Tail Gas from the Claus section still contains unrecovered sulfur species: H2S and SO2, residual COS and CS2, traces of vapor and liquid elemental sulfur.
To further increase recovery yields, tail gas leaving the Claus section can be treated using different processes. Axens proposes dedicated technologies and products for sub-dewpoint applications or hydrogenation plus amine process (Sultimate™) where sulfur species are reduced back to H2S and recycled to the Claus section inlet. These optimized catalysts help reaching the ever-increasing stringent specification on sulfur emissions.