GB827153A - Removing hydrogen sulphide from gases - Google Patents

Abstract

827,153. Purifying gases. GAS COUNCIL. Jan. 31, 1957 [Feb. 10, 1956], No. 4312/56. Class 55 (2). In a process for removing hydrogen sulphide from gases, e.g. coal gas, which consists in alternately washing the gases with a liquid comprising a solution or suspension of an organic compound which will yield a readily oxidizable reduction product on contact with hydrogen sulphide, and bringing the liquid containing the reduction product into contact with air or oxygen to oxidize the reduction product back to the original compound, the process is so conducted that during absorption of hydrogen sulphide there is at all times an excess of the organic compound in its non-reduced form while during the oxidation with air or oxygen there is at all times an excess of the organic compound in its reduced form. Suitable organic compounds are certain dyes, e.g. methylene blue, used in solution in a solvent, e.g. aniline, in conjunction with a catalyst, e.g. pyridine or quinoline. In an example the oxidized solution passing into the absorber contains 1.5% methylene blue in the non-reduced form and 0.5% in the reduced form and the solution leaving the absorber and passing to the oxidizer contains 1.5% methylene blue in the reduced form and 0.5% in the non-reduced form. Specifications 827,151, 827,152, [Group III], and 827,154 are referred to.