GB744153A - Process of gasifying solid combustible materials - Google Patents

Abstract

744,153. Gasifying solid fuels. UNION RHEINISCHE BRAUNKOHLEN KRAFTSTOFF AKT.-GES. June 8, 1953 [June 19, 1952], No. 15767/53. Class 55 (1). In a process of producing combustible gases by gasifying solid fuels in a bath of their own liquid slag which is maintained in a cyclic current between a heating space 1 and a gasifying space 2 wherein the fuel is gasified by introduction of an endothermic gasifying agent, e.g. steam, the gases produced in the space 2 are treated after they have left the slag to increase the hydrocarbon content thereof by adding fuel thereto while avoiding contact between the fuel thus added and the slag. The fuel added to increase the hydrocarbon content may be coal, lignite, peat, oil shale or a liquid or a gaseous fuel and it may be added at a point at which the heat emitted by the slag is still effective. The heat, of the slag bath may be effective only for a short time to produce unsaturated hydrocarbons and the gases are then chilled or otherwise treated to preserve the equilibria of the unsaturated hydrocarbons produced. In the form shown, the gasifying apparatus is adapted to use a solid fuel, e.g. lignite, as the fuel for enriching the gasification gases also includes a distillation space 3, a coke separator 4, a fuel drier 5, a separator 6 for separating the fuel dried whilst in suspension in hot gases, a washer 7, a waste-heat boiler 8 and a feed-water pre-heater 9. Ducts 15 and 16 supply air and feed-water, and the duct 17 leads flue gas from the heating space 1 to the outer atmosphere, and the duct 18 removes steam from the boiler. Lignite pre-dried to 15 per cent water content is fed from line 10 into the hot gas stream from the distillation space 3 and is carried through the drier 5. Dried lignite containing 2 per cent water is led partly by duct 11 to the gasifying space 2 with the aid of steam or other conveying medium introduced through duct 12, and partly by duct 14 to a point where it is entrained in the hot gases leaving the gasifying space 2. Steam may be added to the gases entering the distillation space 3 through duct 13. The fuel not gasified in space 2 is carried in the slag into the heating space 1 and coke is added by a duct from cokeseparator 4. The slag is reheated by combustion of the fuel contained therein with air added by duct 15 and combustion gases pass out through waste heat boiler 8, feed-water pre-heater 9 and duct 17. Coke from separator 4 may also be added to the gasifying space 2. The hot gases leave the gasifying space 2 at about 1500‹ C. and after passing through the distillation space 3 and coke separator 4 enter the coal drier at about 750‹ C. Combustible gas is led off by duct 19. In a modification the gases leaving the gasifying space may be enriched by passing the gases over a catalyst, e.g. one containing nickel, to convert some of the carbon monoxide and hydrogen into methane and water. Specification 666,119 is referred to.