2

Primarycyclone

Observation port

Deposit probe port

Zone 3

Zone 4

To stack

Sampling port

Sampling port

Sampling port

Additivecontainer

Air

Secondary gas

Primary gas heating

O2, CO2, N2

PC control and data logging system

Sampling port

Sampling port

Gas analysator

FTIR sampling port

FTIR sampling port

Sampling port

Sampling port

Gas coolingBag filterFlue gasrecirculation

M

Secondarycyclone

Fuel containers 1 and 2 Zone 1

Zone 2

Primarycyclone

Observation port

Deposit probe port

Zone 3

Zone 4

To stack

Sampling port

Sampling port

Sampling port

Additivecontainer

Air

Secondary gas

Primary gas heating

O2, CO2, N2

PC control and data logging systemPC control and data logging system

Sampling port

Sampling port

Gas analysator

FTIR sampling port

FTIR sampling port

Sampling port

Sampling port

Gas coolingBag filterFlue gasrecirculation

PILOT SCALE CFB COMBUSTOR

M

Secondarycyclone

Fuel containers 1 and 2 Zone 1

Zone 2

Primarycyclone

Observation port

Deposit probe port

Zone 3

Zone 4

To stack

Sampling port

Sampling port

Sampling port

Additivecontainer

Air

Secondary gas

Primary gas heating

O2, CO2, N2

PC control and data logging system

Sampling port

Sampling port

Gas analysator

FTIR sampling port

FTIR sampling port

Sampling port

Sampling port

Gas coolingBag filterFlue gasrecirculation

M

Secondarycyclone

Fuel containers 1 and 2 Zone 1

Zone 2

Primarycyclone

Observation port

Deposit probe port

Zone 3

Zone 4

To stack

Sampling port

Sampling port

Sampling port

Additivecontainer

Air

Secondary gas

Primary gas heating

O2, CO2, N2

PC control and data logging systemPC control and data logging system

Sampling port

Sampling port

Gas analysator

FTIR sampling port

FTIR sampling port

Sampling port

Sampling port

Gas coolingBag filterFlue gasrecirculation

PILOT SCALE CFB COMBUSTOR

Development and demonstration in multiple scales

Process scale-up

• CFB technology is scaling up with the latest high-efficiency SC-OTU-references Lagisza (460 MWe). The Lagisza power plant (460 MWe), located in the southern Poland, is the world's largest CFB boiler, which is also the world's first supercritical CFB once-through unit (OTU)

CFB800 agisza Turow 4-6 JEA Turow 1-3 Furnace - Width m 40 27.6 22.0 26.0 21.2 - Depth m 12 10.6 10.1 6.7 9.9 - Height m 50.0 48.0 42.0 35.1 43.5

Unit Capacity (MWe)

0

100

200

300

400

500

600

1970 1975 1980 1985 1990 1995 2000 2005 2010Start-Up Year

Pilot Plant Oriental Chem

Lagisza

JEA

Turow 1

VaskiluodonNova ScotiaTri-State

General Motors

800 800 MWeUnit Capacity (MWe)

0

100

200

300

400

500

600

1970 1975 1980 1985 1990 1995 2000 2005 2010Start-Up Year

Pilot Plant Oriental Chem

Lagisza

JEA

Turow 1

VaskiluodonNova ScotiaTri-State

General Motors

800 800 MWe

Reference plant for the project

OTU SC CFB Boiler layout at

Tauron GenerationLagisza Power

Plant

200 250 300 350 400 450 500

50

100

150

200

250

300

350

400

SO2 measuring data

Con

cent

ratio

n of

SO

2 [m

g/m

3 n](a

t O2 =

6%

in d

ry fl

ue g

ases

)

Unit load [MWe]200 250 300 350 400 450 500

50

100

150

200

250

300

350

400

NOx measuring data

Con

cent

ratio

n of

NO

x [mg/

m3 n]

