Carbonation-Calcination Reaction(CCR) Process for High Temperature CO 2 and Sulfur Removal Shwetha Ramkumar, William Wang, Dr. Songgeng Li, Siddharth Gumuluru, Zhenchao Sun, Nihar Phalak, Danny Wong, Mahesh Iyer Dr. Robert M. Statnick, Dr. L.-S. Fan William G. Lowrie Department of Chemical and Biomolecular Engineering The Ohio State University Columbus, Ohio, USA Bartev Sakadjian Babcock and Wilcox Power Generation Group 1 st Meeting of the High Temperature Solid Looping Cycles Network September 15 th September 17th U.S. Patent Application No. 61/116,172
CO 2 Capture from Fossil Fuel Based Plants Post Combustion Electricity CO 2 free Flue Gas Coal Or Natural Gas Boiler Steam Generator CO 2 Capture Oxy Combustion Coal Or Natural Gas Air ASU Boiler Electricity Steam Generator CO 2 Compression, Transportation and Sequestration Gas Coal Gasifier Cleanup or Natural Reformer Gas Electricity Pre Combustion WGSR Gas Turbine Steam Turbine N 2 and Steam CO 2 capture PSA FT Reactor Hydrogen Ammonia Synthesis Hydrogenation Other chemicals synthesis Liquid Fuels
General Overview Coal-fired power plants generate 50% of electricity in United States and accounts for 33% of United States CO 2 emissions Generate 41% of world s electricity and accounts for 42% of world s CO 2 emissions Necessary to develop economic, post-combustion CO 2 removal technology for existing power plants to sustain energy demand while protecting environment Solvent based scrubbing oxyfuel adsorbents Membranes reactive sorbents U.S. Patent Application No. 61/116,172
Concept of the CCR Process Use of metal oxide (CaO) in a reaction-based cyclical capture cycle Carbonation: CaO + CO 2 CaCO 3 Sulfation: CaO + SO 2 + ½ O 2 CaSO 4 Calcination: CaCO 3 CaO + CO 2 Advantages of Carbonation/Calcination Reaction (CCR) Operation under flue gas conditions High equilibrium capacities of sorbent Calcination produces pure CO 2 stream Low sorbent cost Simultaneous CO 2 /SO 2 removal High-temperature operation allows for heat utilization
Demonstration Project Team Organization Ohio State University Clear Skies Consulting AEP Babcock & Wilcox Carmeuse CONSOL Energy Duke Energy First Energy Littleford Day Roles Project Lead, Testing, Data Analysis Project Manager Collaborator Collaborator Collaborator Collaborator Collaborator Collaborator Collaborator Shell Global Solutions Collaborator U.S. Patent Application No. 61/116,172
Basic Reactions Based on high-temperature, reversible reaction of metal oxide (CaO) Waste CaO/CaCO CO 2 /SO 2 Lean Flue Gas 3 /CaSO 4 Energy Particulate CaO/CaCO 3 / Recycle CaO/ Capture Purge CaSO Device 4 CaCO 3 /CaSO 4 CARBONATOR Dehydration Ca(OH) 2 CaO + H 2 O Carbonation Energy CaO + CO CaCO 2 3 Sulfation CaO + SO 2 + 1/2 O 2 CaSO 4 Energy 450 C 650 C Flue Gas Boiler HYDRATOR Particulate Ca(OH) 2 / Capture CaSO CaO + H 2 O Ca(OH) 2 Device 4 500 C, P ~ 1 atm Fly Ash H 2 O Fresh CaCO 3 CALCINER Calcination CaCO 3 CaO+CO 2 900 C 1200 C CaO/ CaSO 4 CO 2 to sequestration
Process Flow Diagram of the CCR Process Carbonator Co 2 Free Flue Gas Fresh Sorbent Spent Sorbent Purge Pure CO 2 Calciner Flue Gas Calcined sorbent Bag House Steam Hydrator Boiler Coal Air
Single cycle (once-through) testing Multiple sorbents Solids loading (Ca:C ratio) Residence time Reaction Temperature
Sub-pilot Plant Set-up Clean Flue Gas To Atmosphere Sorbent Injection Gas sampling system Coal Stoker Baghouse
CO 2 Removal by Ca Based Sorbents % CO 2 Removal 100 90 80 70 60 50 40 CO 2 Removals for Calcium-Based Sorbents Calcium Hydroxide Pulverized Ground Lime Ground Lime Log. (Calcium Hydroxide) Linear (Pulverized Ground Lime) Linear (Ground Lime) 30 20 10 0 0 0.5 1 1.5 2 2.5 3 3.5 4 Ca:C Mol Ratio U.S. Patent Application No. 61/116,172
100 SO 2 Removal by Ca-based Sorbents SO 2 Removals for Calcium-based Sorbents 98 96 94 % SO 2 Removal 92 90 88 86 84 82 Calcium Hydroxide Pulverized Ground Lime Ground Lime 80 0 0.5 1 1.5 2 2.5 3 3.5 4 Ca:C Mol Ratio U.S. Patent Application No. 61/116,172
