PROCEDE POUR L'OBTENTION DE SOUFRE ELEMENTAIRE A PARTIR DE GAZ RICHES EN ANHYDRIDE CARBONIQUE CONTENANT DES COMPOSES SOUFRES ET DES IMPURETES

A process for recovering elemental sulfur from gases containing inorganic and/or organic sulfur compounds together with large quantities of carbon dioxide and other possible impurities such as unsaturated hydrocarbon and hydrogen cyanide. The waste gas is combined with a combustion-promoting gas and the resulting mixture is burned with a slight excess of air and caused to contact coke at a temperature of 300 DEG to 450 DEG C. The resulting gas, from which oxygen, sulfur trioxide and nitrogen oxide have been removed, by contact with the coke, is cooled to 20 DEG to 80 DEG C and then is scrubbed with aqueous alkali salts of weak inorganic and/or organic acids or amines to remove SO2. The absorbent is stripped and the recovered SO2 is reacted with hydrogen at 200 DEG to 400 DEG C to form sulfur and/or hydrogen sulfide and, when hydrogen sulfide is produced, the latter is reacted on alumina or activated carbon at 200 DEG to 300 DEG C to produce the elemental sulfur. All or part of the gas after recovery of the elemental sulfur is recycled.