(at O

2 = 6

% in

dry

flue

gas

es)

Unit load [MWe]

200 250 300 350 400 450 500

25

50

75

100

125

150

175

200

CO measuring data

Con

cent

ratio

n of

CO

[mg/

m3 n]

(at O

2 = 6

% in

dry

flue

gas

es)

Unit load [MWe]200 250 300 350 400 450 500 550

0

20

40

60

80

100

120

140

160

180

200

Dust measuring data

Con

cent

ratio

n of

dus

t [m

g/m

2 n](a

t O2 =

6%

in d

ry fl

ue g

ases

)

Unit load [MWe]

EMISSION ( at 6% O2, dry flue gas)(follows EU’s LCP directive), mg/Nm3

SO2 200

NOx (as NO2) 200

CO 200

Dust 30

Validation runs at a 460 MWe SC-OTU CFB boiler

750

775

800

825

850

875

900

925

950

0 5 10 15 20 25 30 35 40 45 50

Tem

pera

ture

[°C

]

Height [m]

Measured

calculated by model

Typical measurements during the test runs :Temperature profilesPressure profilesGas profilesProcess data (including emission data)Fuel and ash samples

BEN CH SCALE REACTOR (BFB/CFB)

Air

O2, C O2, CO, N2 , SO2, NO

Secon dary air

Con tin uou sfu el fee d

Fuel ba tch fee d

Co oler/hea ter

C ooler

Prima ry g as hea tin gPC con trol and d ata lo gging system

Cyclone

FilterTo Sta ck

BEN CH SCALE REACTOR (BFB/CFB)

