The Air Force has been testing synfuels such as the Renjet(TM) synthetic jet fuel manufactured by Rentech, Inc. using a gasification and Rentech (TM) Fischer-Tropsch process. It was mandated by law EISA Section 526 that Federal agencies including the Department of Defense cannot purchase alternative synfuels unless the alternative fuels have lower GHG emissions than refined petroleum based fuels. Many organizations that oppose any use of coal applauded this law, because they thought it would be end of coal-to-liquids jet and diesel fuel for the U.S. Air Force.

The NETL conducted a comprehensive study of the GHG emissions for refined petroleum based fuels that considered the well-to-wheels life cycle of liquid fuel from crude feedstock from different sources. It evaluated on a well-to-wheels basis the three green house gases that are the result of petroleum processing: CO2, methane and nitrous oxide.

The NETL study demonstrates that the source of the crude feedstock is a significant factor for determining the quantity the wells-to-wheels GHG emissions. The data shows that when the sources of the feedstocks are taken into consideration, the GHG emissions vary significantly. Broad statements about GHG emissions from all refined fuels should not be made based on the characteristics for domestic crude oil such West Texas Intermediate.

The NETL study shows that coal-to-liquid fuel has lower GHG emissions than refined fuels that use feedstock from many foreign sources. The sources that contribute the most GHG emissions are Nigeria, Venezuela and the syncrude from the Canadian tar sands. Fuels from these sources of feedstock actually exceed the standards legislated by Section 526 and would not meet the test to be approved for purchase by the U.S. Air Force.

When the source of the feedstock is considered, coal-to-liquid fuels have a lower GHG emission profile. The GHG emissions for coal-to-liquid fuels is 5% to 12% lower than petroleum based fuels processed from many sources of import feedstocks.Liquid fuels derived from crude oil imported from Mexico, Venezuela, Angola and Canadian tar sands generate much more GHG emissions on a well-to-wheels basis than liquid fuel derived from coal gasification.