Oil Shale

Abstract Oil shale, found in numerous geologic deposits throughout the world, has been used commercially on a very limited scale. The organic matter in oil shale exists as a complex, high molecular weight solid polymer in an inorganic rock matrix. Production costs for crude shale oil are generally much higher than those for conventional crude oil, in part because of the high concentrations of heteroatoms in the crude shale oil. Refining costs are also higher. Retorting processes for oil shale, as well as the upgrading processes needed to refine the crude shale oil into fuels and other products, are described. Shale oil asphalt is the most promising of these products. Several commercial oil shale operations exist, but these are all outside of the United States.