Effect of Residence Time 100 CO 2 Removal vs. Reaction Residence Time 90 80 70 CO 2 Removal (%) 60 50 40 30 20 10 0 Relative Residence Time 1/2 2/3 1
Multicyclic Testing
Calcination under Realistic Conditions 70 70 60 Wt% Capture 60 50 40 30 20 Wt% Capture 50 40 30 20 10 10 0 Original Sorbent 0% 33% 50% 0 Original Sorbent 1 2 3 Steam Concentration in Carrier Gas Number of Cycles Sorbent reactivity reduced to half during calcination Effect of sintering reduced by steam calcination Increase in steam concentration improves reactivity Calcination at 900C with 50% steam and 50% CO 2 Reduced sintering over multiple cycles Reactivity reduced to half in 4 cycles U.S. Patent Application No. 61/116,172
CCR with hydration 60 Wt % Capture 50 40 30 20 Sorbent reactivity reduced to a third after calcination at 1000C Calcined sorbent regenerated completely by hydration 10 0 Original Sorbent Calcined Sorbent Water Hydration Steam Hydration U.S. Patent Application No. 61/116,172
Cyclic Studies Set-up Sorbent Injection Baghouse Rotary Calciner Coal Stoker
Multicyclic CO 2 and SO 2 Removal 100 90 80 70 % CO 2 Removal 60 50 40 30 20 10 0 0 1 2 3 4 5 Cycle Number U.S. Patent Application No. 61/116,172
Aspen Simulation Assumptions 500 MWe power plant Coal Composition: Pittsburgh #8 20% Excess Air 41% Turbine Efficiency 10% in-house electricity consumption 119 kwh/tonne CO 2 for compression to 14 MPa (~140 atm) 1 Parasitic Energy Consumption = ( Net Electricity Generation w/o CO2 Control) ( Net Electricity Generation w/co2 Control) * 100 Net Electricity Generation w/o CO2 Control 1. Wong, S. CO 2 Compression and Transportation to Storage Reservoir. Asia-Pacific Economic Cooperation. Building Capacity for CO 2 Capture and Storage in the APEC Region. Module 4 U.S. Patent Application No. 61/116,172
Aspen Simulation of CCR Process Pittsburgh #8 Coal, 1506.84 MWth input 1.33:1 Ca:C mol ratio 90% CO2/100% SO2 removal 3% purge stream Temperature (C) 698.7 MWth from Boiler 647.6 MWth from CCR 90% Heat Extraction 582.8 MWth 41% Turbine efficiency Pressure (atm) Mass Flow Rate (tons/hr) Duty (MW) 525.4 MWe Gross 10% in-house consumption Q Duty (MW) 472.8 MWe 51.3 MWe compression (119 kwh/tonne CO2) 421.5 MWe NET Parasitic Energy Consumption = 15.8% COAL B-DECOMP B-BURNIN COAL 205 tons/hour PRI B-ASEP AIR B-AIR 2465 tons/hour BOILER SEC B-BURNER PRI-IN QAIR BOI-FLU SEC-IN STACKFLU CO2/SO2 Lean Flue Gas to Stack Q HEAT-1 Q-BOI 246.9 Q-CAL Q-CAL FLU-GAS APH-FLU Q 232.5 HEAT-2 Q-GAS Q HEAT-3 394.1 ASH PCD FLU-ASH ASH ASH Q-ASH ASH-OUT Ash FLUNOASH S T E A M T U R B I N E Q -0.0 HEAT-4 CO2/SO2 REMOVAL CO2-S02 CAOH2 CAR-SORB SORB-SEP SEP-SORB RECYCLE FLU-OUT H-PURGE PURGE QCAL AIR1 PURGE/ RECYCLE CaCO3 64 tons/hour AIR2 PURGE SORB-MIX SORBMIX CALCINER AIR1 CACO3 CAL-OUT AIR2 Purge CAO-SEP 219.3 HEAT-5 CAL-NEW CAL-CO2 Q ECON CALCINER Q HEAT-6 Q-CO2 172.7 HEAT-7 80.8 Q CO2-OUT REGEN CAO Q-CAO CAL-CAO CO2 to Sequestration CO2 CO2 15% - 20% Parasitic Energy Consumption (with compression) U.S. Patent Application No. 61/116,172
Overall Electricity Production Efficiency Net Efficiency, HHV (%) 50 45 40 35 30 25 20 15 10 5 0 Air Fired SC/Air* Base Air Fired USC/Air* Econoamine SC/Air* Oxy Fuel SC/ASU* CCR SC/Air *Ciferno et al. 2008 Sakadjian et al, 2009
Conclusions Greater than 90% CO 2 and ~100% SO 2 Removal at a C:C of 1.3 Ca(OH) 2 has highest reactivity leading to low Ca:C and residence time 13 hours of continuous operation conducted and repeatable results obtained Sorbent reactivity maintained constant over multiple cycles Reduction in sorbent circulation and make up rate Low parasitic energy requirement of 15% -20% for CCR depending on heat integration Competitive with existing CO 2 control technologies
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