using coal for and cli tcli mate change miti timiti...
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Using Coal for Energy Security d Cli t Ch Miti tiand Climate Change Mitigation
Eric D. Larson*Energy Systems Analysis Group
Princeton Environmental InstitutePrinceton University, USA
i t d / i/www.princeton.edu/pei/energy
Climate CentralPrinceton, NJ, USA
climatecentral orgwww.climatecentral.org
* Team effort with PEI Energy Group members Robert Team effort with PEI Energy Group members Robert Williams, Tom Kreutz, and Guangjian Liu.
PEI Energy Lunch Talk12 March 2010
U.S. Oil Use, Production and
Energy InformationAdministration, Annual Energy Review 2008, US Department of Energy, June 2009.
motor gasoline: 9 million B/D
Production, and Net Imports
66%
800,000 years of atmospheric CO2p 2concentrations
Global Climate Change Impacts in the United States, T.R. Karl, J.M. Mellilo, T.C. Peterson (editors in chief), Cambridge University Press, 2009.
Challenge of Climate Change Mitigation
• To stabilize climate (ΔT ≤ 2oC), 2050 GHG emissions must be: Business-as-usual emissions 62
GtCO2eq
GHG Emissions, Gt CO2 equivalent per year
60
70
– ½ of 2005 global emissions– Less than ¼ of projected “BAU” emissions globally.
2eq
40
50
– 80% reduction from 2005 emissions in industrialized countries
• IEA projects GHG emissions price 30
40
in 2030 in OECD:– $90/tCO2 550 ppmv stabilization– $180/tCO2 450 ppmv (~2oC ΔT)
Targeted emissions 14 GtCO2eq
10
20
$ / 2 pp ( )
Source: International Energy Agency, Energy Technology Perspectives, 2008
02005 2010 2015 2020 2025 2030 2035 2040 2045 2050
T i ib
Transportation Fuels• Transportation contributes significant GHG emissions, e g ~1/3 of US emissionse.g., 1/3 of US emissions.
• Liquid hydrocarbon fuels will b h d t l ibe hard to replace, e.g., air travel difficult without them.
• How to decarbonize hydrocarbon fuels?
• Biomass, the only carbon‐bearing renewable, may h i l l lhave essential role to play.
But Biomass is a Scarce Resource• “Food vs. Fuel” is a real issue
• Biomass for energy will likely gy ybe limited primarily to residues and material grown on poor quality lands.
• Must maximize benefits per unit biomass, e.g., crude oil displaced and GHG emissions avoidedemissions avoided.
Maximizing Biomass Benefits Using Coal
• Convert biomass to liquid fuels via “gasification”– Unlike biochemical processes, gasifiers can accept aUnlike biochemical processes, gasifiers can accept a wide range of biomass types: woody material, grassy material, even algae.
• Couple with CO2 capture and storage (CCS)– Converts biomass from “carbon‐neutral” to “carbon‐negative”; offers much more carbon mitigation benefitnegative ; offers much more carbon mitigation benefit than without CCS.
• Negative emissions from biomass enables some gcoal use while maintaining zero net CO2 emissions from the liquid fuels produced.
Gasification‐Based ConversionHigh-Value Products
Low valuefeedstocks Gas Cleanup
Oxygen
Gasification
Combined CyclePower Block
CO StSteam
Electricity
Gas & SteamTurbines
CO2 Storage
Coal CO, H2, H2S, H2O, CO2
FUELS
FischerTropsch
Catalytic Synthesis
H2S Removal
Clean
(H2 + CO)
Pet Coke
Oil Residue
BiomassWGS: CO + H2O
H2 + CO2
CO2 Removal
DME
SULFURRECOVERY Marketable
Byproducts
H2OWastes MeOH
MTG
MOGD
Sulfur
Slag
• All component technologies are commercial or in the case of• All component technologies are commercial or, in the case of biomass gasification and catalytic syngas cleanup, near‐commercial.
• CO2 removal is intrinsic part of liquid fuels production process.
