Process for the gasification of coal

摘要

Coal particles are dried in a drying zone 10 and are then preheated in a preheater 12 to a temperature just below the pyrolysis temperature. Next the coal is pyrolysed in a retort 20 by contacting it with heat carrying solids and in a non-oxidising atmosphere, to remove substantially all of the tar-forming volatile combustible matter from the coal particles and produce substantially tar-free coal char particles and also volatile vapours and condensible gases. The devolatilised tar-free char particles are then contacted with steam and an oxygen -containing gas in a gasifier 30. The gasification in the gasifier 30 produces a combustible gas which is tar-free can and is ideally suited for combustion, for example to produce combustion gases for driving a gas turbine 54.