Synthetic fuel is the Bergius process. In this process, coal is liquefied by heating in the presence of hydrogen gas (hydrogenation). Dry coal is mixed with heavy oil recycled from the process. Catalysts are typically added to the mixture. The reaction occurs at between to and 20 to 70 MPa hydrogen pressure. The reaction can be summarized as follows: formula_1 After World War I several plants were built in Germany; these plants were extensively used during World War II to supply Germany with fuel and lubricants. The Kohleoel Process, developed in Germany by Ruhrkohle and VEBA, was used in the demonstration plant
Fossil fuel be found in hydrocarbon fields either alone, associated with oil, or in the form of methane clathrates. The theory that fossil fuels formed from the fossilized remains of dead plants by exposure to heat and pressure in the Earth's crust over millions of years was first introduced by Andreas Libavius “in his 1597 Alchemia [Alchymia]” and later by Mikhail Lomonosov “as early as 1757 and certainly by 1763”.. The first use of the term "fossil fuel" was by the German chemist Caspar Neumann, in English translation in 1759. The United States Energy Information Administration estimates that in 2007 the world's