Direct liquefaction of lowerrank coals and biocoals ... ScienceDirect
Introduction. Direct coal liquefaction (DCL), invented by Friedrich Bergius in 1913 [1], encompasses the catalytic conversion of coal by hydrogen and high temperatures in presence of a solvent and was used to produce transportation fuels on a commercial scale in the first half of the past century especially in Germany and Great Britain [2], [3], [4].