Air

O2, C O2, CO, N2 , SO2, NO

Secon dary air

Con tin uou sfu el fee d

Fuel ba tch fee d

Co oler/hea ter

C ooler

Prima ry g as hea tin gPC con trol and d ata lo gging system

Cyclone

FilterTo Sta ck

A ir

O2, C O2, CO, N2 , SO2, NO

Secon dary air

Con tin uou sfu el fee d

Fuel ba tch fee d

Co oler/hea ter

C ooler

Prima ry g as hea tin gPC con trol and d ata lo gging system

Cyclone

FilterTo Sta ck

M

Secondarycyclone

Fuel containers 1 and 2 Zone 1

Zone 2

Pr imarycyclone

Observation port

Deposit probe port

Zone 3

Zone 4

To stack

Sampling port

Sampling port

Sampling port

Additivecontainer

Air

Secondarygas

Primary gas heating

O2, CO2, N2

PC control and data logging system

Sampling por t

Sampling port

Gas analysator

FTIR sampling port

FTIR sampling port

Sampling port

Sampling port

Gas coolingBag fil terFlue gasrecirculation

M

Secondarycyclone

Fuel containers 1 and 2 Zone 1

Zone 2

Pr imarycyclone

Observation port

Deposit probe port

Zone 3

Zone 4

To stack

Sampling port

Sampling port

Sampling port

Additivecontainer

Air

Secondarygas

Primary gas heating

O2, CO2, N2

PC control and data logging systemPC control and data logging system

Sampling por t

Sampling port

Gas analysator

FTIR sampling port

FTIR sampling port

Sampling port

Sampling port

Gas coolingBag fil terFlue gasrecirculation

PILOT SCALE CFB COMBUSTOR

M

Secondarycyclone

Fuel containers 1 and 2 Zone 1

Zone 2

Pr imarycyclone

Observation port

Deposit probe port

Zone 3

Zone 4

To stack

Sampling port

Sampling port

Sampling port

Additivecontainer

Air

Secondarygas

Primary gas heating

O2, CO2, N2

PC control and data logging system

Sampling por t

Sampling port

Gas analysator

FTIR sampling port

FTIR sampling port

Sampling port

Sampling port

Gas coolingBag fil terFlue gasrecirculation

M

Secondarycyclone

Fuel containers 1 and 2 Zone 1

Zone 2

Pr imarycyclone

Observation port

Deposit probe port

Zone 3

Zone 4

To stack

Sampling port

Sampling port

Sampling port

Additivecontainer

Air

Secondarygas

Primary gas heating

O2, CO2, N2

PC control and data logging systemPC control and data logging system

Sampling por t

Sampling port

Gas analysator

FTIR sampling port

FTIR sampling port

Sampling port

Sampling port

Gas coolingBag fil terFlue gasrecirculation

PILOT SCALE CFB COMBUSTORVTT0.3kW

VTT0.1MW

CANMET1MW

CIUDEN30MW

Dem

onst

ratio

n sc

ales

Time

Concept for 300 MWe

2009 2012

FLEXI BURN CFB – Demonstration steps

Completed

In progress

Aim : to develop and demonstrate FLEXI BURN CFB concept enabling to reach the target of near zero emission power plants

Laboratory scale combustion tests have been carried out with pilot scale and bench scale test rigs at VTT

Tests provide a base for development and validation of the design tools needed in the concept development

Totally seven different fuels were selected for the combustion tests

The selected project fuels cover the whole range of coals from anthracite to lignite

Straw pellet represents a typical agrobiomass which is easily available whereas wood represents a typical good quality forest-based biomass which is also available in many locations of the Europe

Small pilot scale CFB experiments (0.1MW) under air- and oxygen-firing conditions

Fuels Mixture ratio on energy basis (LHV wet)

Mixture ratio on mass basis (wet)

Anthracite + Pet-coke 55/45 70/30Anthracite 100 100Bituminous coal (Polish) 100 100Lignite (Spanish) + South African coal 55/45 70/30Anthracite + wood 90/10 85/15Bituminous coal (Polish) + straw pellet 80/20 75/25

Small pilot scale CFB experiments (0.1MW) under air- and oxygen-firing conditions

Air-firing Oxygen-firing

Air-firingOxygen-firing

Fuel reactivity

Transition between air- and oxygen-firing

Combustion process dynamics

Ash characteristics: air/oxy

Air-firng (Test 19)

CaCO3 [%]CaO [%]CaSO4 [%]

Oxygen-firing (Test 20)

CaCO3 [%]CaO [%]CaSO4 [%]

Bottom ash

Bottom ash

Oxygen-firing test with high temperature

Air-firing testMeasured calcium compounds in bottom ash

Model based analysis of the CANMET test data

• Detailed analysis of solids mass balance

• Furnace vertical temperature profile

• Combustion and energy release profile

• Solids density profile

• Heat flux profile

Furnace heat transfer

500

550

600

650

700

750

800

850

900

950

1000

0 2 4 6

Tem

pera

ture

Furnace height

High load OXYHigh load AIR

– 15 test weeks

– Runs: 88 of which

– 35 in air combustion

– 53 in oxy combustion

Test program at CanmetENERGY, Ottawa

FLY ASHSILO

FLY ASHFEEDING SYSTEM

LIMESTONESILO

LIMESTONE,DeSOx

LIMESTONEFEEDING SYSTEM

SAND SILO

SAND FEEDINGSYSTEM

FUEL SILO

FUEL FEEDING SYSTEM

NATURALGAS

START-UP BURNER

SKID

BOILER FEED WATER

FLUE GAS

BOTTOM ASH

FLY ASHSYSTEM

PRIMARYOXIDANTFAN

SECUNDARYOXIDANTFAN

MIXER

FLY

ASH

REC

IRC

ULA

TIO

N

LIM

ESTO

NE

SAN

DFU

EL F

EED

AMMONIA,DeNOx

MIXER

MIXER

CB1

CB2

OXYGEN

CIRCULATING FLUIDIZED BED BOILER – FLOW DIAGRAM

Demonstration runs at a 30 MWth CFB pilot plant

Presentation on Thursday 28th June:Oxyfuel testing at 30MWth CIUDEN Oxy-CFB boiler

