Energy Systems Analysis Group Activities Bob Williams CMI Annual Meeting Princeton University 9 February 2010

Toward Decarbonization of Coal Power US coal power accounts for: – ½ of electricity –⅓ of CO 2 emissions from fossil fuel burning Decarbonizing existing coal plant sites warrants priority under serious C-mitigation policy Options considered: –CCS retrofit for pulverized coal plant (PC-CCS retrofit) –Four repowering options Definitions: –Retrofit: retain plant but add equipment to “scrub” CO 2 from flue gases –Repower: bulldoze site and rebuild there—but retain all infrastructure…or rebuild elsewhere if site unsuitable

Carbon Mitigation Options Examined Written-off PC-V plant543 MW e, 33.6% efficient CCS retrofitPost-combustion capture (amine scrubber) Repowering options NGCC-VNatural gas combined cycle that vents CO 2 NGCC-CCSNGCC with post combustion capture CIGCC-CCSCoal integrated gasifier combined cycle with pre-combustion capture CBTLE-CCSCoal/biomass to liquids + electricity with pre- combustion capture

Outputs: Fischer-Tropsch liquid fuels (~ 2/3 energy out = synthetic diesel/gasoline) + electricity (~ 1/3 energy out from combined cycle) ~ ½ feedstock C captured as CO 2, stored in geological media GHG emission rate declines as biomass % of energy input increases Configuration considered: 7,800 B/D of FTL MW e (net) 1 x 10 6 dt/y = 38% of input (energy basis, HHV) 2.1 x 10 6 t CO 2 stored annually GHG emissions are ~ 90% < for conventional energy displaced (existing coal power + equivalent crude oil-derived products) Repowering via Coal/Biomass Coproduction of Liquid Fuels + Electricity with CCS (CBTLE-CCS)

LEVELIZED ELECTRICITY GENERATION COST vs GHG EMISSIONS PRICE

THOUGHT EXPERIMENT: DECARBONIZE 90% OF EXISTING COAL POWER, (9.4 GW e /y) CBTLE-CCS coproduct: 3.9 million barrels/day of low-C synfuels 0.5 Gt biomass needed annually by 2050 for repowering option NG generation up 2 X, (assumed make-up power:NGCC-CCS)

FUTURE WORK Potentially abundant, ubiquitous shale gas at reasonable cost  extend coproduction idea CBTLE-CCS  GBTLE-CCS Extend analysis to China—exploring prospects for both as alternatives to continued building of PC-V plants

ESAG TEAM AND MAIN COLLABORATORS, Core Group: –Robert Williams –Eric Larson –Tom Kreutz –LIU Guangjian –ZHENG Zhong China Collaborators –LI Zheng (Tsinghua) –CHEN Haiping (NCEPU) –GUO Xianbo (SINOPEC) –ZHOU Zhe (Tsinghua) Politecnico di Milano collaborators: –Stefano Consonni –Emanuele Martelli –Giulia Fiorese ECN, The Netherlands –Michiel Carbo