The Fischer-Tropsch process is a catalyzed  reaction in which a chemical synthesis gas, and a mixture of carbon monoxide and hydrogen, is transformed into liquid hydrocarbons of different forms. The most common catalyst is  based on iron and cobalt, but  nickel and ruthenium have been used. The main purpose of this process is to create a synthetic petroleum substitute, usually from coal, or natural gas or bio-mass, for uses in synthetic lubrication oil or synthetic fuel. This fuel runs trucks, cars, and some aircraft engines.