RI 2588 Fractional "Eduction" Of Oil From Oil Shale. ? Introduction

[The theory of fractional "eduction" of oil from oil shale has been used by several inventors as the basis for the design of retorts for the production of oil f roan the oil shales of the United States. The term fractional "eduction" gives expression to the rather common belief that when an oil shale is he-test et produces light, low-boiling oils at to temperatures, and increasingly heavier, higher-boiling oils as the temperature of retorting rites. The theory evidently had its is origin in the fact that crude petroleum may be fractionally distilled, yielding light oils at low distillation temperatures, and heavier oils as the distillation temperature increases. Thus, gasoline is produced from petroleum at relatively log: temperatures, kerosene at a higher temperature, and heavier products such as gas-oil and lubricating distillates at still higher temepratures, The writers have examined several oil-shale retorts designed to take advantage of the belief that crude, and en some cases refined, gasoline can be recovered from the shale at low temperatures; kerosene at higher temperatures, and so on. Such retorts are usually designed to operate continuously, and. have several vapor-pipes lending from them at differing intervals and passing to separate condensers. Designers of such retorts expect that the distillate from the low-temperature parts of the retort will be gasoline, and that as the shale basses to zones of increasingly higher temperatures, the vapor lines leading from these zones will remove increasingly heavier products such as kerosene, gas-oil, etc.]