GB683027A - Improvements in or relating to the gasification of solid carbonaceous materials - Google Patents

Abstract

683,027. Distilling and gasifying carbonaceous solid material. HYDROCARBON RESEARCH, Inc. June 30, 1949 [July 20, 1948], No. 17326/49. Class 55 (i). A process of carbonising and gasifying a carbonaceous feed material with volatile constituents, e.g. coal, lignite or oil shale comprises mixing particles of this feed material with particles of carbonised material free from volatile constituents and withdrawing from a carbonisation zone, passing this mixture directly into the lower part of a fluidised bed of carbonaceous particles in a carbonisation zone 11 in which volatile constituents are distilled by the addition of a hot gas from a gasification zone acting as the fluidising medium, discharging the resulting gases at 25 and withdrawing the carbonised material through a pipe 17 and passing it to a gasification zone 12 to which steam and oxygen are supplied by pipes 18, 21, the hot effluent gas passing up a pipe 13 to heat and fluidise the mixture in the carbonisation zone 11, the residual solid being discharged through a pipe 23. Fine coal particles are fed from a container 7 held under pressure with inert gas by a pipe 8 through a conveyer 9 into the pipe 13 through which the hot gases at 2000‹F. rise from the gasifying zone 12 and char from the carbonising zone is fed by a pipe 14 at lower point to the pipe 13, so that a fluidised mixture is carried into the carbonising zone 11. A high class char may be drawn off the pipe 17 through a pipe 19 and a low class char is drawn off the gasifier at 23. A centrifugal separator 24 frees the product gas from dust. The gasifier is under a pressure of 350 lbs. per sq. in. and some solid may pass therefrom through pipe 13 to the carboniser. In Fig. 2 a portion of the effluent gas from the gasifier 32 is drawn off separately through a pipe 47, is passed through a dust separator 48 and is cooled to below 1500<SP>o</SP>F. by water from a pipe 50 to prevent reaction between carbon monoxide and water vapour before rising to meet the product gas at 39 from the carboniser 31. Carbonised material entrained with the gases from the carboniser passing to the outlet 37 is separated at 38, and the char is returned through a pipe 43 in part to the gasifier 32 and in part through pipe 42 to the carboniser. The mixture fed to the carboniser preferably comprises 5 parts of char to one of coal. The carboniser is cooled by water pipes 36 forming a steam generator. Char direct from the carboniser, which is maintained at 900-1300‹F., may be fed through the pipe 44 to the mixing pipe 33. Residual char from the gasifier, which is maintained at 1600-2000‹F. is removed through a pipe 52 for use as fuel or passes through pipe 53 into a gas generator 54, e.g. where it is burnt with oxygen from the pipe 56, the product gas passing off at 57 and ash being removed at 58.