Gas Liquor

Gas Liquor. In the manufacture of coal-gas (q.v.) a large quantity of a liquid distillate is produced and collected in suitable receivers. This distillate consists of two parts, a tarrg liquid [Coal-tar] and an aqueous. The latter, which is known as gas liquor or ammoniacal gas liquor, is, ordinarily, a slightly yellow liquid with an ammoniacal and fetid smell. It contains small quantities of tarry matters and benzene compounds and a considerable amount of ammoniacal salts, chiefly the carbonate, and sulphide. To these the gas liquor owes its commercial value, and it is largely employed for the production of ammonia and its salts, being at present almost the sole manufacturing source of these compounds. To obtain them, steam is blown through the liquor, by which means some of the ammonia salts are decomposed, and free ammonia mixed with steam passes off. Many manufacturers add lime also to the gas liquor to make the decomposition complete. The mixed steam and ammonia is then either (1) condensed, forming what is known as concentrated gas liquor, consisting chiefly of an impure solution of ammonia, or (2) is passed into sulphuric acid contained in lead chambers, by which means ammonium sulphate is produced and crystallises out. This is then either sold - being employed largely eis a manure - or used further for the production of pure ammonia and the other salts of this substance.