Reasons for Optimism about CCS1. Natural analogues exist
– Oil and gas reservoirs– CO2 formations
2. Industrial analogues exist– CO2 EOR– Natural gas storageLi id t di l– Liquid waste disposal
3. Existing mega projects• Sleipner, Off‐shore Norway• Weyburn Canada
20 to 30 Mt/yr are injected for CO2-EOR in USA
• Weyburn, Canada• In Salah, Algeria
4. Fundamental physical and chemical processeschemical processes.
5. Numerical simulation of long term performance.
6 IPCC S i l R t (2005)6. IPCC Special Report (2005) large capacity, high confidence.
Source: Sally Benson, Stanford UniversityUnderground natural gas storage in USA
Coal/Biomass Co‐Processing Options H2S, CO2removal
PressurizedGasification
Gas cooling& cleaning
Air separation
oxygen
airUnderground
WaterGas Shift
CO2
CoalBiomass
SyngasConversion
SYNFUELS and/or
ELECTRICITY
H S COPressurized Gas cooling Water Sy ga
punit Underground
Storage
SYNFUELS H2S, CO2removal
PressurizedGasification
Gas cooling& cleaning
Air separation unit
oxygen
airUnderground Storage
WaterGas Shift
CO2
Coal SyngasConversion and/or
ELECTRICITY
Storage
Biomass PressurizedGasification
Gas cooling& cleaning
H2S, CO2removal
PressurizedGasification
Gas cooling& cleaning
WaterGas Shift
CoalBiomass
SyngasConversion
SYNFUELS and/or
ELECTRICITY
PressurizedCFBG
Air separation unit
oxygen
airUnderground Storage
CO2oxygen
Princeton System Designs• Detailed Aspen Plus simulations of energy/mass balances for
IGCC, FTL, MTG, and SNG.
• Aspen results provide the basis for capital cost estimates.
• Key technology components:Key technology components:
– GE‐type O2 slurry quench gasifier for coal
– GTI‐type O2 fluid‐bed gasifier + tar cracking for biomass2
– Rectisol® acid gas removal
– Slurry‐phase low‐temperature FT reactor with Fe catalyst
– Upgrading of crude FT to finished diesel and gasoline.
– MTG based on ExxonMobil process.
“F” l t bi f i l d– “F” class gas turbines for power island
Analysis details at: T.G. Kreutz, E.D. Larson, R.H. Williams, and G. Liu, “Fischer-Tropsch Fuels from Coal and Biomass,” 25th Annual International Pittsburgh Coal Conf, Pittsburgh, PA, 2008. (www.princeton.edu/pei/energy). See also: “Liquid Transportation Fuels from Coal and Biomass Technological Status, Costs, and Environmental Impacts,” U.S. National Academy of Sciences, May 2009.
d k l
Plant Design Parameters•Feedstocks: Coal vs. Biomass
‐ Coal‐to‐liquids: CTL – large scale (50,000 bbl/day)‐ Biomass‐to liquids: BTL – small scale (~4,400 bbl/day); limited by biomass supply logisticsbiomass supply logistics
‐ Coal + Biomass: CBTL – intermediate scale (~10,000 bbl/d) mixtures to meet environment and economic objectives
•Products: Fuels vs. Power‐ recycle (RC) plants – maximize fuel, minimize power- “Once through” (OT) designs – significant electricity co‐product
l‐ IGCC – power only
•Emissions: CO2 Venting vs. CCS‐ Upstream vs. downstream CO2 capture, different levels of capture
•Miscellaneous‐ Feedstock type (e.g. corn stover vs. switchgrass), gasifier type (e.g., GE vs. Shell for bituminous coal), synthesis reactor catalyst and configuration (e.g., for FT, Fe vs. Co and slurry‐bed vs. fixed‐bed)
CBTL, Once‐Through Synthesis + CCS
coal
HC
finished gasoline & diesel blendstocks
FT
Refinery H2 ProdGTCCPower net export
l t i it
flue gas
OxygenPlant
air
N2N2 to gas turbine
g y
oxygen steam
Gasification& Quench
Grinding & Slurry Prep
water
coal
SyngasScrubber
Acid GasRemoval
F-TRefining
F-TSynthesis
slag
syngasWater Gas
Shift
Recovery
unconverted syngas+ C1 - C4 FT gases
raw FT product
syn-crude
lightends
Island electricity
gascooling
expander
CO
2 Rem
oval
oxygenPlant
Saturator
2
FB Gasifier& Cyclone
Chopping & Lock hopperbiomass Tar
Cracking
CO2
CO2Flash
CO2
150 bar CO2to pipeline
dry ash
gascooling
FilterCO2 enriched methanol
Flash
Regenerator
H2S + CO2To Claus/SCOT
fuel gases topower island
purge gasesrecyclegases
methanolmethanol RefrigerationPlant
C5/C6Isomerization
HC
Recovery
raw FT product
DistillateHydrotreating
NaphthaHydrotreating
Gasoline Pool
isomerate gasolineblendstock
pg
CatalyticReforming
reformate
H
H2
H2
WaxHydrocracking
Diesel Pool
dieselblendstock177oC + hydrocarbons
H2
H2
H2
gasesliquids
Net Lifecycle GHG Emissions for Fuels f Bi d/ C lfrom Biomass and/or Coal
Coal‐FTLCoal‐gasoline (MTG)
Coal‐FTL w/CCSCoal‐MTG w/CCS
h lCurrent EthanolEthanol
Coal/bio‐MTG w/CCSCoal/bio‐FTL w/CCS
Bio‐FTLBio‐MTG
Ethanol w/CCSBio‐FTL w/CCS
Bio‐MTG w/CCS
GHG Emissions Relative to Emissions from Crude Oil Products DisplacedGHG Emissions Relative to Emissions from Crude Oil Products Displaced
Electricity co-product assigned GHG emissions for IGCC-CCS (90% CO2 capture) = 138 kg CO2eq/MWh (lifecycle).
