Recovery of hydrocarbon values by controlled eduction and oxidation of oil shale

摘要

In the process for recovering energy values from oil shale by the cross-flow retort technique, an improvement is disclosed wherein controlled oxidation of non-vaporizable carbonaceous residue not only provides additional heat for the continuation of the oil educing process without application of external heat but also enables the continuation of a temperature profile which is below that at which adverse chemical and physical changes occur in the shale. According to the invention the moving bed is removed from exposure to external heat as soon as oil eduction has been completed in the upper bed regions. It is thereafter immediately exposed to unheated gases containing measured amounts of oxygen. Oxidation is initiated in those regions of the bed which are above about 800° F. The heat generated by such oxidation may be utilized, in place of externally heated gases, to transfer heat to the lower regions of the bed for oil eduction from those lower regions.