For countries in remote areas with large reserves of natural gas, e.g. the State of Qatar, the economic utilization of this gas is in our opinion only possible in a low-cost process that converts the natural gas to liquid hydrocarbons. The basic concept of low-cost process was presented in the first of a series of four papers: in a first step a nitrogen-rich synthesis gas is produced by catalytic partial oxidation of natural gas with air (for details see the second paper). The syngas is then converted by Fischer-Tropsch-synthesis to higher hydrocarbons. In the following and third paper the results of kinetic studies on Fischer-Tropsch-synthesis are discussed. The experiments were carried out by using an alkalized precipitated iron catalyst in a bench-scale reactor at pressures up to 30 bar and temperatures ranging from 200-300°C