Conversion of coal to gas and liq. products - with by=product recycle to char gasifier

摘要

Coal conversion process comprises carbonising coal in a series of fluidised beds to produce (a) gas, (b) an oil/tar fraction contg. entrained solids, which is hydrogenated to give useful fuels, (c) a higly reactive char, which is gasified with steam in a fluidised-bed gasifier, and (d) by-products comprising heavy oil and sepd. solids coated with hydrocarbonaceous material. The improvement comprises recycling the by-prods. to the gasifier. By-product recycle increases the oil and gas yields (e.g. by 7-8%), increases the life of the hydrogenation catalysts (by removing metal contaminants) and increases the amt. of recoverable heat (c.f. US3966633 and 3966634).