CO2 Capture with Foster Wheeler s Flexi-burn TM CFB Technology Reijo Kuivalainen Foster Wheeler Energia Oy ClimBus programme seminar, June 9-10 th, 2009
Contents of Presentation Background: CFB technology basis, CO 2 reduction and CO 2 capture and storage (CCS) options Oxy-fuel CFB combustion: principle, advantages and challenges Development of Flexi-burn TM CFB boiler Test results of pilot scale experiments Conclusions
Foster Wheeler is the market leader in Circulating Fluidized Bed Technology 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 350 CIRCULATING FLUID BED (CFB) BOILERS Tot. >24 GWe CFB Total 24 000 MWe CFB sold 309 in operation for variety fuels: coal, lignite, petroleum coke, biomass, RDF, etc. 32 under construction 18 % 9 % 4 % 2 % 67 % COALS PET COKE BIO LIGNITE OTHERS Biggest unit in operation 300 Mwe 465 Mwe OTU CFB started up
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
Background Mainstream CCS Technology Options with Fossil Fuels Short and medium term approach to CO 2 reduction: Increase of efficiency Co-firing of coal with fuels considered CO 2 neutral Main technology options for CO 2 capture in power production Post-combustion capture Pre-combustion capture Oxy-fuel combustion
Background Impact of Efficiency and Improvement and biomass co-firing on CO 2 Reduction CO 2 emission (g/kwh) 1200 1100 100% coal 1000 10% biomass Average Europe 34% 21% 900 800 700 20% biomass CFB today Thermie SR 600 Thermie Ultimo 500 400 % biomass on LHV 25 30 35 40 45 50 55 60 Net efficiency (lhv, %)
Background CCS 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 Air Air separation N 2, (Ar) 95-99+% O 2, (Ar, N 2 ) Flue gas recycle Vent gas Coal Boiler Flue gas cleaning CO 2 /H 2 O Condensation Compression Purification CO 2 Steam turbine G H 2 O Transport Storage
Oxy-Fuel CFB Technology Main 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 SO x and NO x reduction without scrubbers Good fuel burnout and sorbent utilization Efficient heat transfer and uniform heat flux Enables Flexi-burn TM CFB boiler design: the same boiler can be operated in air firing or oxy firing mode with CCS Further potential: high O 2 contents (> 30 35 %)
Flexi-Burn TM CFB Oxy-ready design for subsequent implementation of CCS Fluegas (CO 2 -rich) Switch To stack In greenfield installations with CCS, the concept serves risk mitigation intrests by enabling power production e.g. in case of unavailability of storage facilities. Air Fuel Bituminous coal Lignite Biomass Pet coke etc. Switch Large scale high efficiency CFB boiler with FLEXI BURN design CCS CO 2 capture and storage ASU O 2 Mixing Flue gas recirculation
hot loop/total heat duty [%] Oxy-CFB Technology Challenges for developing CFB for Oxy-fuel At moderate O 2 concentrations: Combustion behaviour Heat transfer Materials (corrosion, deposits) Prediction of emissions Controls Gas properties change (, c p, etc.) Hydrodynamics 100 90 80 70 60 50 40 30 20 10 0 Existing CFB units / designs O2 CFB designs O2 share of input gas (O2/CO2) normal air combustion 28 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 T adiabatic [ C] At high O 2 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) 40 60 80 100 100 90 80 70 60 50 40 30 20 10 0 O2 share if input gas [%]
Reference plant O2/CO2 plant Oxy-Fuel Technologies Efficiency Penalty Maximizing gross efficiency to minimize penalty Reduction of oxygen production costs High internal power consumption Air separation and CO 2 compression requires massive amounts of energy... System-level integration Space requirements...resulting in 8-12 %- points lower efficiency Fuel input 2026MW 100% Original electricity output 865MW (42.7%) Air separation 137 MW 6.8% CO 2 compression 71 MW 3.5% 689MW output 34% Efficiency (net), % 45 40 35 30 25 20 15 10 5 0 Cooling 1084MW (53.5%) Source: Auxiliaries 45 MW 2.2% Chalmers / Andersson
Oxy-Fuel Technologies Requires large space for ASU and CPU Flue gas recycle Flue gas condenser 80 m Oxygen 100 m
Development of Flexi-Burn TM CFB Main 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 MW e size with 600 C steam temperature. The Spanish government has decided on investment for the CIUDEN 30 MW th 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.
Development of Flexi-Burn TM CFB Main Activities Experiences in scale-up of CFB boilers up to 460 MW e size and on the other hand in planned air / oxy firing demonstration in 30 MW th size will be combined. Develop the Flexi-burn CFB boiler concept and demonstrate the technology. Endesa Generación plans to demonstrate a 500 MW e 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 MW e demonstration at Jamestown plant in New York state. Oxy-CFB
Development of Flexi-Burn TM CFB Scale-up Path Existing know-how Supply of over 300 CFB boilers up to 300 MW e Long-term development of design tools Lagisza 460 MW e OTU CFB Scale-up information from the world's largest CFB Experiences of the world's first SC OTU CFB Design model validation Demonstration of Flexi-burn CFB 15 30MW th Air-/ oxyfiring with fuel flexibility CO 2 separation Scale-up criteria Commercial scale Flexi-burn TM CFB technology in >500 MW e size
Secondary air flue gas to stack n n+1 n-1 n-2 3 2 1 Primary air Oxy-CFB Testing and Development Bench scale Pilot scale Boiler scale ŁAGISZA 460 MWe supercritical OTU CFB EXPERIMENTAL SCALES 1D-MODEL n v b exp( A/ T )( d / d ref ) MODELS AND DESIGN TOOLS Model analyses Volatile, moisture release CO combustion Mixing Char combustion dyco kef YCO d t k /(1/ ) ef 1 k CO m dmc n rc kmc X O2 dt Figure 2 Furnace heat flux kw/m 2 Models for phenomena 1-D Process models kw/m 2 3-D Process models
Oxy-CFB Experiments VTT 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 O 2 + recycled flue gas - Combustion with bottled gases - Air firing Bench scale BFB/CFB reactor (< 1 kw) suitable for studies of oxygen combustion phenomena PILOT SCALE CFB COMBUSTOR FTIR sampling port Flue gas G as analysat or recirculation Bag filter Gas cooling Observation port To stack Sampling port Zone 4 Sampling port Sampling port Sampling port Fuel container s 1 and 2 Additive container Deposit probe port Secondary cyclone Primary Sampling port cyclone FTIR sampling port Zone 3 Sampling port Zone 2 Zone 1 Secondary gas O2, CO2, N2 M PC control and data logging system Primary gas heating Sampling port Air
Oxy-CFB Experiments Emissions in Pilot Scale Tests SO 2 Emissions and Calcium Utilization with Bituminous Coal NO Emissions with Bituminous Coal
Furnace Height [m] Heat Fluxes of the CFB Furnace are Favourable for Oxycombustion 3D Modelling Results Air combustion Oxy Combustion 50 45 40 35 30 25 20 15 10 5 0 0 100 200 300 400 Heat flux (average) [kw/m²] CFB furnace PC furnace Comparison of heat fluxes in CFB and PC Air Combustion
Flexi-Burn TM CFB Boiler Development Summary 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 MW e CFB boiler has been used as a reference in oxycombustion case studies (retrofit & greenfield Flexi-burn TM 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 www.oxygenie.com 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
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