Comparison of a New Warm-Gas Desulfurization Process versus Traditional Scrubbers for a Commercial IGCC Power Plant

Transcription

1 Comparison of a New Warm-Gas Desulfurization Process versus Traditional Scrubbers for a Commercial IGCC Power Plant Jerry Schlather Eastman Chemical Company Brian Turk RTI International Gasification Technologies Conference October 17, 2007

2 Warm Syngas Cleanup Technologies Regenerable ZnO sorbents Sulfur Transport reactor Direct Sulfur Recovery Process HCl adsorbents (disposable) Hg adsorbents (disposable) As adsorbents (disposable) Se adsorbents (disposable) Regenerable NH 3 /HCN adsorbents Regenerable CO 2 sorbents Operating Temperatures > 250 C

3 Transport Desulfurization Reactor System Pressure: psig CLEAN SYNGAS CYCLONE SO 2 / N 2 TO SCRUBBER OR DSRP CYCLONE RISER ZnO + H 2 S ZnS + H 2 O ZnO + COS ZnS + CO 2 ( ºF) SULFIDED SORBENT STANDPIPE ZnS + 3/2O 2 ZnO+SO 2 ( ºF) RISER STANDPIPE Sulfur Recovery Options Direct Sulfur Recovery Process (DSRP) Sulfuric Acid Modified Claus Process REGENERATED SORBENT SOLIDS WITHDRAWAL TO REGEN LOOP REGENERATED SORBENT TO ABSORBER MIXING ZONE MIXING ZONE RAW SYNGAS SORBENT RECYCLE N 2 /O 2 MIXING ZONE

4 Installed Pilot Plant Systems Eastman's Kingsport, TN Coal Gasification Facility Direct Sulfur Recovery Process (DSRP) Warm Gas Desulfurization System (WGDS)

5 Typical Sulfur Concentrations in Effluent Syngas 4.0 Effluent S concentration (ppmv) H 2 S Removal > 99.97% COS Removal > 99.96% SO hours Dirty syngas composition: 7,771 ppmv H 2 S 440 ppmv COS

6 Desulfurization Process Reliability 30 min Averages H 2 S/ COS removal > 99.95% Sulfur Rate, lb/hr Desulfurization rate Regeneration rate 95 hours On-Stream Factor 61% (Several auxiliary equipment failures) [Feb '07 to May '07] 81% (Main faulty auxiliary equipment removed) [May '07 to Present]

7 Desulfurization Pilot Plant Summary of Parametric Testing Total of 3,017 hr of syngas operation Pressure, psig Inlet Concentration, S ppmv 8,661 7,023 8,436 Effluent Conc. S ppmv Range S Absorbed, lb/hr S Removal, % All data are averages over multiple hours of operation

8 Progress in : Parametric Testing Program Operating conditions Effluent sulfur concentrations over target operating conditions Regeneration exotherm Sorbent Active life Attrition ~5-50 lbs/mm lbs circulated [FCC ~ lbs/mm circulated] 5 Operating/control procedures 0 Stable solids circulation Thermally neutral process operation Effluen Sulfur Conc. (ppmv) Residence Time [sec] R 2 = Commercial startup/shutdown procedures

9 Direct Sulfur Recovery Process (DSRP) Summary Chemistry SO 2 + H 2 1/n S n + H 2 O Operation ~115 hr on-stream to date Up to 98 % sulfur recovery demonstrated Highly effective and stable catalyst On-stream time limited Frequent plugging of small diameter sulfur lines

10 Treating Syngas Contaminants beyond Sulfur Modular fixed bed technologies for syngas cleaning beyond sulfur at temperatures > 200 ºC Regenerable fixed-bed ammonia process Inexpensive disposable HCl sorbents Disposable fixed-bed sorbents for trace contaminants Hg As Se Multifunctional sorbents NH 3 concentration (ppmv) Cycle #1 Cycle #2 Cycle #3 Cycle # Time (min)

11 Technology Readiness for Commercial Deployment Performance in real syngas Field testing has provided actual performance resulting from exposure to real coal-derived syngas Process reliability Sorbent performance Extended testing to evaluate long-term chemical deactivation and mechanical attrition Process control and stability Demonstrated and refined ability to control process at stable operating conditions Sorbent production scale-up Commercially manufactured 8,000 lbs of sorbent for pilot-plant testing Process scale-up Successfully scaled process up to 0.3 MW Actively working on a 50-MW demonstration unit Modular fixed bed cleanup technologies for additional syngas contaminants Fixed bed adsorbents for HCl, NH 3, As, Hg, and Se

