ABSTRACT
Hydrocracking is one of the oldest hydrocarbon conversion processes. An extensive hydrocracking technology for coal conversion was developed in Germany between 1915 and 1945 in order to secure a supply of liquid fuels derived from domestic deposits of coal [l]. The first Bergius plant for hydrogenation of brown coal, put on stream in Leuna, Germany in 1927, applied what may be considered the first commercial hydrocracking process. Similar though less extensive efforts to convert coal to liquid fuels took place in Great Britain, France, and several other countries. Conversion of coal to liquid fuels was a catalytic process, operating at high pressures (200-700 atm) and high temperatures (375-525°C). Between 1925 and 1930, I. G. Farbenindustrie in Germany, in collaboration with Standard Oil of New Jersey, developed a hydrocracking technology designed to convert heavy gas oils to lighter fuels [2]. Attempts were also made in the United States to develop a hydrocracking technology capable of upgrading heavier petroleum fractions [3]. Such hydrocracking processes required high pressures (200-300 atm) and high temperatures (over 375°C). Among the earliest hydrocracking catalysts, pelleted tungsten sulfide was the most successful [4]. Other hydrocracking catalysts used before and during World War II were iron or nickel supported on fluorinated montmorillonite [5] and nickel supported on amorphous silicaalumina [6].
