Process for treating a gas containing hydrogen sulphide and sulphur dioxide

A process for the treatment of a gas containing hydrogen sulphide (H2S) and sulphur dioxide (SO2), comprising contacting said gas with an organic solvent containing a catalytic system which is soluble in said solvent, and recovering a gaseous effluent which is depleted in hydrogen sulphide and sulphur dioxide along with liquid sulphur separated from the solvent by liquid-liquid decantation, wherein in the process said catalytic system comprises at least one compound comprising at least one functional group A consisting of a carboxylic acid function and at least one compound, which may or may not be distinct, comprising at least one functional group B comprising at least one nitrogen atom and which can carry out an acid-base type reaction with at least one functional group A under the implementation conditions of said process, said catalytic system excluding any alkali metal or alkaline earth metal salts of organic acids.