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Abstract

A process is provided to recover residual H.sub.2 S, SO.sub.2, COS and CS.sub.2 in the tail gas from a sulphur recovery process. The tail gas is oxidized and hydrolyzed at a temperature of from 180.degree. C. to 700.degree. C. to provide an oxidized and hydrolyzed gas stream containing substantially no COS or CS.sub.2 and having a concentration by volume of H.sub.2 S and SO.sub.2 such that the H.sub.2 S concentration minus twice the SO.sub.2 concentration is from 0.25% to 0.5%. Then the gas stream from the hydrolysis is passed over a Claus catalyst, for example based on alumina and/or titanium oxide, for the reaction of H.sub.2 S with SO.sub.2 to form sulphur and provide a gas stream with substantially no SO.sub.2. The resulting gas stream from the Claus reaction together with a gas containing free oxygen is then passed over an oxidation catalyst, such as one of more oxides or salts of Ni, Co, Fe, Cu, Ag, Mn, Mo, Cr, W or V, deposited on a support, such as bauxite, activated aluminia, silica, titanium oxide, zirconium oxide, zeolite or activated carbon to form sulphur and release a purified gas stream containing substantially no sulphur compounds.

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First Claim