A method of washing and cooling gases from the gasification of coal

摘要

In the washing and cooling of gas generated in the pressure gasification of coal in a stationary bed in which the gas is washed and directly cooled in a washing cooler with a circulating liquor and subsequently further cooled in indirect gas coolers the pH of the circulating liquor in the washing cooler is maintained above 9.5 by introducing condensate obtained from the indirect gas coolers. The recycled condensate may be introduced into the circulating liquor direct and/or into the gas stream at the head of the washing cooler and the amount may be automatically regulated by the pH's of the liquor and condensate. Tar and oil constituents in the condensate may be removed at operational pressure or after decompression or the complete condensate may be recycled.