Design, Construction, and Commissioning of a Pilot-Scale Dual Fluidized Bed System for CO 2 Capture 5 th IEA-GHG Network Meeting September 2013 Robert Symonds*, Dennis Lu, and Scott Champagne CanmetENERGY Natural Resources Canada
Presentation Overview Bench-scale research Pilot-scale activities Current status of operating pilot-plants CanmetENERGY 0.1MW th facility Experimental setup Operating conditions Current research programs Future pilot-scale activities
Bench-scale Research The FBC&G group at CanmetENERGY have been researching calcium looping technologies for CO 2 capture for over a decade now. The focus has been on pretreatment and reactivation techniques to improve sorbent performance: Deep thermal sintering Hydration Pelletization Steam enhancement Doping (organic acids / halogens)
Calcium Looping Pilot Plants Status Several pilot-scale facilities are now on-line ranging from 0.1 to 1.7M th Includes pilot plants at CanmetENERGY, INCAR-CSIC, IFK, Darmstadt (EST), LaPereda, etc. Facilities are operated under varying conditions: CFB versus BFB Different heat sources (electric heaters, solid fuels, ect.) With and without flue gas recycle Carbonation using real versus synthetic flue gas Different methods of solids looping control Ranging solids residence times and Ca to CO 2 ratios Wide range of sorbents and particle sizes Etc. CanmetENERGY objective Design a pilot-scale facility that is capable of operating over a wide range of conditions and configurations
CanmetENERGY 0.1MW th CaL Facility Originally commissioned in 2006, with first continuous CO 2 capture experiments in 2007. Several issues related to continuous operation: Difficult to control solids transfer between reactors Gas bypass between reactors Transfer from calciner to carbonator only via overflow System re-designed to overcome issues and improve flexibility. Designed and constructed in early 2012, with commissioning trials completed in Aug/Sept 2012. Various experimental tests programs since Fall 2012.
CanmetENERGY 0.1MW th CaL Facility
CFBC FUEL HOPPER Vent (>90% CO2) Solids Loading Flare RECYCLE GAS COOLER / CONDENSER FLUE GAS COOLER / CONDENSER Vent FLUE GAS RECYCLE GAS CFBC CYCLONE SOLIDS TRANSFER BFB CONDENSATE KO CONDENSATE KO LINE CYCLONE Water CYCLONE Water Key Features Solids Loading 1 Calciner CFBC SORBENT HOPPER (LIMESTONE / DOLOMITE / PELLETS) 2 Carbonator CFBC CROSS CONVEYER Bottled Gases BFB to CFBC TRANSFER CONVEYER Steam 3 Feed Hoppers B CONE VALVE Solids Loading A 4 Recycle Loop SOLIDS DISCHARGE TRANSFER CONVEYER LOOP SEAL 5 Solids Transfer C Bottled Gases /O2 RECYCLE BLOWER Steam D EDUCTOR E
5 Calciner (1) Fuel delivery Water cooled screw Coal, coke, biomass (2) Feed gases, O 2, recycle flue, mixed gases, steam, etc. (3) Solids transfer Overflow / loop seal to eductor Transfer conveyor (4) Solids discharger (5) Gas analysis O 2, CO 2, CO, SO 2, NO x (6) Electric heaters 16 x 2.5kW (7) Temperature / pressure ports x11 6 3 7 2 1 3 4
Carbonator 4 (1) Feed gases, simulated flue gas, simulated syngas, mixed gases, steam, etc. (2) Solids transfer Overflow to transfer conveyor From eductor transfer cyclone (3) Solids discharger Transfer auger (4) Gas analysis O 2, CO 2, CO, SO 2 (5) Electric heaters 10 x 2.5kW (6) Temperature / pressure ports x9 6 5 2 3 2 1
3 NG Burner / Combustor (1) Feed gases, simulated flue gas, simulated syngas, mixed gases, steam, etc. (2) NG burner NG and air mixture Includes flame scanner, ignitor, and view port (3) Flue gas Pumped to carbonator (4) Moisture analyzer 0-100% H 2 O (5) Fuel delivery Water cooled screw Coal, coke, biomass (6) Temperature / pressure ports x2 2 6 4 5 1
CanmetENERGY 0.1MW th CaL Facility Technical Data & Operating Conditions Calciner Temperature 850 to 920 o C Pressure atmospheric ID = 0.1 m H = ~5.1 m SV = 0.5 to 4 m/s Fuel feed rate = 2 to 10 kg/h Particle size range = 100 to 850 micron Operation Full oxy-fuel operation with flue gas recycle (both wet and dry) Concentrated CO 2 flue gas stream of up to >90% Flexibility to run a variety of fuels and feed gases including steam Solids transfer via overflow or loop seal CFB or BFB Carbonator Temperature 550 to 700 o C Pressure atmospheric ID = 0.1 m H = ~3.0 m SV = 0.5 to 2 m/s Particle size range = 100 to 850 micron STR = 20 to 50 kg/h Ca to CO 2 ratio = 8 to 25 Operation Continuous CO 2 capture using a variety of calcium based sorbents Capable of CO 2 capture efficiencies >90% Flexibility to operate with different feed gases (real or synthetic flue gas, syngas, steam)
CanmetENERGY 0.1MW th CaL Facility Current Research Activities System commissioning Natural limestone Verified suitable oxy-fuel operating conditions (>90% CO 2 ) are achievable Determined optimum solids transfer conditions: Controllable transfer rate No gas bypass between reactors Flexibility to transfer solids via overflow and loop seal allowing for the utilization of larger sorbent PSD Continuous CO 2 capture for extended duration: Varied carbonation temperature and solids inventory to achieve desired capture efficiency Modified sorbent testing Goal: Take sorbents with promising characteristics (improved cyclic stability, modified morphology, attrition resistance, etc.) at the bench-scale and test them at the pilot scale: Pelletized materials Reactivated sorbents through modified hydration/dehydration techniques
CanmetENERGY 0.1MW th CaL Facility Current Pilot-Scale Activities Steam addition during carbonation and calcination Previous experimentation performed by CanmetENERGY, at both the bench-scale and pilot-scale, has shown considerable CO 2 capture improvements via the addition of steam. Steam addition during calcination also improves sorbent performance at the bench-scale By adding steam to the calciner, it is also possible to lower the calcination temperature (reduced sintering a major factor in sorbent deactivation) Design, fabrication, and commissioning of a BFB combustor Allow for the generation of real flue gas Initially using natural gas and eventually capable of burning solid fuels Examine the impact of impurities (SO 2, halogens, ect.) on sorbent performance Verify the impact of steam on CO 2 capture enhancement
CanmetENERGY 0.1MW th CaL Facility Future Pilot-Scale Activities H 2 O 2-Depleted CaCO 3/CuO CO 2 Chemical Looping Using a metal oxide, such as Cu/CuO as an oxygen carrier Modify the existing calcium looping pilot-plant to facilitate an air reactor Several reactor configurations are possible Also, possible sorbent preparation techniques could be employed to combine both CO 2 and O 2 carriers. Fuel Steam Fuel Steam Gasifier Gasifier Ash Syngas CaCO 3/Cu H 2 Carbonator CaO/Cu Reactor Reactor Regenerator O 2-Depleted CO 2 MgCO 3/CuO Regenerator H 2 / CH 4 / Biomass MgO/Cu Ash MgCO 3/Cu H 2 / CH 4 / Biomass MgO/Cu/CuO
Acknowledgements Funding for this work was provided by Natural Resources Canada through the Program of Energy Research and Development (OERD).
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