Purificn of gas derived from gassification of coal under press - for refval of tar, dust and optionally hydrogen sulphide using oil washing

摘要

In the purification of gas derived from the gasification of coal under pressure, to remove dust, heavy hydrocarbons and entrained H2S by washing with a wash liquid, a wash oil, preferably a tar oil, is used. Advantageously, the wash oil is circulated in closed circuit from which solids and tar are separated continuously and recycled to the gasification reactor. Prevents the blockage of the washing plant liable to occur with water washing as well as reducing the heat losses and the amount of water vapour in the washed gas.