OPTIMISATION OF COAL FIRED POWER PLANT PERFORMANCE WHEN USING FLUE GAS SCRUBBERS FOR CO 2 CAPTURE

Transcription

1 BCURA PROJECT B70 AUGUST JANUARY 2005 OPTIMISATION OF COAL FIRED POWER PLANT PERFORMANCE WHEN USING FLUE GAS SCRUBBERS FOR CO 2 CAPTURE The Coal Research Forum Autumn Meeting 2005 The presentation of current projects funded through the BCURA/DTI programme Wednesday 14th September 2005 British Sugar plc. Conference Centre, Holmewood Hall, Peterborough Jon Gibbins, Bob Crane Imperial College London Des Dillon Mitsui Babcock Energy Ltd Page 1

2 FLUE GAS CONDENSATE FROM CO2 SOLVENT SOLUTION REFLUX CONDENSERS BOILER FEED WATER FROM CONDENSER CO2 BOILER FEED WATER COOLING WATER GAS TO STACK LEAN/RICH HEAT EXCHANGER POWER FOR CO2 COMPRESSOR FWH INTERCOOLER COOLING WATER INTERCOOLER SCRUBBER STRIPPER BLOWER REBOILER STEAM FOR CO2 RELEASE FLUE GAS FROM FGD PLANT FLUE GAS COOLER COMPRESSED CO2 FOR EXPORT BOILER FEED WATER TO FWH5 AMINE CO 2 CAPTURE SYSTEM PROCESS FLOW DIAGRAM Page 2

3 POST COMBUSTION CAPTURE STATE OF THE ART BEFORE PROJECT Leading options for the capture of CO2 at power stations, IEA GHG 3/14, February 2000 Page 3

4 STEAM EXTRACTION FROM POWER PLANT TURBINE with poor solvent and no integration can reduce efficiency by >12 percentage points Desuperheat with reboiler condensate Steam offtake valve Steam to reboiler Back pressure valve to maintain IP exit pressure HP cylinder Alstom Large Steam Turbines brochure IP cylinder LP cylinder LP cylinder Page 4

5 SIX RULES FORMULATED TO FILTER OUT INAPPROPRIATE POST COMBUSTION LITERATURE AND GUIDE IMPROVED PLANT DESIGN STUDIES 1. Add heat to the steam cycle at as high a temperature as possible (i.e. be prepared to use best available steam conditions if commercially justified). 2. Reject heat from the steam cycle, in the steam extracted for solvent regeneration, at as low a temperature as possible. 3. Produce as much electricity as possible from any additional fuel used, consistent with rejecting heat at the required temperature for solvent regeneration. 4. Make use of waste heat from CO 2 capture and compression in the steam cycle. 5. Use the latest solvent developments. 6. Exploit the inherent flexibility of post-combustion capture. Page 5

6 HEAT INPUT FROM BOILER HP IP LP G HEAT TO CONDENSER COOLING WATER FWH7 FWH6 DEAERATOR FWH5 FWH4 FWH3 FWH2 FWH1 LPFWH HEAT RECOVERY SPRAY DESUPERHEATER LIQUID VAPOUR HEAT FOR CO2 RELEASE REBOILER HEAT FROM COMPRESSOR INTERCOOLERS HEAT FROM CO2 REFLUX CONDENSERS IMPROVED OPTIONS FOR REMOVING STEAM AND RECOVERING WASTE ENERGY Page 6

7 LHV efficiency penalty (percentage points) BENEFIT OF APPLYING THE RULES TO IEA GHG PH3/14 RESULTS Plant configuration No capture MEA no integration MEA+ HPFWH MEA+ LPFWH MEA+ HPFWH+ LPFWH KS2 no integration KS2+ HPFWH KS2+ LPFWH KS2+ HPFWH+ LPFWH Extra MW CO2 emitted (tonne/hr) Generation efficiency (%LHV) Capital cost ($/kw) Capital charges (c/kwh) Cost of fuel (c/kwh) Other costs (c/kwh) Cost of electricity (c/kwh) Rule 2 Rule 4 Page 7 Rule 5 Gibbins, Crane, JPE, 2004

8 POST COMBUSTION AND IGCC COMPARISON Page 8

9 POST COMBUSTION AND OXYFUEL COMPARISON Page 9

10 TWh Estimates for future Chinese electricity generation and associated CO 2 emissions based on Guo Yuan and Zhou Dadi, Low emission options in China's electric power generation sector, ZETS Conference, Brisbane, Feb renewable nuclear hydropower natural cogeneration natural gas generation oil clean coal new prior coal fired cogeneration new prior coal generation existing coal fired cogeneration existing coal generation MARKET FORCES DOMINANT TECHNICALLY FEASIBLE DEVELOPMENT Total UK CO 2 emissions 2000 Mt CO Page

11 CCS IN G8 GLENEAGLES COMMUNIQUE Page 11

12 GENERAL PRINCIPLES FOR CAPTURE READY POWER PLANT Fundamental requirements a) Sufficient space on site and in critical access locations to add CO 2 capture plant and necessary internal interconnections. b) Design study for adding CO 2 capture, to assess technical feasibility and costeffectiveness. c) CO 2 storage option(s) Plus optional pre-investments, depending on economic justification. Possible pre-investment options for pulverised coal steam plant are: Build capture ready IGCC (i.e. not just ordinary IGCC) instead of capture ready pulverised coal steam plant For post combustion capture: a) High efficiency (or upgradeable) FGD (if FGD is required) b) Turbine modifications to facilitate steam extraction For oxyfuel capture: a) If an FGD is fitted, verify operation under oxyfuel conditions b) Support tie-ins for heaters and recycle ducts c) Provision for fans to operate under changed flows Page 12

13 PRELIMINARY BREAKDOWN FOR ADDITIONAL COE WITH CAPTURE Additional COE (CAD/MWh) Turbine mismatch O&M Consumables Capture capital Efficiency penalty ~ Fluor ~ MHI Page 13 Max Ball, Bob Stobbs, Larry Ward, Jon Gibbins and Malcolm Wilson, A new 'capture ready' power plant project in Saskatchewan, 4 th Ann. Conf. on Carbon Seq.,Alexandria VA, May 2-5, 2005.

