Process for obtaining oil, gas, sulfur and other products from oil shale

Claim 1

A process for obtaining useful products from oil shale, comprising introducing crushed raw oil shale through the upper part of an essentially vertical processing vessel, causing said shale to move continuously downwardly as a moving bed, continuously introducing a gaseous mixture consisting essentially of oxygen and steam into the bottom of said moving bed, whereby an ascending gaseous stream continuously contacts said downwardly moving bed, said moving bed of shale passing, successively, through a drying and heating zone, a pyrolysis zone in which the temperature ranges from about 320° C. to about 700° C., a gasification zone in which the temperature ranges from about 760° C. up to the maximum bed temperature, a combustion zone and a cooling zone, withdrawing the spent shale from the bottom of the vessel, and withdrawing the resulting vapor, oil mist and gas product stream mixed with unreacted introduced steam from the upper portion of the processing vessel; said pyrolysis comprising converting the kerogen of the oil shale into essentially oil, gases and water vapor, leaving residual carbon, hydrogen and sulfur in the shale; said gasification comprising the reaction of steam with said residual carbon and sulfur in the shale to form H 2 , CO, CO 2 and H 2 S; said combustion comprising the burning of fuel matter remaining in the shale with the introduced oxygen, and serving as the source of heat required by the process, the temperature of the combustion zone being the maximum bed temperature, said temperature being controlled slightly lower than the clinkerization point of the spent shale, but being permitted to reach said clinkerization point occasionally, and the amount of steam employed being sufficient to assure such control of the maximum bed temperature and the presence of the gasification zone above the combustion zone.