GB832075A - Improvements in or relating to the desulphurisation of coke oven gases - Google Patents

Abstract

832,075. Purifying gas. BERGWERKSVEBBAND G.m.b.H., [formerly BERGWERKSVERBAND ZUR VERWERTUNG VON SCHUTZRECHTEN DER KOHLENTECHNIK G.m.b.H.]. Nov. 2, 1956 [Nov. 28, 1955], No. 33536/56. Drawings to Specification. Class 55 (2). In a process for removing hydrogen sulphide and ammonia from coke-oven gas, effluent from an ammonia scrubber and condensate from the gas coolers, and possibly also condensate from the compressor used to compress the partly purified gas, are introduced into the collecting main of the coke-oven producing the gas, liquor from the collecting main is detarred and used to scrub the coke-oven gas after the gas has been cooled, the gas flow velocity in the scrubber being between 1 and 5 m./sec., the gas from this scrubber is then compressed, e.g. to between 5 and 20 atmospheres, cooled and scrubbed with the effluent liquor from the first scrubbing stages maintaining a gas flow velocity between 1 and 5 m./sec., and finally the gas is scrubbed with fresh water to remove any remaining ammonia, the resulting liquor being returned to the collecting main. The detarred collecting main liquor may be divided into two portions, one of which is fed directly to the second stage scrubbing. Ammoniacal liquor containing little carbon dioxide may be fed to the second stage scrubbing, the liquor being obtained from a middle section of an ammonia still distilling the effluent liquor from the second stage scrubbing or from the vapours leaving such a still. The second stage scrubbing is preferably carried out at temperatures below 10‹ C.