2286. MINCHIN, L. T. Liquid Purification – Some British and Continental Developments. Coke and Gas, vol. 13, 1951, pp. 27-29.
Some of the more recent processes and plant for removal of H2S from town gas or coke-oven gas by liquid reagents are described: The Dutch State Mines-Otto process, which uses a washing liquid containing initially ferrous sulfate and potassium ferrocyanide; the Collin process installed at Duisburgi n the Ruhr district of Germany using NH3 liquor of about 6 oz. strength in the form of a spray; the Szombathy process, which uses an aqueous solution of sodium thiosulfate and a water-soluble catalyst (not given), which functions as an O carrier and oxidizes the H2S to H2O and S. The H. Koppers Co. owns the patents. Test results are not yet available. A full-scale plant to deal with 7 million cu. ft./day is under construction.