ZWEISTUFIGES KATALYTISCHES KOHLEHYDRIERUNGSVERFAHREN UNTER EXTINKTIONSRUECKFUEHRUNG VON FRAKTIONEN SCHWERER FLUESSIGKEIT

摘要

In a process for catalytic two-stage hydrogenation and liquefaction of coal a recycled heavy liquid fraction 15 boiling above a distillation cut point of about 600-750 DEG F (316-399 DEG C) is mixed at 14 with coal 10. The resultant slurry and hydrogen from 17 are fed into a first stage catalytic reaction zone 20 operated at conditions which promote controlled rate liquefaction of the coal. The first stage reactor 20, is maintained at 700-800 DEG F (371-427 DEG C) temperature, 1000-4000 psig (6.9-27.6 MPa) hydrogen partial pressure, and 10-90 1b/hr per ft<3> catalyst (160-1442 kg/h/m<3>) space velocity. Partially hydrogenated material withdrawn from the first stage reaction zone 20 is passed directly to the second stage catalytic reaction zone 30 maintained at 760-860 DEG F (404-460 DEG C) temperature for further hydrogenation and hydroconversion reactions. The 600-750 DEG F (416-399 DEG C) fraction 15 contains 0-20 W % unreacted coal and ash solids. If desired, fraction 68 can be catalytically hydrotreated at 70. This process provides significantly increased yields of desirable low-boiling hydrocarbon liquid products and minimal production of hydrocarbon gases, and no net production of undesirable heavy oils and residuum materials. <IMAGE>