Apparatus and method for the gasification of solid carbonaceous material

Abstract

A process and apparatus are provided for converting particulate carbonaceous fuel, such as high-sulfur bituminous coal, into a combustible gas, the process comprising forming an ignited fluidized bed of said particulate carbonaceous fuel in a closed-bottom shaft furnace, the shaft furnace having a roof enclosure, directing a jet stream of oxygen downward into the bottom zone of said ignited fluidized bed of particulate fuel by means of an oxygen lance passing axially through said roof enclosure in sealing engagement therewith, the velocity of said oxygen stream into said bottom zone being sufficient to form a dynamic highly turbulent suspension of said particulate fuel and its particulate reaction products deflecting substantially radially outwardly and upwardly and then inwardly and downwardly in a toroidally circulating manner in the bottom zone of said fluidized bed, continuously removing effluent gases formed by the reaction of said oxygen with said fluidized bed, and maintaining said fluidized bed by continually feeding makeup fuel to said shaft furnace. When the jet-fluidized bed is operated continuously below ash-fusion temperatures, said bed will accumulate and maintain a high percentage of particulate ash which is continuously withdrawn from the furnace. When the jet-fluidized bed is operated above ash-fusion temperatures and fluxes and sulfur fixation agents are fed with the coal, a molten bath is formed on the bottom of the furnace, said bath serving to collect ash, sulfides, iron, and other coal impurities in molten products which flow out of the furnace through tap holes.