Process for purifying gases containing H2 S

Claim 1

A process for preparing sulfur by continuously removing sulfur compounds from a fuel gas stream containing H 2 S or H 2 S and a small quantity of SO 2 , which comprises (1) bringing into contact a fuel gas stream containing H 2 S with a stream of organic solvent that dissolves H 2 S and SO 2 well, so as to remove the H 2 S and SO 2 , if present, from said gas stream (2) mixing most or all of the solvent stream discharged from step (1) and a stream of organic solvent containing SO 2 , the amount of SO 2 contained in said solvent being stoichiometrically less than that of H 2 S in the mixed solvent, under reaction conditions so selected as to produce elemental sulfur and a stream of organic solvent containing dissolved unreacted H 2 S, and retaining the mixed streams for a time sufficient to insure that substantially no unreacted SO 2 remains within the stream of organic solvent; (3) separating the solvent stream containing dissolved H 2 S of step (2) from the elemental sulfur; (4) separating the organic solvent stream containing dissolved H 2 S from step (3) into a stream of gas containing H 2 S and a stream of organic solvent free of H 2 S and returning a part of said organic solvent stream free of H 2 S to step (1); (5) oxidizing the gas stream containing H 2 S from step (4) under oxidizing conditions so as to produce SO 2 ; and (6) contacting the gas stream containing SO 2 from the step (5) with a part of the organic solvent free of H 2 S from step (4) to produce a stream of purified gas free of SO 2 and a stream of organic solvent containing dissolved SO 2 which solvent stream is returned to step (2).