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.

CBTL‐CCS Carbon Flows(~40:60 bio:coal input  zero net GHG fuel)

Released carbon

Stored carbon

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.

How much is this going to cost?How much is this going to cost?

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

Illinois Minemouth CBTL Case Study

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”,....

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