FischerTropschsyntes

Fischer–Tropsch synthesis is a family of chemical reactions that converts synthesis gas, a mixture of carbon monoxide and hydrogen, into liquid hydrocarbons. The process is catalyzed by transition metals, most commonly cobalt or iron, supported on oxides or other carriers. Nickel and ruthenium can also be used in some variants. The synthesis gas is typically produced from coal, natural gas, or biomass, and the operating conditions vary with the catalyst and desired products.

Two main process regimes are recognized: low-temperature Fischer–Tropsch synthesis (LTFT) and high-temperature Fischer–Tropsch synthesis (HTFT). LTFT generally operates at about 150–250 °C and higher pressures, using cobalt or iron catalysts to favor longer chain hydrocarbons suitable for fuels in the diesel or wax range. HTFT operates at roughly 250–350 °C and can use iron or cobalt catalysts, producing a broader mix of hydrocarbons including gasoline-range products. The overall stoichiometry can be summarized as a combination of CO and H2 forming hydrocarbons and water, with the chain growth described statistically by the Anderson–Schulz–Flory distribution.

Products and applications vary from light gases to long-chain paraffins and olefins. In practice, the process is used to produce synthetic fuels and chemical feedstocks in gas-to-liquids (GTL), coal-to-liquids (CTL), and biomass-to-liquids (BTL) projects. Industrial deployment includes large-scale GTL plants that convert stranded natural gas into liquids. The technology offers a route to liquid fuels independent of crude oil, albeit with significant energy input and considerations regarding feedstock sources and lifecycle emissions.