Comparative analysis of the production costs and life-cycle GHG emissions of FT liquid fuels from coal and natural gas.

Liquid transportation fuels derived from coal and natural gas could helpthe United States reduce its dependence on petroleum. The fuels could be produced domestically or imported from fossil fuel-rich countries. The goal of this paper is to determine the life-cycle GHG emissions of coal- and natural gas-based Fischer-Tropsch (FT) liquids, as well as to compare production costs. The results show that the use of coal- or natural gas-based FT liquids will likely lead to significant increases in greenhouse gas (GHG) emissions compared to petroleum-based fuels. In a best-case scenario, coal- or natural gas-based FT-liquids have emissions only comparable to petroleum-based fuels. In addition, the economic advantages of gas-to-liquid (GTL) fuels are not obvious: there is a narrow range of petroleum and natural gas prices at which GTL fuels would be competitive with petroleum-based fuels. CTLfuels are generally cheaper than petroleum-based fuels. However, recent reports suggest there is uncertainty about the availability of economically viable coal resources in the United States. If the U.S. has a goal of increasing its energy security, and at the same time significantly reducing its GHG emissions, neither CTL nor GTL consumption seem a reasonable path to follow.