Patent GB-147737-A (GB)
Title: Improved process of separating constituents from coke oven and like gases
IPC: C10K1/00
Filed: 1920-07-08
Abstract: 147,737. Still, C., [Firm of], Nov. 1, 1918, [Convention date]. Ammonium bicarbonate, sulphide, and cyanide sulphuretted hydrogen.-In the separation of coke oven and like gases into their constituents, the gases freed from tar are compressed to 100 atmospheres, but preferably 200 atmospheres or over, and after cooling to their original temperature that is not below 0‹ C., are treated with suitable physical or chemical absorbents for removing the different constituents. In the process described, the gases are subjected to a preliminary treatment when compressed to 20-30 atmospheres with a suitable absorbent such as alcohol for removing in part constituents such as carbon monoxide, sulphuretted hydrogen, and methane; thus, the gases pass from a water-cooled compressor 2 to a washer 4 fed with alcohol, the solution collecting in a tank 5 connected to a trunk main 7 in which gases or vapours released when the pressure is relieved, are collected. The gases are further compressed to 100-200 atmospheres in the main compressor 9, 10; ammonia separates at this point and is recovered as a saturated solution of ammonium bicarbonate, sulphide, &c. by injecting water into the cylinders 9, 10; the solution is collected in a tank 13 and the salts separate on cooling, and the mother-liquor may be returned to the compressor or used for washing the gases after they leave each cylinder. The heat of compression is removed in a condenser 16, and the gases 'then pass to a washer 18 supplied with cuprous chloride solution for removing carbon monoxide. From the washer 18 the gases pass to a washer 22 fed with tar oils &c. for washing out the benzene hydrocarbons, portions having separated as tar oil floating on the liquids in tanks 13, 19. The acetylene and ethylene hydrocarbons are absorbed by sulphuric acid in a washer 28, and the compounds obtained serve for the manufacture of ethyl alcohol and ethyl ether; the gases first meet in the lower part of the washer sulphuric acid of 50‹ Be. for removing propylene, butylene, &c., and in the upper part of the washer are afterwards treated with acid of 66‹ B. for removing acetylene and ethylene, the acid liquors being collected separately in the compartments 29, 30; these, like the tanks 23, 19, 13, 5, are connected to the trunk main 7 by which any escaping gases or vapours are returned to the inlet pipe 1. The residual gases may be used to supply by expansion energy for driving the compressors 2, 9, 10; or they may be used for the catalytic synthesis of ammonia, in which case any remaining constituents other than nitrogen or hydrogen are condensed by cooling the gases to a low temperature in an apparatus 38 which is conveniently a liquid-air float supplying the necessary quantity of nitrogen. The Specification as open to inspection under Sect. 91 (3) (a) states that ammonium cyanide is removed from the gas by the ammoniacal cuprous chloride solution and may be recovered together with the carbon monoxide by heating the solution, or may be converted into ferrocyanide. This subject-matter does not appear in the Specification as accepted.