A process and
system for treating a hydroprocessing unit
effluent gas
stream for recycling includes introducing the
effluent gas
stream into a
hydrogen purification zone and recovering a
hydrogen-rich gas
stream and a liquid stream containing a mixture that includes C1 to C4 hydrocarbons and H2S which is then mixed with an oxidant and fed to an oxidation unit containing catalyst for conversion of the H2S to elemental
sulfur vapors that is separated for
recovery of the elemental
sulfur, and recovering a sweetened mixture that includes C1 to C4 hydrocarbons. Alternatively, the hydroprocessing unit
effluent gas stream containing H2S is cooled, contacted with a
solvent to absorb the C1 to C4 hydrocarbons and H2S, with the
hydrogen-rich stream being recovered for recycling to the hydroprocessing unit, and the rich liquid
solvent being flashed to produce a lean
solvent stream for recycling to the adsorption zone and a
mixed gas stream that includes the C1 to C4 hydrocarbons and H2S that is passed to an
oxidation zone and is reacted with an oxidant in the presence of a catalyst to complete the process as described above for the
recovery of elemental
sulfur and a mixture that includes the sweetened C1 to C4 hydrocarbons.