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CO2 Capture with Foster Wheeler´s
Flexi-burnTM CFB Technology
Reijo Kuivalainen
Foster Wheeler Energia Oy
ClimBus programme seminar, June 9-10th, 2009
Contents of Presentation
• Background: CFB technology basis, CO2 reduction and CO2 capture and storage (CCS) options
• Oxy-fuel CFB combustion: principle, advantages and challenges
• Development of Flexi-burnTM CFB boiler
• Test results of pilot scale experiments
• Conclusions
67 %
18 %
9 % 4 % 2 %COALS
PET COKE
BIO
LIGNITE
OTHERS
Foster Wheeler is the market leader in Circulating Fluidized
Bed Technology
350 CIRCULATING FLUID BED (CFB) BOILERS
• Total 24 000 MWe CFB sold
• 309 in operation for variety fuels:
coal, lignite, petroleum coke, biomass,
RDF, etc.
• 32 under construction
• Biggest unit in operation 300 Mwe
• 465 Mwe OTU CFB started up
Tot. >24 GWe CFB
Foster Wheeler Fluidized Bed Technology Basis
Nearly 30 Years and 22 Gwe
Foster Wheeler Energia Oy in Finland is the Technology Center for Fluidized Bed Boilers in Foster
Wheeler Global Power Group
Foster Wheeler Develops CFB Technology to
Meet Future Challenges of Power Generation
• scaling up the CFB technology
• increasing efficiency
• improving environmental performance
• widening the fuel flexibility
• adapting CFB for CCS
BackgroundMainstream CCS Technology Options with Fossil Fuels
• Short and medium term approach to CO2
reduction:
• Increase of efficiency
• Co-firing of coal with fuels considered CO2
neutral
• Main technology options for CO2 capture in power production
• Post-combustion capture
• Pre-combustion capture
• Oxy-fuel combustion
BackgroundImpact of Efficiency and Improvement and biomass co-firing on CO2 Reduction
100% coal
Thermie Ultimo
Thermie SR
Average Europe
CFB today
10% biomass
20% biomass
400
500
600
700
800
900
1000
1100
1200
25 30 35 40 45 50 55 60
Net efficiency (lhv, %)
2 CO emission (g/kWh)
% biomass on LHV
21%
34%
BackgroundCCS Technology Development at Foster Wheeler
• GHG emission trading systems and/or emission caps are expected to lead into demand for solutions to near zero emission power (and heat) production of fossil fuels
• CCS-ready new plants – retrofits – greenfield plants with CCS
• Of the main technology options, FW is mainly focusing on Oxy-fuel combustion in CFB boilers
• The Oxy-fuel CFB development is carried out in Finland
• Development carried out in parallel as
• Internal development (modeling/design tools, boiler engineering, economics,...)
• Partnership in R&D with research institutes and universities (pilot testing, modelling, etc.)
• Participation in public R&D
• Demonstrations
Oxy-Fuel Combustion Process
Steam
turbine
Flue gas
recycle
BoilerCompression
Purification
Flue gas
cleaning
CO2
Air Air separation N2, (Ar)
G
Coal
CO2/H2O
H2O
Condensation
Transport
Storage
Vent gas95-99+% O2,
(Ar, N2)
Oxy-Fuel CFB TechnologyMain Advantages
• The established CFB advantages exist also in CFB
oxycombustion: low furnace temperatures, hot
circulating solids, long solid residence time
• Multi-fuel capability (coal, petroleum coke, lignites,
biomasses), simple feed systems – capability to utilize
cheap fuels emphasized due to CCS efficiency penalties
• SOx and NOx reduction without scrubbers
• Good fuel burnout and sorbent utilization
• Efficient heat transfer and uniform heat flux
• Enables Flexi-burnTM CFB boiler design: the same boiler
can be operated in air firing or oxy firing mode with CCS
• Further potential: high O2 contents (> 30 – 35 %)
Flexi-BurnTM CFB
Large scale
high efficiency
CFB boiler with
FLEXI BURN
designFuel
Bituminous coal
Lignite
Biomass
Pet coke etc.
