SURVEY OF METHODS OF COAL HYDROGENATION FOR THE PRODUCTION OF LIQUIDS

More than 60 coal hydrogenation-liquefaction processes are reviewed with respect to various process variables. These variables include temperature, pressure, residence time, catalyst type and percent, raw materials, liquid to coal ratio in the feed, percent product yield, space rate utilization, plant capacity, and references. The bibliography includes over 100 references covering the years 1910 to 1978. This reference section will help the reader to find additional information about an individual process. With most coal hydrogenation-liquefaction processes coal will have a residence time of about one hour in the reactor. This is especially true when these systems involve the reaction of coal mixed with a vehicle oil. However, those processes which involve the reaction of dry coal with hydrogen have reported residence times of a fraction of a second to several minutes. It is also apparent that those processes involving higher temperatures also have a higher gaseous yield. This is true even when the coal residence time is greatly shortened. In the past few years improvements have been made with catalysts. The improved catalysts have helped to decrease the necessary pressure of processes. © 1979.