| 摘要 |
A process for catalytic two-stage hydrogenation and liquefaction of coal with selective extinction recycle of all heavy liquid fractions boiling above a distillation cut point of about 600 DEG -750 DEG F. to produce increased yields of low-boiling hydrocarbon liquid and gas products. In the process, the particulate coal feed is slurried with a process-derived liquid solvent normally boiling above about 650 DEG F. and fed into a first stage catalytic reaction zone operated at conditions which promote controlled rate liquefaction of the coal, while simultaneously hydrogenating the hydrocarbon recycle oils. The first stage reactor is maintained at 710 DEG -800 DEG F. temperature, 1000-4000 psig hydrogen partial pressure, and 10-90 lb/hr per ft3 catalyst space velocity. Partially hydrogenated material withdrawn from the first stage reaction zone is passed directly to the second stage catalytic reaction zone maintained at 760 DEG -860 DEG F. temperature for further hydrogenation and hydroconversion reactions. A 600 DEG -750 DEG F.+ fraction containing 0-20 W % unreacted coal and ash solids is recycled to the coal slurrying step. If desired, the cut point lower boiling fraction can be further catalytically hydrotreated. By this process, the coal feed is successively catalytically hydrogenated and hydroconverted at selected conditions, to provide 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.
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