ASU Mixing
Air
O2
Switch
Fluegas
(CO2-rich)
Flue gas recirculation
Switch
To stack
CCS
CO2 capture
and storage
Large scale
high efficiency
CFB boiler with
FLEXI BURN
designFuel
Bituminous coal
Lignite
Biomass
Pet coke etc.
Fuel
Bituminous coal
Lignite
Biomass
Pet coke etc.
ASU Mixing
Air
O2
Switch
Fluegas
(CO2-rich)
Flue gas recirculation
Switch
To stack
CCS
CO2 capture
and storage
• Oxy-ready design for
subsequent
implementation of CCS
• In greenfield installations
with CCS, the concept
serves risk mitigation
intrests by enabling power
production e.g. in case of
unavailability of storage
facilities.
Oxy-CFB TechnologyChallenges for developing CFB for Oxy-fuel
At moderate O2 concentrations:
• Combustion behaviour
• Heat transfer
• Materials (corrosion, deposits)
• Prediction of emissions
• Controls
• Gas properties change
• (, cp, etc.)
• Hydrodynamics
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
/to
tal h
ea
t d
uty
[%
] 0
10
20
30
40
50
60
70
80
90
100
O2
sh
are
if inp
ut g
as
[%]
Existing CFB units / designs
O2 CFB designs
O2 share of input gas (O2/CO2)
normal air
combustion
At high O2 concentrations additionally:
• Adiabatic combustion temperature rises.
• The generated heat per volume is substantially higher.
• Flexi-burn firing more challenging (air and oxy in the same boiler)
Oxy-Fuel TechnologiesEfficiency Penalty
• Maximizing gross efficiency to minimize
penalty
• Reduction of oxygen production costs
• High internal power consumption
Cooling
1084MW
(53.5%)
Efficiency
(net),
%
05
1015202530354045
Refe
ren
ce
pla
nt
O2/C
O2
pla
nt
Fuel input
2026MW
100%
Original
electricity
output 865MW
(42.7%)
CO2 compression
71 MW – 3.5%
Air separation
137 MW – 6.8%
Auxiliaries
45 MW – 2.2%
Air separation and CO2 compression
requires massive amounts of energy......resulting in 8-12 %-
points lower efficiency
689MW
output –
34%
Source: Chalmers / Andersson
• System-level integration
• Space requirements
80 m
Flue gas
recycle
Oxygen
Flue gas
condenser
100 m
Oxy-Fuel TechnologiesRequires large space for ASU and CPU
Development of Flexi-BurnTM CFBMain Activities
• Foster Wheeler has been developing oxy-fuel CFB combustion since 2003:
• Knowledge and design tool development
• Test activities (VTT bench scale & small pilot CFB)
• Conceptual and feasibility studies (boiler design)
• In parallel, scale-up of air-fired CFB boilers has continued. FW is starting up the world largest and first SC-OTU CFB at PKE’s Lagisza plant in Poland and develops CFB technology further up to 600-800 MWe size with 600 °C steam temperature.
• The Spanish government has decided on investment for the CIUDEN 30 MWth
class pilot CFB facility, which provides a full experimental CCS platform for the demonstration and validation of oxy/air-fuel combustion in sufficient scale to allow continuation to commercial scale.
• FW has provided basic engineering of the CFB and PC boilers and negotiates for the supply contract of the boilers.
• Experiences in scale-up of CFB boilers up to 460 MWe size and on the other hand in planned air / oxy firing demonstration in 30 MWth size will be combined.
Develop the Flexi-burn CFB boiler concept and demonstrate the technology.
• Endesa Generación plans to demonstrate a 500 MWe scale Flexi-burn CFB for CCS within EU’s flagship CCS demonstration program.
• FW together with Praxair will provide the technology for the CFB boiler and carbon capture.
• Feasibility studies with other utilities
• FWNA is cooperating with Praxair in the development of 50 MWe Oxy-CFB demonstration at Jamestown plant in New York state.