12 Application of RTI/Eastman Warm Syngas Cleaning Platform POWER PRODUCTION Raw Syngas from Gasifier CHEMICAL PRODUCTION Warm Cleanup

13 Commercial Design & Economics Design Basis for Comparison of Warm Gas Clean-Up (WGCU) Technologies vs. Traditional Scrubbers Illinois No. 6 Coal (2006 DOE, preliminary) U.S. Midwest site Nominal 600 MW capacity GE Gasification Radiant Cooling Conventional cryogenic ASU without integration to GT GE 7FB based power train

14 Design Basis Different Elements Base Case Warm Gas Clean-Up Gas Quench & Scrubbing Low Temp. Gas Cooling Selexol AGR Claus sulfur recovery with SCOT tail gas treating Ambient Temperature Mercury removal Convective Cooler Warm Gas Desulfurization Process (WGDS) Direct Sulfur Recovery Process (DSRP) High Temperature Mercury Removal Process SCR (no LT cooling to remove NH 3 ) Independent Technical analysis performed by Nexant using WGCU design provided by RTI & Eastman

15 Performance Comparisons IGCC IGCC with Improve Base Case WGCU ment Imports or Feeds Coal Feed, STPD (AR) 5,467 5,467 95% Oxygen, STPD 4,665 4, % 99% N2, STPD 7,024 3, % Make Up Water, GPM 5,646 4, % Exports or Products Electric Power, MW % Sulfur, STPD Slag & Ash, STPD (dry) Waste Water, GPM 2,798 1, % Thermal Efficiency HHV % % LHV % % Efficiency Improved 3.6 points HHV

16 Power Balance IGCC IGCC with Improve Base Case WGCU ment Power Balance, MW Gas Turbine % Steam Turbine % Total Generation % Coal Handling & Slurry Prep % Gasification & Scrubbing % Air Seperation Unit % Oxygen Compression % LT Gas Cooling % AGR / SWS / Sulfur Recovery / TGTU % Plt.Air / Inst. Air / N2 Systems % HRSG/Boiler Plt./ BFW/DM/Cond. Sys % CW Pumps & CT Fans % BOP % Total Consumption % Net Power for Export %

17 Capital Cost Summary IGCC IGCC with CAPITAL COST, $MM Base Case WGCU Coal Handling Gasification Block Air Separation COS Hydrolysis & LT Cooling AGR & Sulfur Recovery Plant Air & N2 Compression Gas Turbine Generators HRSG & BFW Systems Steam Turbine Generator Balance of Plant Home Office Cost Total 1, ,051.1 Net Power Export, MWe Cost per Unit Output, $/KWe 1,904 1,640 $264/KW CAPEX IMPROVEMENT

18 Cost of Electricity Comparison IGCC IGCC with Incomes & Expenses, $MM/yr Base Case WGCU Coal (as received) Catalyst & Chemicals Maintenance Admin & Labor Overheads & Benefits Insurance & Taxes Loan Repayment Investment Recovery Water Import Ash/Slag Disposal Sulfur Sale Total Annual Power Export, GW-hr 4,356 4,773 Cost of Electricity, /kw-hr

19 Conclusions Eastman/RTI Warm Gas Clean-Up technologies: Increase efficiency by 3.6 points HHV Dispatch 56 MWe more power Reduce CAPEX by $264 / KW For 600 MW IGCC Reduce COE by 0.69 /KW-hr Eastman/RTI Pilot Plant testing: Demonstrated technology readiness Achieved performance targets with real syngas Desulfurization Process reliability Long term durability of desulfurization sorbent Successfully scaled up process to 0.3 MW t Successfully scaled up sorbent production (8,000 lbs) Additional fixed bed syngas cleaning options ready for pilot testing (HCl, NH 3, As, Hg, and Se)

20 Acknowledgements US Department of Energy, Office of Fossil Energy USDOE Contract Number DE-AC26-99FT40675 Contracting Officer's Representative: Suresh C. Jain IGCC Technology Manager: Gary J. Stiegel RTI International David Coker, Gary Howe, Santosh Gangwal, Raghubir Gupta Andreas Weber, Paul Box and Gunnar Henningsen Eastman Chemical Company Jeremy Gibson, Danny Bishop, James Leonard, David Denton Nexant Robert Chu, Bruce Degen, and Gerald Choi

21 Questions?