Retorting of shale

Retorting of shale is the most commonly considered method for oil recovery from the rock. Despite the apparent simplicity of retorting, it is a complex process. This complexity is due to the lean nature of the ore, the requirement to add heat at high temperature, and the chemical and physical changes which take place in retorting. 

Some insight into the utility of shale oil can be gained by comparing its composition with coal-derived liquids and petroleum crude oil. See Table III. Two representative liquid products from coal are shown COED product, produced by carbonization or coking, which, like retorting of shale, is a thermal step (4), and a liquid from the H-Coal process by coal hydrogenation (5). Arabian Light crude oil is also shown. 

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