Coal can also be converted into liquid fuels like gasoline or diesel by several different processes.
The Fischer-Tropsch process of indirect synthesis of liquid hydrocarbons was used in Nazi Germany for many years and is today used by Sasol in South Africa.
Coal would be gasified to make syngas (a balanced purified mixture of CO and H2 gas) and the syngas can be condensed using Fischer-Tropsch catalysts to make light hydrocarbons which are further processed into gasoline and diesel.
A direct liquefaction process, Sergius process (liquefaction by hydrogenation), is also available but has not been used outside Germany, where such processes were operated both during World War I and World War II.
SASOL in South Africa has experimented with direct hydrogenation.
Several other direct liquefaction processes have been developed, among these being the SRC-I and SRC-II (Solvent Refined Coal) processes developed by Gulf Oil and implemented as pilot plants in the United States in the 1960s and 1970s.
Another direct hydrogenation process was explored by the NUS Corporation in 1976 and patented by Wilburn C. Schroeder.
The process involved dried, pulverized coal mixed with roughly 1% molybdenum catalysis.
Hydrogenation occurred by use of high temperature and pressure synthesis gas produced in a separate gasifier.
The process ultimately yielded a synthetic crude product, naphtha, a limited amount of C3/C4 gas, light-medium weight liquids (C5~C10) suitable for use as fuels, small amounts of NH3 and significant amounts of CO2.
Yet another process (Karrick process) to manufacture liquid hydrocarbons from coal is low temperature carbonization (LTC), which was developed by Lewis C. Karrick, an oil shale technologist at the U.S. Bureau of Mines in the 1920s.
由煤生产液态烃的另一种工艺（Karrick工艺）是低温碳化（LTC），它是由1920年美国矿业局的油页岩技术专家Lewis C. Karrick开发的。
Coal is coked at temperatures between 450°C and 700°C compared to 800°C to l ,000°C for metallurgical coke.
These temperatures optimize the production of coal tars richer in lighter hydrocarbons than normal coal tar. The coal tar is then further processed into fuels.