GB217183A - Improvements in or relating to the purification of gases intended for the manufacture of hydrogen for use in the synthetic production of ammonia - Google Patents

Abstract

Gases such as water gas and coke oven gas employed as a source of hydrogen intended for the synthesis of ammonia are freed from carbon dioxide and sulphuretted hydrogen by scrubbing with an ammoniacal liquor produced in an ammonia-soda process of the Schrieb type, and the solution of carbonate and sulphur compounds thereby obtained is subsequently utilized in said process. In the Schrieb modification described in Specification 160,172 the liquor used for purifying the gases is that obtained by adding ammonia or alternatively, ammonia and salt to the mother liquor obtained after separation of ammonium chloride. In the case of the Schrieb modification described in Specification 131,870 the mother liquor resulting on precipitation of sodium bicarbonate is employed after addition of ammonia and sodium chloride; or sodium chloride is added to the same mother liquor and ammonia added after ammonium chloride has been separated by cooling. Purification may be effected before or after compression of the gas which is caused to pass up towers packed with Rasching rings, plates, &c. irrigated with the ammoniacal liquor. Since ammonia escapes with the purified gas, the latter is passed up packed towers irrigated with water or sulphuric acid, yielding, in the latter case ammonium sulphate which is separated by crystalization.