1258.    GRIFFITH, R. H.  Catalytic Removal of Sulfur Compounds.  Inst. Gas Eng., Copyright Pub. 175/64, 1937, pp. 45-64; Gas Jour., vol. 220, 1937, pp. 475-476, 479-485, 667; Gas World, vol. 107, 1937, p. 379-383, 471-476, 563; Chem. Abs., vol. 32, 1938, p. 6438.

       An active Ni(OH)₂ catalyst is deposited on porous china clay by soaking in a boiling solution of NiCl₂, drying, plunging the pellets into excess alkali, washing, and activating with coal gas at 350° for 2 hr.  Purified coal was passed through the catalyst bed at about 1,500 vol. per hr. per unit vol. of catalyst space at an inlet temperature 160°-180°.  In an experimental run of 40 weeks, 10,000,000 cu. ft. of gas were treated without renewal or alteration of the catalyst.  CS₂ was converted to CO₂ and SO₂ with small proportions of SO₂.  If temperature rose too high, a back reaction occurred, and H₂S was produced by hydrogenation of SO₂.  Temperature can be controlled by adjustment of O₂ in gas; the normal amount is 0.6-0.7%.  Combustion of H₂ and complete elimination of O₂ increase calorific value, permitting extraction of more benzene.  Heat requirements are met by exchange between outgoing and incoming gas.  Gas treated by the catalytic process and then by active charcoal for recovery of benzene should contain less than 1 gr. S per 100 cu. ft. of gas, no O₂, no NO, and a considerably lowered % of diolefin hydrocarbons.  It should be free from formation of gummy deposits and produce only traces of SO₂ on combustion.