Extracting shale oil from oil shale - using pyrolyzer receiving heat carrier from combustor in which carbon on spent shale is burned

摘要

Shale oil is extracted from oil shale by separating a finer fraction from the raw shale feed and preheating the remaining larger soze fraction by contact with finely-divded hot shale ash and hot gas coming from a fluidised bed spend shale combustor. The preheated shale fraction is separated from the ash and fed together with the fines fraction to a pyrolyzer which receives a finely-divided heat carrier from the combustor and a supply of hot fluidisation gas. Heat carrier and smaller spend shale particles leaving the pyrolyzer are separated from the larger spent shale particles and are fed direct to the combustor while the larger spent shale particles are fed to the combustor via pulveriser.