An advanced process is developed for the separation of H2S from natural gas through an electrochemical membrane. H2S is removed from natural gas by reduction to the sulfide ion and H2 at the cathode.
The sulfide ion migrates to the anode through a molten salt electrolyte suspended in an inert ceramic matrix. Once at the anode it is oxidized to elemental sulfur and swept away for condensation in an inert gas stream.
The natural gas is enriched with H2. Order-of-magnitude reductions in H2S concentration have been repeatedly recorded on a single pass through the cell. This process allows removal of H2S, while producing H2 and elemental sulfur directly.
No absorbents are used, and there is no need for subsequent treatment of a concetrated H2S stream as with conventional gas sweetening technology. This makes the process economically attractive, since it is much less equipment-intensive than conventional technology.