A sulfur species-containing feed gas is processed in a treatment plant in which COS is hydrolyzed, and in which so produced hydrogen sulfide and other sulfur species are absorbed in a lean hydrocarbon liquid. The sulfur species in the so formed rich hydrocarbon liquid are then subjected to catalytic conversion into disulfides, which are subsequently removed from the rich solvent. Most preferably, sulfur free lean solvent is regenerated in a distillation column and/or refinery unit, and light components are recycled from the rich hydrocarbon liquid to the absorber.