Biomass Needed to Make Zero GHG Fuels4.0
3.0
3.5
uel (
LHV) Coal
Biomass
2.0
2.5
GJ
liqui
d fu
1.0
1.5
mas
s pe
r G
0.0
0.5
GJ
bio
Co-processing for FTL, MTG• One liter of fuel from biomass, whether made via thermochemical or via biochemical processing, requires about same amount of biomass feedstock.
• Co‐processing biomass with coal to make a liter of zero‐GHG liquid fuels requires half or less as much biomass as a “pure” biofuel.
Compared to what?
160
180
200,
Historical DataHigh Price CaseReference CaseRevised Rerference Case
120
140
160
Oil
Pric
epe
r Ba
rrel Revised Rerference Case
Low Price Case
80
100
ted
Crud
e 7
Dol
lars
p
> $100/bbl by 2012‐2015
20
40
60
Impo
rt$2
007 $ / y
0
20
2005 2010 2015 2020 2025 2030
Low Price, Reference Case, and High Price projections from the U.S. Department of Energy, Energy Information Administration, Annual Energy Outlook 2009 (March 2009). Subsequently (April 2009) EIA revised Reference Case projection to reflect expectation that world recession would last longer than expected in AEO 2009.
Year
Breakeven Fuel Production Costswith Zero GHG Emissions Pricewith Zero GHG Emissions Price
140
160
valent 2007 US$/bbl
100
120
line Eq
ui
60
80
l of G
aso
oil
l oil
20
40
Per Ba
rrel
$60/bb
l
$100/bbl
0$ P
Gasoline CTL CTL‐CCS CBTL CBTL‐CCS EtOH BTL BTL‐CCS
$ / $ /
Source: Liquid Transportation Fuels from Coal and Biomass Technological Status, Costs, and Environmental Impacts, U.S. National Academy of Sciences, May 2009.
Coal price = $1.7/GJHHV ‐‐‐‐‐‐ Biomass price = $5/GJHHV
Larson et al Energy and
Delivered Feedstock Costs (2007$)Corn Mixed PrairieLarson, et al., Energy and
Environmental Science, January 2010
Corn stover
Mixed PrairieGrasses
Coal
$/dry t 66 134 39 (as rec’d)
$/GJHHV 3.8 7.2 1.44
Coal‐CCS MPG‐CCS CB‐OT‐CCS
Coal (mt/d) 24,297 0 6,689
$/GJHHV 3.8 7.2 1.44
Coal (mt/d) 24,297 0 6,689
Biomass (dry mt/d) 0 3,581 3,581
Liquids, bbl/day 50,000 4,415 13,039
N l i i MW 317 24 406Net electricity, MW 317 24 406
Total Efficiency (HHV) 49% 49% 47%
LC GHGs of liquid fuel* 1 x oil ‐3 x oil ‐0.1 x oil
Capex ($/bpd) 98,900 146,700 149,092
Capex (billion $) 4.9 0.65 1.9
Liquid cost $/gal ge** 1 6 3 9 2 2Liquid cost, $/gal ge 1.6 3.9 2.2
Breakeven oil $/bbl 59 167 88* Electricity charged with emissions of IGCC‐CCS (138 kgCO2/MWh)** With electricity sold for $60/MWh, which was average US grid wholesale price in 2007.
Cost of Liquid Fuel vs. GHG Emission Price
Coal‐CCS
MPG‐CCS
(C+S)‐OT‐CCS
Larson, et al., Energy and Environmental Science, January 2010
What potential to impact U.S. energy it d GHG i i ?security and GHG emissions?
