Partial combustion retorting of several kinds of oil shales.

Abstract

A retorting study was conducted on eleven kinds of oil shales using a partial combustion retorting method (PCM). Every oil shale studied could be retorted with air alone without introducing any external energy. The oil shales whose Fischer assay oil yields were not less than 9% had total oil yields in the range from 81 to 105% based on the Fischer assay oil yields, while those oils having yields less than 9% were significantly lower than the others. In the case of Condor oil shale, part of the oil vapor was thought to be burned during the partial combustion retorting to compensate for the shortage of thermal energy supplied by the combustion of the carbon residue on the spent shale due to its low organic carbon content. Combustion of the spent shale seemed to require an amount of air proportional to the percentage of the aromatic carbon in the raw oil shale. Shale oils obtained by PCM had slightly higher densities and H/C ratios, and lower quantities of lighter fractions than those obtaind by Fischer assay.