Improvements in the manufacture of gas and in particular of gas for the synthesis ofammonia

摘要

677,643. Gasefying solid carbonaceous materials. COMPAGNIE PAN - EUROPEENE D'INSTALLATIONS ET D'EQUIPEMENT INDUSTRIELS. June 2, 1949 [June 8, 1948; Feb. 21, 1949], Nos. 14876/49 and 14877/49. Class 55 (i). Finely-divided carbonaceous material is suspended in a preheated gasefying mixture of air or oxygen and steam in a first zone and into the gas produced or a part of it, while still containing some ungasefied material and retaining the heat of the first operation, is introduced in a second zone a supplementary amount of oxygen and steam to continue the gasefication of the material. Powdered coal or lignite introduced into a generator 3 through a nozzle 6 is suspended in steam and air or oxygen (e.g. a mixture of 62 per cent steam and 38 per cent air) preheated to 800-1400‹ C. in one of a pair of regenerators 1, 2, and distributed through a perforated dome 5, a gas mixture being produced in which the ratio of hydrogen and carbon monoxide to nitrogen may be rather more than 2: 1. Part of this gas is diverted through a conduit 12, boiler 19, dust separator 20 and washers 21, 22, back to heat the other regenerator by combustion with air admitted through a pipe a. The rest of the gas passes through a two-pass generator 9 into the first leg of which oxygen and steam is admitted through apertures 11 to gasefy residual coal and, if desired, an additional supply resulting in a mixture in which the hydrogen and carbon monoxide to nitrogen ratio is about 3: 1 and which, after replacement of the carbon monoxide by hydrogen by reaction with steam, may be utilized for the synthesis of ammonia. The coal dust may be conveyed to the plant in nitrogen available from the oxygen-producing means. In a modification for sulphur-containing coal, a slight pre-distillation of the fuel at low temperature, e.g. 300-400‹ C., is effected by introducing it into the gas diverted into conduit 12, the temperature being regulated by by-passing a controlled portion of the gas before the point of entry of the coal. Carbon monoxide-hydrogen gases for other syntheses and composed, e.g., of H 2 46.3, CO 38.8, CO 2 14.9, may be obtained by employing steam and oxygen mixtures, e.g. in the ratio 17: 3, heated to 1000-1300‹ C., all of the gas passing from the first to the second generator. A simple shell may enclose both generators. Several plants may be operated to supply both ammonia synthesis gases and water gas &c., all the regenerators being heated by producer gas from one of them.