Development of Flexi-BurnTM CFBMain Activities
Development of Flexi-BurnTM CFBScale-up Path
Demonstration of Flexi-burn CFB15 – 30MWth
• Air-/ oxyfiring with fuel flexibility
• CO2 separation
Lagisza 460 MWe OTU CFB• Scale-up information from the world's largest CFB
• Experiences of the world's first SC OTU CFB
• Design model validation
Commercial scale
Flexi-burnTM CFB
technology in
>500 MWe size
Scale-up
criteria
Existing know-how• Supply of over 300 CFB boilers up to 300 MWe
• Long-term development of design tools
Oxy-CFB Testing and Development
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
ŁAGISZA 460 MWe supercritical OTU CFB
kW/m2
Bench scale Pilot scale Boiler scale
EXPERIMENTAL
SCALES
Models for
phenomena1-D Process
models3-D Process
models
MODELS AND
DESIGN
TOOLS
Oxy-CFB ExperimentsVTT Test Facilities
• Experimental oxy-fuel combustion studies
with small scale fluidized bed combustors at
VTT in Jyväskylä since 2004
• Pilot scale (30-100 kW) circulating fluidized
bed (CFB) reactor
- Combustion with O2 + recycled flue gas
- Combustion with bottled gases
- Air firing
• Bench scale BFB/CFB reactor (< 1 kW)
suitable for studies of oxygen combustion
phenomena
M
Secondary
cyclone
Fuel containers 1 and 2 Zone 1
Zone 2
Primary
cyc lone
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 por t
Sampling port
G as analysat or
FTIR sampling port
FTIR sampling port
Sampling port
Sampling port
Gas coolingBag filt erFlue gasrecirculation
M
Secondary
cyclone
Fuel containers 1 and 2 Zone 1
Zone 2
Primary
cyc lone
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 por t
Sampling port
G as analysat or
FTIR sampling port
FTIR sampling port
Sampling port
Sampling port
Gas coolingBag filt erFlue gasrecirculation
PILOT SCALE CFB COMBUSTOR
M
Secondary
cyclone
Fuel containers 1 and 2 Zone 1
Zone 2
Primary
cyc lone
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 por t
Sampling port
G as analysat or
FTIR sampling port
FTIR sampling port
Sampling port
Sampling port
Gas coolingBag filt erFlue gasrecirculation
M
Secondary
cyclone
Fuel containers 1 and 2 Zone 1
Zone 2
Primary
cyc lone
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 por t
Sampling port
G as analysat or
FTIR sampling port
FTIR sampling port
Sampling port
Sampling port
Gas coolingBag filt erFlue gasrecirculation
PILOT SCALE CFB COMBUSTOR
Oxy-CFB ExperimentsEmissions in Pilot Scale Tests
SO2 Emissions and Calcium
Utilization with Bituminous Coal
NO Emissions with Bituminous Coal
Heat Fluxes of the CFB Furnace are Favourable for Oxycombustion3D Modelling Results
Air combustion Oxy Combustion
50
40
35
30
25
20
15
10
5
0
45
0 100 200 300 400
Fu
rnac
e H
eig
ht
[m
]
Heat flux (average) [kW/m²]
PC furnace
CFB furnace
Comparison of heat fluxes in CFB and PC
Air Combustion
www.oxygenie.com
Flexi-BurnTM CFB Boiler DevelopmentSummary
• Development approach based on theoretical studies, experiments at different scales, compilation of the acquired know-how in design tools / process models used in designing boilers
• The Lagisza 460 MWe CFB boiler has been used as a reference in oxycombustioncase studies (retrofit & greenfield Flexi-burnTM CFB)
• Prediction tools show studied oxy-fuel boiler configurations viable.
• Experimental results from bench and pilot scale test units show good emission performance.
• Adapting an existing CFB boiler design for oxycombustion appears technically feasible without major changes in the boiler structures and heat surfaces.
• Uncertainties in prediction of large scale performance will be eliminated
Models are being modified and testing continued to consider oxycombustion characteristics
Demonstration in 15 – 30 MW scale scheduled to start in 2010
Capability to offer Foster Wheeler Flexi-burn design by 2011
www.oxygenie.com
Thank You!
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