GTL Fuel, which Audi has been using to power their R10 Le Mans winning race car for over three years is a synthetic fuel made from natural gas through a chemical reaction, has reduced CO2 emissions of about 13% from conventional fuel and is free of sulphur. Equally important to the environmental and U.S. domestic economic benefits of such a fuel is that GTL unlike compressed natural gas can be used immediately in all vehicles fitted with a TDI engine without requiring any retrofitting.
Through a technical partnership with Shell, Audi developed the first ever diesel-racing car to win Le Mans 24 in 2006 and repeated in 2007 and 2008. The diesel used in the TDI powered R10 is a race grade version of GTL fuel. GTL conversion is an umbrella term for a group of technologies that can create liquid synthetic fuels from a variety of sources. The basic technology, developed in Germany in the 1920s, uses catalytic reactions to synthesise complex hydrocarbons from simpler organic chemicals. This process can create identical liquids from a variety of means, although the technical challenges are greater for biomass and coal. There are two main categories of natural gas-based technology of this kind; high and low temperature versions. The high-temperature, iron catalyst-based Fischer-Tropsch GTL process produces fuels such as gasoline and gasoil that are closer to those produced from conventional crude oil refining, free of sulphur but with aromatics. The low-temperature, cobalt catalyst-based Fischer-Tropsch GTL process, however, produces an extremely clean synthetic fraction of gasoil called GTL Fuel that is virtually free of sulphur and aromatics.
While there are lots of positive developments with alternative fuels and vehicles, even compressed natural gas, GTL is immediately compatible with existing diesel engines and the current distribution infrastructure that many automakers including Honda claim is prohibitive to their production ready hydrogen and natural gas vehicles. Shell has operated a medium scale GTL plant at Bintulu, Malaysia since 1993, that has current capacity of 14,700 bbl/day. With a decade of operating experience at the Bintulu plant, Shell is planning to increase total production of up to 140,000 bbl/day once a new and larger GTL plant being built in Qatar towards the end of the decade is built.