Bergius process

The Bergius Process is a method of production of liquid hydrocarbons for use as synthetic fuel by hydrogenation of lignite (brown coal) at high temperature and pressure. It was first developed by Friedrich Bergius in 1913.

The Process
Lignite or sub-bituminous coal is finely ground and mixed with heavy oil recycled from the process. Catalyst is typically added to the mixture. A number of catalysts have been developed over the years, including tungsten or molybdenum sulfides, tin or nickel oleate, and others.

The mixture is pumped into a reactor. The reaction occurs at between 400 to 500 °C and 20 to 70 MPa hydrogen pressure. The reaction produces heavy oils, middle oils, gasoline, and gases. The overall reaction can be summarized as follows:

$$n{\rm C} + (n+1){\rm H}_2 \rarr {\rm C}_n{\rm H}_{2n+2}$$

The different fractions can be passed to further processing (cracking, reforming) to output synthetic fuel of desirable quality. Overall, 97% of input carbon can be converted into synthetic fuel. The hydrogen required for the process can be also produced from coal by steam reforming.

Usage


Bergius process was used for production of synthetic gasoline in Germany during World War II (e.g., Hydrierwerke Pölitz, Police, Poland).

One variation of the Bergius process is currently used by company Sasol in South Africa.