GB688915A - Improvements in or relating to the production of gas - Google Patents

Abstract

688,915. Gasifying solid or liquid fuels. ENTREPRISE GENERALE DE CHAUFFAGE INDUSTRIEL PILLARD FRERES & CIE. March 14, 1950 [March 14, 1949], No. 6415/50. Classes 55 (i) and 55 (ii) [Also in Group XXX] Powdered or liquid fuels are gasified in an elongated reaction vessel comprising zones 8, 24 and 25 in admixture with a gas containing free oxygen and steam, the mixture being introduced into the zone 8 under a pressure of 20-25 kilogrammes per sq. cm. and the resulting gases progressively cooled as they pass up the vessel through zones 24 and 25, the crosssectional area of the zone 25 being greater than that of the zone 8 to give a residence time of the gases in that zone of about 30 secs. and allow formation of methane. The reaction vessel comprises an inner shell 6 lined with refractory material 7 at its lower end and an outer shell 4, the space between the shells 4 and 6 forming a water jacket which cools the gases. The fuel is injected into the zone 8 through a series of nozzles 27 by means of steam, preferably superheated, from a boiler 32a and oxygen is admitted from a line 49 through the concentric nozzles 28, the arrangement being such that the injected substances are violently agitated and almost complete gasification is effected in the zone 8. All the steam for the process may be supplied to the zone 8 but steam may also be admitted through pipes 62 to control the temperature in the zone 25, the temperature of the gases leaving the zone 8 at 1000‹- 1200‹C being reduced to about 300‹C at the gas outlet 26. The fuel-steam mixture charged into the zone 8 may be supplied by apparatus (see Group XXX) comprising a hopper 37 and an ejector 33 which is arranged in the line 30 connecting the boiler 32a with the nozzles 27. The supply of oxygen may be regulated automatically to the flow of steam in the line 30 by utilizing the pressure drop across an orifice 51 arranged in the line 30 to actuate a control valve in the oxygen supply line 49. The base of the gasification zone 8 has an outlet 9 to allow discharge of any ash not entrained in the gases produced. The unpurified gases obtained may have a composition of CO 2 20-25 per cent, CO 16-18 per cent, H 2 20-22 per cent, CH 4 20-22 per cent and inerts 15-20 per cent. The CO 2 content is reduced by any suitable means to less than 5 per cent.