GB364201A - Improvements in or relating to the production of ammonium salts - Google Patents

Abstract

Gases containing ammonia and non-oxygenated sulphur compounds, such as hydrogen sulphide, are passed with oxygen or gases containing oxygen at a temperature up to 400 DEG C. and at ordinary or raised pressure over a catalyst comprising an oxide of nickel and/or cobalt mixed with a subexcess of a water-insoluble or difficultly soluble compound of calcium, barium, magnesium, and/or silicon. The ammonium salts so produced are separated by cooling or in an electrofilter. Industrial gases such as coke-oven gases or distillation gases may be treated directly, or the ammonia may be washed out from the gases and then subjected to the treatment together with hydrogen sulphide obtained either from the gases or in any other way: for example, the hydrogen sulphide in the gases may be converted into iron sulphide and the latter then decomposed. According to the examples (1) a mixture of coke-oven gas with 10 per cent of air is passed at 190 DEG C. over a mixture of gypsum with 2 per cent of cobalt oxide; (2) a mixture of coke-oven gas with 9 per cent of air is passed at 245 DEG C. over a mixture of magnesium oxide with 4 per cent of nickel oxide; examples are given also of the treatment of coke-oven gases in the presence of mixtures of lime with 2 per cent of nickel oxide or with 1,5 per cent of cobalt oxide. The Specification as open to inspection under Sect. 91 (3) (a) refers to the conversion of non-oxygenated sulphur compounds, such as hydrogen sulphide, into sulphur oxides with the aid of the catalysts described above. This subject-matter does not appear in the Specification as accepted.