Hydrocracking is a refining technology within the scope of hydroprocessing that is used for the conversion of a variety of feedstocks to a range of products by adding hydrogen, removing impurities in the presence of a catalyst. Hydrocracking technology for conversion of coal to liquid fuels was developed in Germany as early as 1915. The forerunner of hydrocracking was the Bergius process, which may be considered as the first commercial plant and brought on stream in Germany in 1927 for hydrogenation of distillates-derived brown coal. Hydrotreating and hydrocracking employ process flow schemes and similar catalysts where hydrocrackers tend to operate at more severe operational conditions as hydrotreaters are not conversion units through which breaking of carbon to carbon bonds is minimal. The hydrocracking process, which converts heavy feedstock to lower-molecular-weight, high-value products, is the result of combining catalytic cracking reactions with hydrogenation, and removes heteroatoms and saturates olefins and aromatics according to the complex reaction patterns.