A process and system for producing synthesis gas by a SPOC.RTM. enhanced catalytic partial oxidation process is disclosed. Light hydrocarbons in a H.sub.2S-containing feed gas are partially oxidized to produce hydrogen and carbon monoxide over a catalyst that simultaneously oxidizes the H.sub.2S to produce elemental sulfur. A reaction in which H.sub.2S is partially oxidized to elemental sulfur and water takes place instead of a secondary reaction in which a portion of the light hydrocarbon feed is combusted to form CO.sub.2 and water. An increase in yield and selectivity for CO and H.sub.2 products results, and readily recoverable elemental sulfur is also produced.