• Two estimates of future biomass availability:yA) 1.3 billion tons/yr (“Billion ton study,” 2005)
B) 0.55 billion tons/yr (“America’s Energy Future study,” 2009)
• If all biomass used in CBTL‐CCS systems designed to maximize liquids output, it would produce:A) 14 x 106 bpdequiv.; avoiding ~24% of 2007 U.S. CO2 emissionsq
B) 5.9 x 106 bpdequiv.; avoiding ~10% of 2007 U.S. CO2 emissions
U.S. oil use in 2008: 19.4 x 106 bpd, of which 9 x 106 was gasoline and about 13 x 106 was imported.
Global impact?• Global estimates for mid‐century biomass availability for energy (including with dedicated energy crops on cropland):– 441 EJ/yr (Moomaw et al., 2001)
– 206 EJ/yr (Berndes et al., 2003)
• Estimate for 2050 excluding use of good cropland:stimate for 050 excluding use of good cropland:– 106 EJ/yr (~USA total primary energy use today).
[75 EJ/yr residues (IEA, 2008) + 31 EJ/yr from use of abandonded agricultural lands (based on Campbell et al, 2008)]
Moomaw WR, Moreira JR, Blok K, Greene DL, Gregory K, et al., 2001: “Technological and economic potential of greenhouse gas emissions reduction,” in Climate Change 2001: Mitigation; Contribution of Working Group III to the Third Assessment Report of the IPCC, ed. B Metz, O Davidson, R Swart, J Pan, pp. 171–299. Cambridge, UK: Cambridge Univ. Press.
B d G H ijk M V D B k R 2003 “Th t ib ti f bi i th f t l b l l i f 17 t di ” Bi d BiBerndes G, Hoogwijk M, Van Den Broek R., 2003: “The contribution of biomass in the future global energy supply: a review of 17 studies,” Biomass and Bioenergy 25:1–28.
Campbell, J.E., D.B. Lobell, R.C. Genoa, and C.B. Field, 2008: “The global potential of bioenergy on abandoned agricultural lands,” Environmental Science and Technology. (429 million hectares @ average 4.3 dry t/ha/yr biomass production)
IEA (International Energy Agency), 2008: Energy Technology Perspectives 2008: Scenarios and Strategies to 2050, Paris, France.
Global Thought Experiment
160180200
Marine
2 & 3 wheelersminibuses
buses
TRANSPORTATION FUEL DEMANDS
LIQUIDS S
BIOMASSQ
100120140160
r yea
r Energy crops on degraded lands
BTL‐CCS
Air
Medium trucks
Marine SUPPLIES REQUIRED
6080
100
EJ p
er
BTL CCS
CBTL‐CCS
GHG
Heavy trucks Net
Zero GHGs
02040
GHGs offsetLight
dutyvehicles
Crude oil products
0
S t i bl M bilit
20502005 2050SMP modified
(LDVs: 3.1 liters/100 km, 76 mpg)
(LDVs: 10.4 liters/100 km, 23 mpg)2050
SMP modified
Sustainable MobilityProject (SMP) scenario(LDVs: 8.6 liters/100 km, 27.5 mpg)
Source: Robert Williams, Princeton University
Prius in 2030 (MIT study)
Summing Up• CBTL‐CCS appears to be an attractive way to maximize benefits from biomass for both energy security and GHG mitigation
• C‐negative biomass offsets C‐positive coal, resulting in more low‐GHG liquid fuel production
both energy security and GHG mitigation.
per ton of biomass than for a pure biofuel. • Capital‐cost scale economies of coal conversion, low cost of coal (despite high costs for biomass)low cost of coal (despite high costs for biomass), and electricity co‐product sales all help system economics.
• Costs for CO2 capture are low – good option for demonstration projects needed to gain
fid i CCSconfidence in CCS.• Except for CCS, technologies are all commercial.
Hurdles to a CBTL‐CCS Industry?
• Lack of confidence/demonstration of CCS at scale.
• Carbon emissions value not high enough to induce CCS as• Carbon emissions value not high enough to induce CCS as commercial activity.
• Optimum economics favor cross‐industry alliances that• Optimum economics favor cross industry alliances that have little historical precedent, e.g., collaboration of coal, ag, oil, and power industries.
• High cost of first few plants requires government incentives (which can be justified based on future public benefits), but unclear if incentives in current legislation are applicable.
• Some strongly object to continued coal use, especially for li id f l i i i “b i d i h”liquid fuels: mining impacts, “bait and switch”,....