GB605634A - Improvements in or relating to the purification of coke oven gas - Google Patents

Abstract

605,634. Gas scrubbing processes; revivifying purifier waste. KOPPERS CO., Inc. Jan. 1, 1946, No. 93. Convention date, Feb. 20, 1945. [Class 55(ii)] The heat of effluent from a collecting main 48 of a coke oven battery is utilised to generate vapour under sub-atmospheric pressure in a fouled absorbent liquid regenerator 26 and thereby sweep absorbed constituents as a gas from the liquid which is returned via a water-pipe cooler 82 to the absorber 4. A vacuum pump 40 withdraws the gases through condensers 32, 36, collecting exhaust steam which is returned as condensate to the base of the absorber. Flushing liquor from the collecting main passes through a settling tank 54 for separating tar before being pumped through the coils of a reboiler 66 immersed in absorbent liquid at the base of the regenerator, and thence returned to the main cooler than in normal practice whereby a thinner tar is condensed and the load on primary gas coolers relieved. Steam condensed from the gases leaving the regenerator is returned to the base of the absorber. In one modification regenerated solution under slight pressure is heated by indirect contact with flushing liquor and then vaporized in the regenerator; in another vapours from the flushing liquor itself evolved in a low pressure zone are passed through the fouled absorbent. Hydrogen sulphide, hydrogen cyanide carbon dioxide and ammonia may be absorbed by aqueous absorbents such as water or solutions of alkaline metal carbonates and bicarbonates or other salts, or weak bases such as organic amines. A straw oil may remove light oil and carbon disulphide, the light oil being stripped off by the heat from the flushing main liquor, and purified of hydrogen sulphide by alkaline solution afterwards regenerated by heat from the main liquor. Specification 597,598 is referred to.