GB668808A - Process for retorting shale - Google Patents

Abstract

668,808. Distilling oil shale. CALIFORNIA RESEARCH CORPORATION. Sept. 14, 1950 [Sept. 17, 1949], No. 22628/50. Class 55 (i). The gases and vapours evolved from oil shale which is distilled by contact with hot gas previously recovered from the shale, are cooled by direct counter-current contact with the incoming fresh shale, the normally liquid constituents condensing out and being withdrawn separately from the gases, which are heated and returned to the distillation zone. In the apparatus shown in the Figure the shale is fed from a line 1 to the lower end of a conveyer-condenser 3, which consists of an inclined tube opening at its upper end into a retort 4 and containing a conveyer chain 5 which carries the fresh shale to the feed-pipe 8 of the retort. Hot recycled shale gas enters the retort through a line 9, and distils the shale therein at about 1000‹ F. The distillation vapours and gases pass out through pipe 8 into the condenser 3, the condensed oils being withdrawn through a line 21 and fixed gases through a line 22. The spent shale passes from retort 4 into a kiln 12 where it is in part burnt by air entering through a line 13, the combustion gases passing out through line 14. The shale, heated to about 1220‹ F., passes down into a cooler 17, cool recycle gas entering through a line 18 and leaving through line 9, to enter the retort at about 1050‹ F. Spent cooled shale is withdrawn from the cooler through line 19. The gases from the condenser 3 pass through a second condenser 23 and gas-liquid separator 24 to a pump 27 which discharges product gas through a line 28 and recycle gas through the line 18. In a modification, Fig. 3 (not shown), the fines are screened from the fresh shale and passed into the retort, kiln and cooler entrained in the entering gases to form a fluidized bed above the mass of coarse particles, which pass through the plant as described above. In a further modification the kiln 17 is omitted, the gases to the retort being heated by partial combustion in an external combustion chamber, Fig. 4 (not shown).