14 POSSIBLE BENEFITS FOR MAKING PLANTS CAPTURE READY Adding capture to: Capture ready Capture un-ready IGCC PC IGCC PC Original efficiency %LHV 40.0% 42.0% 40.0% 42.0% Efficiency penalty %LHV 6.5% 8.5% 7.5% 9.5% Additional electricity cost for reduced output 19.4% 25.4% 23.1% 29.2% Capture plant capital cost ($/kw, % above original) 30.0% 50.0% 45.0% 75.0% Capture plant capital cost as % of original capital cost 10.6% 24.6% 21.9% 45.8% Capture plant capital cost contribution to electricity cost for original fuel cost fraction shown 30% 7.4% 17.2% 15.3% 32.0% Loss of 1 year production added to next 20 years at 10% discount rate, % of cost/yr 11.7% 8.2% 8.2% Fuel cost fraction (avoided costs) 30% Total additional electricity cost, based on ORIGINAL cost for THAT technology 26.8% 42.6% 46.6% 69.5% Bigger increase in electricity cost to add capture to PC, but initial electricity cost for IGCC probably higher But this is for current post-combustion capture and IGCC technology changes possible Page 14

15 Refereed Journal Papers Gibbins, J. and Crane, R., "Scope for reductions in the cost of CO2 capture using flue gas scrubbing with amine solvents", Proc. I.Mech.E, Vol. 218, Part A, J. Power and Energy (2004), Gibbins, J. and Crane, R., A preliminary assessment of electricity costs for existing PF plant retrofitted with an advanced supercritical boiler and turbine and solvent CO 2 capture, Proc. I.Mech.E, Vol. 218, Part A, J. Power and Energy (2004). Refereed Conference Papers Gibbins, J.R., Crane, R.I, Lambropoulos, D., Booth, C., Roberts, C.A. and Lord, M., "Maximising the effectiveness of post combustion CO 2 capture systems", Proc. GHGT7, Vancouver, Sep Roberts, C.A., Gibbins, J.R., Panesar, R. and Kelsall, G., "Potential for improvement in power generation with post-combustion capture of CO 2 ", Proc. GHGT7, Vancouver, Sep Other conference papers etc. Gibbins, J. and Crane, R., "Reducing the cost of CO 2 removal using solvent scrubbing", CRF Autumn Meeting 2003, The presentation of current projects funded through the BCURA/DTI programme, Tuesday 2nd December 2003, Alstom Power Ltd., Whetstone. Gibbins, J. and Crane, R., "Principles and performance limits for integrating amine scrubbing with coal and gas fired power plants", in Report on 6th Workshop, International Test Network for CO 2 Capture (8-9 March 2004, Trondheim, Norway), IEA GHG Report Number PH4/28, May Gibbins, J. and Crane, R., "Criteria for economically-competitive post-combustion CO 2 capture from pulverized coal power plants", Proc. 3rd Ann. Conf. on Carbon Sequestration, Alexandria VA, May Gibbins, J.R., Crane, R.I., Lambropoulos, D., Man, C. and Zhang, J., "Making pulverised coal plant 'capture ready': methods and benefits", Proc. 7th International IEA GHG CO 2 Capture Network Workshop, Vancouver, 10 September 2004, IEA GHG Report Number PH4/34, Oct Ball, M., Stobbs, R., Ward, L., Gibbins, J. and Wilson, M., "A new 'capture ready' power plant project in Saskatchewan", Proc. 4th Ann. Conf. on Carbon Sequestration, Alexandria VA, May Gibbins, J.R, "Opportunities for research into near-term capture options for pulverised coal plant in China", Stanford GCEP project workshop on technical issues and challenges associated with advanced coal use integrated with CO 2 capture and storage in China, Tsinghua University, Aug. 22 and 23, Page 15

16 CONCLUSIONS AND FUTURE WORK Viable pulverised coal capture option demonstrated, confirmed in studies with BCURA industrial sponsors Helped established UK lead in pulverised coal with CCS new studies for UK and North American markets, possibly China Capture ready and retrofit options for the large number of pulverised coal plants contributing to UK policy objectives on climate change mitigation Potential for further studies on post combustion capture fundamentals with Canada and other overseas collaborators Need to improve UK capabilities if any of the existing UK coal power plant fleet is to be converted to CO 2 capture - people (including PhD students) - independent expertise on existing and future commercial CO 2 capture systems - how to design and exploit flexible CCS systems to make money Page 16

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19 Pre-combustion capture ready Problem for IGCC, if gas turbine is matched to gasifier and oxygen plant before capture is added Easier for chemical plants, especially if making hydrogen Possible alternative for IGCC have shift from the start and recover the losses GASIFIER Page 19

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21 KIER Flue Gas Clean-up Technology Center Establishment of Facility for the Development of Flue Gas Clean-up Technologies Page 21