TransForum Vol. 8, No. 2

Version 1.8b of GREET Now Available

The newest version of the GREET (Greenhouse gases, Regulated Emissions and Energy use in Transportation) model is now available from Argonne.

GREET allows researchers and analysts to evaluate energy and emission effects of various vehicle and fuel combinations so that the complete fuel cycle from wells to wheels and the vehicle cycle through material recovery and vehicle disposal can be considered. GREET is a multidimensional spreadsheet model in Microsoft Excel with a graphic user interface program designed in Visual Basic.

Researcher Michael Wang and his team regularly update key parameters and assumptions in the GREET model and expand the model on the basis of new research and development in fuel pathways and vehicle technologies. Today, GREET can simulate more than 100 fuel production pathways and more than 82 vehicle/fuel systems. The model has more than 9,000 registered users worldwide.

What’s New in GREET 1.8b?

New fuel production pathways:

• Brazilian sugarcane ethanol,
• Corn to butanol,
• Soybeans to renewable diesel via hydrogenation,
• Coal/biomass co-feeding for Fitscher-Tropsch diesel production,
• Various corn ethanol plant types with different process fuels, and
  Pet coke to hydrogen production.

Enhancements of existing pathways:

• Inclusion of three methods in dealing with co-products for soybean-based biodiesel;
• Compression energy efficiencies for natural gas and hydrogen are calculated with the first law of thermodynamics;
• Tube trailer delivery option for gaseous hydrogen to refueling stations;
• Revision of petroleum refining energy efficiencies based on recent Energy Information Administration’s survey data;
• Updated petroleum refinery processes to include hydrogen from different feedstock sources; and
• Updated corn farming energy use.

GREET is available as a FREE download at www.transportation.anl.gov/modeling_simulation/GREET/.

Funding for the development and maintenance of the GREET project was provided by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy through the Vehicle Technologies Program, the Biomass Program and the Hydrogen Program.

November 2008