Process for production of hydrocarbon liquid from oil shale

Abstract

A process for producing hydrocarbon liquids in preference to gases from oil shale. The shale is introduced at the top of a reaction chamber which includes an upper oil shale preheat zone having a temperature not more than about 950.degree. F., a hydroretort reaction zone at a temperature of about 850.degree. to about 1250.degree. F. and a lower hydrogen preheat zone to recover heat from spent shale. Solids from the shale are passed downwardly through the chamber so that the shale, and particularly the oil therein, is gradually heated to the reaction temperature over a relatively extended period of at least ten minutes so as to inhibit the formation of a carbon residue. A hydrogen-rich gas, containing hydrogen in excess of stoichiometric amounts needed for the hydroretorting of the oil in the shale, is passed upwardly in the reaction chamber and countercurrent to the shale solids passing downwardly therethrough. A hydroretorting reaction is promoted in the reaction chamber between the oil or organic material in the shale and the hydrogen so as to produce predominately distillable hydrocarbon liquids and a low proportion of low molecular weight paraffinic hydrocarbon gases. The process can be controlled to maximize production of aliphatic and alicyclic hydrocarbon liquids which may be utilized for wide variety of purposes including gasificaton for the production of synthetic pipeline-quality gas from oil shale.