Coal Conversion Processes, Liquefaction

Abstract Coal liquefaction involves taking the solid coal to liquid hydrocarbon and oxygenate products. Both direct and indirect routes, the latter being known as the Fischer‐Tropsch process, are known. Direct liquefaction utilizes hydrogenation (hydroliquefaction) or pyrolysis of the coal in a single processing sequence. Indirect liquefaction processes involve the production of synthesis gas, ie, coal gasification, as the first step, followed by catalytic conversion to liquid products. Liquefaction processes that have moved beyond the laboratory are discussed. Flow diagrams, reactor types and conditions, catalytic composition, conversion efficiency, and product make‐up are given.