Chemical examination of the organic matter in oil shales, A

Abstract

Samples of oil shale from DeBeque (Colo.) were examined by a microscope at a magnification of 50 diameters. Thin sections showed clear quartz grains, dense black grains of pyrite coalesced to form irregular masses, mixed clay substances, sericitic products, and carbonates. Oil shales were treated with sulfur dioxide, selenium oxychloride, sulfuryl chloride, and chlorine gas. Oven-dried oil shale from DeBeque (Colo.) of 40- to 60-mesh per inch size was extracted with various solvents in a Sohxlet-type apparatus. Only part of the kerogen of the shale could be extracted by solvents, and the material extracted did not appear to be an oil and only resembled oil when subjected to destructive distillation. Samples of raw oil shale and pyrolyzed shale from Grand Valley (Colo.) were heated side by side under the same conditions. The extent to which the temperature of the raw shale became higher or lower than the ''spent'' shale in the various pyrolytic stages was determined. The oil shale showed an endothermic reaction from 350 to about 400/sup 0/C followed by an exothermic change from 395 to 420/sup 0/C. Except for small variations, the reaction was still exothermic up to about 500/sup 0/C, and it became markedly exothermic above this temperature. These results indicated that the organic content of the shale consists of a mixture of substances. Redistillation of the intermediate product obtained by vacuum retorting of oil shale increased the content of saturates 27 percent.