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.