The Fischer-Tropsch process converts a mixture of hydrogen and carbon monoxide, called syngas, into liquid hydrocarbon fuels and lubricants. Coal, natural gas or biomass can be a source for syngas. It is produced by means of gasification, where the source material is chemically treated with oxygen or water vapor at high temperature and pressure. Syngas is reacted under variable heat in the presence of a catalyst, usually cobalt, iron, or ruthenium, to produce the synthetic petroleum. German researchers Franz Fischer and Hans Tropsch developed the process in the 1920's.
Syngas as a liquid fuel source has attracted considerable interest from nations with little petroleum but an abundance of the raw material needed to produce the gas. Biomass to liquid is a particularly attractive alternative, being a renewable resource. The Fischer-Tropsch process converts syngas into liquid hydrocarbons, carbon dioxide and water. Variable grades of synthetic petroleum can be produced depending on temperature, pressure and catalyst used in the process. At 625°F (330°C) synthetic gasoline is produced, while at 390°F (200°C) the product would be a synthetic diesel fuel, for example.
The gasification process is a very energy intensive undertaking. Although the source material may be plentiful and inexpensive, high manufacturing costs typically make syngas an uneconomical alternative. Implementing a Fischer-Tropsch process facility also requires a large capital investment in equipment and is subject to high operating costs. Further refinement in the efficiency of the process or a considerable rise in the price of natural petroleum would likely be necessary for its widespread adoption for future energy development.
Despite its drawbacks, the Fischer-Tropsch process has been successfully used in both demonstration and regular production facilities. In the 1930's, the process was used in Germany to produce synthetic liquid fuel from the coal abundant in the region. Continuing improvement in the process has led to several variants with most implementations employing a proprietary technology.
South African Coal and Oil (SASOL) has produced liquid fuels from coal by the Fischer-Tropsch process since the 1950's. The company has contracted for two modern plants in China; each is capable of producing 80,000 barrels of synthetic petroleum a day. Several major oil companies have experimented with synthetic production in small-scale demonstration facilities. The largest consumer of fuel in the world, the U.S. military, continues to sponsor research in the Fischer-Tropsch process. In this case, the goal is a fuel source entirely under domestic control, rather than economic or environmental concerns.