Plant size:

Specifications for a FLEXI BURN CFB demonstration plant

• Two cases considered:

Flexi Burn CFB demonstration plant: – 300-350 MWe gross. (Detailed technical scope, main focus)

Full Commercial plant - post-2020: – 800 MWe gross (techno-economical feasibility study)

Operating parameters: Dynamic requirements for the power plant

Operational Mode Base Load

Load change rate Max ramping 4%/min

Minimum load 40%

Start-up time (cold) <24h

Start-up time (ASU cold) <8h

Annual equivalent operating hours

Oxy mode 6500 h

Air mode 500 h

TOTAL 7000 h

600 ºCReheated steam temperature

57 barReheated steam pressure

270 barMain steam pressure

598 ºCMain steam temperature

600 ºCReheated steam temperature

57 barReheated steam pressure

270 barMain steam pressure

598 ºCMain steam temperature

Steam parameters:

CONCENTRATIONH2O < 500 ppmCO < 2000 ppm

O2 + N2 + Ar < 4 vol%SOx < 100 ppmNOx < 100 ppmCO2 >95.5 %

Specifications for a FLEXI BURN CFB demonstration plant

• Air inleakage: Base case 1% (sensitivity analysis up to 3%)

• O2/CO2 ratio: close to air concentration (24% O2 wet)

• Oxygen purity:

Oxygen purity 96,6 % volPressure 1,2 barTemperature 20 ºC

Other oxycombustion criteria:

CO2 compressed to transport by pipeline

Current status (1/2)A lot of experimental work has been carried out in order to support the development of FLEXI BURN CFB concept

Combustion tests in different scales and field measurements in a commercial scale power plant provide a base for development and validation of the design tools needed in the concept development

Large scale high efficiency CFB boiler with

FLEXI BURN design

FuelBituminous coalLigniteBiomassPet coke etc.

Air Separation Unit (ASU) Mixing

AirSwitch

Fluegas (CO2-rich)

Flue gas recirculation

SwitchStack

95-97% O2

Flue gas cleaning

CO2 capture and storage (CCS)CondensationCompressionPurificationTransportStorage

Demonstration tests at different scales:

– VTT 0.1MW, CANMET 1MW has been completed (totally over 100 oxyfuel test balances) with encouraging results

– Flexible operation under air- and oxygen-firing modes have been successful demonstrated in the small scales 0.1MW-1MW

– Validation test campaigns with the world first and the largest (460 MWe) OTSC-CFB has been successfully completed

Current status (2/2)

The design parameters for a FLEXI BURN CFB plant, from a technical and operational point of view, have been determined

Two cases considered: 1) Flexi Burn CFB demonstration plant: 300-350 MWe gross 2) Full Commercial plant - post-2020: 800 MWe gross

The conceptual design of the FLEXI BURN CFB boiler has been developed

The conceptual design for the FLEXI BURN has been implemented including a preliminary integration with the Air Separation Unit (ASU) and the Compression and Purification Unit (CPU)

Boiler

CPUASU

SteamCycle

Oxidant Flue gas

IntegrationIntegration

Power Utilities Power Utilities

Next steps• Demonstration tests at CIUDEN are ongoing

• Final verification of the concept based on the test results form CIUDEN

• Concept optimisation for the boiler island and the integrated power plant unit including dynamic simulation of the plant

• Health and safety assessment related to oxygen-firing conditions

• Estimate economics for the new concept and evaluate their feasibility on a commercial scale range

• Identification of the key success factors of the FLEXI BURN CFB technology covering the process efficiency, operability, maintainability, environmental impact and responsiveness to the market requirements, all leading to the economic performance of this new approach for power generation

• Project completed by February 2013

FLEXI BURN CFB

• More information on the project http://www.vtt.fi/sites/flexiburncfb/

Acknowledgements:The research leading to these results has received funding from the European

Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 239188.