Argonne National Laboratory Transportation Technology R&D Center Transportation Fuel-Cycle Analysis: What Can the GREET Model Do? Michael Wang Center for

Argonne National LaboratoryTransportation Technology R&D Center

Transportation Fuel-Cycle Analysis:What Can the GREET Model Do?

Michael Wang

Center for Transportation Research

Argonne National Laboratory

U.S. EPA Fuel-Cycle Modeling Workshop

Louisville, KY, May 26, 1999


Fuel-Cycle Analysis Becomes Necessary When Comparing Different Fuels

• Up-stream emissions vary considerably among different fuels

• As tailpipe emissions will be tightened for future vehicles, up-stream emissions will become a major source

0

200

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600

GH

Gs

: g

/mi

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EtO

H F

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CN

GV

EtO

H F

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EV

Feedstock Fuel Vehicle

Tier 1 Tier 2

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0.6

Urb

an

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g/m

i

GV

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EtO

H F

FV

EV

GV

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GV

EtO

H F

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Feedstock Fuel Vehicle

Tier 1 Tier 2


GREET Estimates Per-Mile Energy Use and Emissions Rates

• Emissions of greenhouse gases (weighed together with GWPs):

– CO2, CH4, and N2O

– VOC, CO, and NOx as optional GHGs

• Energy use:

– All energy sources

– Fossil fuels

– Petroleum

• Emissions of five criteria pollutants (total and urban separately):

– VOC, CO, NOx, PM10, and SOx


GREET1.4a Includes Over 30 Fuel Cycle Pathways

PetroleumConv. & Reform. Gasoline

Conv. & Reform. Diesel

LPG

CNG

LNG

Dimethyl Ether

Methanol

Fischer-Tropsch Diesel

Natural Gas

Hydrogen

Ethanol

Biodiesel

Corn

Biomass

Soybean

Solar Energy

Various Sources Electricity

Flared Gas

Landfill Gas


GREET1.4a Includes Over 50 Near- and Long-Term Vehicle Technologies

Conv. SI Vehicles• CG, RFG• CNG: dual-fuel, dedicated• LNG, LPG• MeOH, EtOH: FFVs, dedicated

SIDI Vehicles• RFG• CNG: dedicated• LNG, LPG• MeOH, EtOH: dedicated

CIDI Vehicles• CD and RFD• DME• FTD• Biodiesel

Other Vehicles• Battery-powered EVs• HEVs: CIDI and SIDI engines

– grid independent– grid connected

• FCVs: H2, gasoline, MeOH, EtOH


GREET, Mobile5, and Part5:GREET Uses Outputs from Both Models

• Vehicular emissions of baseline gasoline and diesel vehicles:

– HC, CO, NOx, and CH4 from Mobile5

– PM10 from Part5

• AFV emission changes are estimated with their emission testing results and technology potentials– SI AFV emissions relative to gasoline vehicles – CI AFV emissions relative to diesel vehicles

• SOx emissions are calculated from sulfur content of fuels

• CO2 emissions are estimated from carbon balance

• N2O emissions are assumed with emission testing results and technology potentials


DOE/OTT Has Been a Major Sponsor of GREET Development

• GREET sponsors include:– OTT’s Planning and Assessments (P. Patterson)– OTT’s Office of Technology Utilization (D. Rodgers)– State of Illinois (DCCA, D. Loos)

• GREET1.4a status:– Draft report was completed last fall and comments were

received last winter.– Final report and model will be completed in this summer

• GREET1.0 report and GREET1.4 model is available at

www.transportation.anl.gov/ttrdc/publications/


GREET Applications for Evaluations of Individual Industries

• Corn-based ethanol– A study was conducted for the state of Illinois in 1997– A follow-up study was completed in 01/99 for DOE

(report available from the AFV Hotline)• Natural gas-based fuels

– Draft report now under review– Final report to be out in 07/99

• EPRI is to recommend an EV-friendly GREET version to electric utility companies


Per-Mile GHG Emissions Reductions by Ethanol Blends (Relative to Gasoline)

0%

20%

40%

60%

80%

100%

120%

E10

E85

E95

E10

E85

E95

E10

E85

E95

E10

E85

E95

E10

E85

E95

E10

E85

E95

E10

E85

E95

E10

E85

E95

Dry, current

Dry, near future

Wet, current

Wet, near future

W. biomass, near future

H. biomass, near future

W. biomass, future

H. biomass, future


Per-Mile GHG Emission Changes: Near-Term Cars (Relative to Tier 1 GVs)

-80% -60% -40% -20% 0% 20%

FRFG2

CARFG2

Conv. CI: CD

CIDI: CD

CNG: bi-fuel

CNG: dedicated

MeOH FFV: M85

LPG: converted, NG

LPG: converted, crude

EtOH FFV, E85, corn

E10, corn

EV: U.S. mix

EV: CA mix

EV: U.S. NE mix

Grid C. HEV: FRFG2, US mix

Grid C. HEV: CARFG2, CA mixGrid I. HEV: FRFG2

Grid I. HEV: CD

Per-Mile GHG Emission Change


Per-Mile GHG Emission Changes: Long-Term Cars (Relative to Tier 2 GVs)

-140% -120% -100% -80% -60% -40% -20% 0%

Per-Mile GHG Emission Change


On-Going GREET Development Efforts

• Add air toxic emissions into GREET

• Revise key assumptions regarding up-stream fuel

production activities and vehicle operations

• Include additional fuel-cycle pathways and vehicle

technologies, as appropriate

• Explore ways to address uncertainties in GREET

simulations


Efforts Are Required to Make GREET a Facility-Specific Model

• Industry-average data in the current GREET version need to be revised to facility-specific data

• Pathway boundary for a simulated facility need to be defined• Clear guidance on using industry-average vs. facility-

specific data is needed• A mechanism needs to be in place for fuel producers to

predict emissions of future facilities• Vehicular fuel economy and emissions may not be ignored

completely

Documents

Argonne National Laboratory Transportation Technology R&D Center Transportation Fuel-Cycle Analysis: What Can the GREET Model Do? Michael Wang Center for