A system for reducing SO2 emissions comprises a hydrogenation reactor, a tail gas cooler, a contact condenser, a hydrolysis reactor, and an absorber. The hydrogenation reactor is configured to receive a Claus tail gas and convert at least a portion of SO2 in the Claus tail gas to H2S to produce a hydrogenated Claus tail gas stream. The hydrolysis reactor is configured to convert at least a portion of COS to H2S. The absorber comprises an amine-based solvent and is configured to absorb at least a portion of the H2S and recycle the H2S to the Claus plant.