Transcript Slide 1

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 CO2 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” CO2 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 plant
543 MWe, 33.6% efficient
CCS retrofit
Post-combustion capture (amine scrubber)
Repowering options
NGCC-V
Natural gas combined cycle that vents CO2
NGCC-CCS
NGCC with post combustion capture
CIGCC-CCS
Coal integrated gasifier combined cycle with
pre-combustion capture
CBTLE-CCS
Coal/biomass to liquids + electricity with precombustion capture
Repowering via Coal/Biomass Coproduction
of Liquid Fuels + Electricity with CCS (CBTLE-CCS)
• 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 CO2, stored in geological media
• GHG emission rate declines as biomass % of energy input increases
• Configuration considered:
• 7,800 B/D of FTL + 264 MWe (net)
• Biomass @ 1 x 106 dt/y = 38% of input (energy basis, HHV)
• 2.1 x 106 t CO2 stored annually
• GHG emissions are ~ 90% < for conventional energy displaced
(existing coal power + equivalent crude oil-derived products)
•
GHG Emission Rates for Alternative Power Systems
1000
kg CO2eq per MWh e
900
800
700
600
500
400
300
200
100
0
Existing plant
CCS retrofit
NGCC-V
repowering
NGCC-CCS
repowering
CIGCC-CCS
repowering
CBTLE-CCS
repoweriing
GHG Emissions Avoided for Alternative C-Mitigation Strategies
for Existing Coal Plant Sites
1600
kg CO2eq per MWh
1400
1200
1000
Via displacing crude oil-derived products
800
Via displacing existing coal power
600
400
200
0
CCS retrofit
NGCC-V
repowering
NGCC-CCS
repowering
CIGCC-CCS
repowering
CBTLE-CCS
repoweriing
CO2 Storage Rate for Systems with CCS
kg CO2 per MWh
1200
900
600
300
0
CCS retrofit of existing
subcritical PC
Repowering with
NGCC-CCS
Repowerinng with
CIGCC-CCS
Repowering with
CBTLE-CCS
Energy Penalty for CCS
(relative to same system with CO2 vented)
40
Percent
30
20
10
0
CCS retrofit of existing
subcritical PC
Repowering with
NGCC-CCS
Repowerinng with
CIGCC-CCS
Repowering with
CBTLE-CCS
Consumptive Water Requirements,
Gallons per MWhe of Electricity Output
1000
900
Gallons per MWh e
800
700
600
500
400
300
200
100
0
Existing
subcritical PV-C
CCS reetrofit
of existing
subcritical PC
New
NGCC-V
New
NGCC-CCS
New
CIGCC-V
New
CIGCC-CCS
New
CBTLE-CCS
Consumptive Water Requirements,
Gallons per MWhth of Fuel Input
Gallons per MWh th
250
200
150
100
50
0
Existing
subcritical PV-C
CCS reetrofit
of existing
subcritical PC
New
NGCC-V
New
NGCC-CCS
New
CIGCC-V
New
CIGCC-CCS
New
CBTLE-CCS
Capital Cost for Alternative C-Mitigation Strategies
for Existing Coal Plant Sites
1600
Million Dollars
1400
1200
1000
Makeup via NGCC-CCS
800
Retrofit or Repowering
600
400
200
0
CCS retrofit
NGCC-V
repowering
NGCC-CCS
repowering
CIGCC-CCS
repowering
CBTLE-CCS
repoweriing
LEVELIZED ELECTRICITY GENERATION COST
vs GHG EMISSIONS PRICE
Generation Cost, $ per MWh e
140
120
Written-off PC-V plant
PC-CCS retrofit
CIGCC-CCS
NGCC-V
NGCC-CCS
CBTLE-CCS, $50/barrel crude
CBTLE-CCS, $75/barrel crude
CBTLE-CCS, $100/barrel crude
100
80
60
40
20
0
0
10 20 30 40 50 60 70 80 90 100
GHG emissions price,
$ per tonne of CO2eq
THOUGHT EXPERIMENT: DECARBONIZE 90% OF
EXISTING COAL POWER, 2020-2050 (9.4 GWe/y)
Key Attributes of Alternative Energy Futures
for US Coal Power in Carbon-Constrained World
3.0
2.5
2.0
Total CO2 stored in 2050, Gt CO2
Total GHG emissions avoided in 2050, Gt CO2eq
1.5
0.1 x (Total US coal use, EJ/y)
1.0
0.5
0.0
US coal use
2007, EJ/10
US coal use
2050 via
retrofits. EJ/10
US coal use
2050 via
repowering,
EJ/10
GHG
emissions
avoided 2050
via retrofits,
Gt CO2eq
GHG
CCS via
CCS via
emissions
retrofits 2050,
repowering
avoided 2050
Gt CO2
2050, Gt CO2
via
repowering, Gt
CO2eq
• 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, 2020-2050 (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, 2009-2010
• Core Group:
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–
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Robert Williams
Eric Larson
Tom Kreutz
LIU Guangjian
ZHENG Zhong
• China Collaborators
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–
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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