Abstract: Hydrogen sulfide is removed from gas streams by reaction with sulfur dioxide to produce sulfur. The reaction is effected in a reaction medium comprising a non-aqueous Lewis base with a pKb value of about 6 to about 11.

Abstract: Hydrogen sulfide is removed from gas streams by reaction with sulfur dioxide to produce sulfur. The reaction is effected in a reaction medium comprising a non-aqueous Lewis base with a pKb value of about 6 to about 11. The reaction medium possesses a specific combination of properties: a) absorbs sulfur dioxide and reacts chemically therewith to form a reaction product; b) absorbs hydrogen sulfide; c) removes the hydrogen sulfide from the gas stream through contact of the gas stream with the reaction medium in the presence of free sulfur dioxide, and/or the reaction product; d) acts as a catalyst for the overall reaction of the hydrogen sulfide with sulfur dioxide to produce sulfur; and (e) has the capacity to absorb sulfur dioxide in sufficient quantity to remove substantially all the hydrogen sulfide from the gas stream, notwithstanding short term variations in the stoichiometric balance between the hydrogen sulfide and the sulfur dioxide in the reaction medium.

Abstract: Hydrogen sulfide is removed from gas streams by reaction with sulfur dioxide in an autogeneously-formed aqueous acid medium according to the equation: SO.sub.2 +2H.sub.2 S.fwdarw.2H.sub.2 O+3S the sulfur being removed from the aqueous phase. Carbonyl sulfide and/or carbon disulfide is removed from gas streams by hydrolysis to hydrogen sulfide in the presence of a weak organic base catalyst, such as quinoline, with the hydrogen sulfide reacting with sulfur dioxide to form sulfur.