The Fischer-Tropsch synthesis enables the conversion of syngas (typically CO and H₂) into a crude oil-like product mixture. In contrast to methane or methanol synthesis, no single target molecule is synthesized, but rather hydrocarbons of varying structure and chain length are produced. A distinction is made between high-temperature Fischer-Tropsch synthesis (HTFT, 300–350°C), which primarily produces short-chain hydrocarbons (gasoline), and low-temperature Fischer-Tropsch synthesis (LTFT, 200–250°C), which primarily produces long-chain hydrocarbons (kerosene, diesel, waxes). The former allows, in part, the direct conversion of CO₂ and H₂, while the latter requires prior reduction of CO₂ to CO. The reaction is highly exothermic (i.e., heat is released during the reaction) and occurs at elevated pressures between 20 and 100 bar. Iron (Fe) or cobalt (Co) catalysts are predominantly used.

The synthesis product must then undergo hydrotreatment with hydrogen and be subsequently separated into different product fractions (fractionation).

The Fischer-Tropsch synthesis can be used for synthesis-based and thus power-based fuel production as well as for specialty waxes. Particularly in terms of fuel and chemical feedstock production, this synthesis pathway provides a production route independent of crude oil. Additionally, this synthesis-based fuel production offers extended possibilities for producing optimized fuel blends compared to crude oil-based fuels, especially regarding their use in engines or turbines.

For an overview of various Power-to-Liquid processes, please refer to the following link:
Dietrich, V, Buttler, A., Hanel. A, Spliethoff, H. Fendt, S. (2020), Power-to-liquid via synthesis of methanol, DME or Fischer–Tropsch-fuels: a review. In: Energy & Environmental Science, Ausgabe 13, S. 3207-3252