Abstract: In a process for the separation of at least carbon dioxide and hydrogen sulfide from a raw gaseous mixture to form a purified gaseous mixture comprising passing said gas through a sour gas removal system including the steps of scrubbing said gaseous mixture with a liquid scrubbing agent having a higher affinity for hydrogen sulfide than for carbon dioxide, removing from said system an off-gas enriched in hydrogen sulfide, and passing said off-gas to a sulfur recovery system comprising the conversion of sulfur values to elemental sulfur and the recovery of a tail gas containing hydrogen sulfide and sulfur dioxide,the improvement which comprises hydrogenating said tail gas to convert sulfur dioxide to hydrogen sulfide and recycling resultant hydrogenated tail gas to said sour gas removal system, whereby essentially no hydrogen sulfide or sulfur dioxide is discharged into the environment.