Feasibility study on pressure swing sorption for removing H2S from natural gas

The possibility of removing H₂S from natural gas by applying a pressure swing sorption (PSS) process was experimentally proven. The key technique of the PSS process relies on using a special type of sorbent where solid grains were coated by a layer of liquid. It was shown that the solubility of H₂S in the layer of liquid enlarged the concentration of H₂S at the solid surface and, hence enhanced the adsorption of H₂S on adsorbent. The solubility of H₂S is very sensitive to the partial pressure above the layer of liquid, therefore, the saturated sorbent could be easily regenerated by sweeping the bed of sorbent with nitrogen at ambient temperature and pressure. The sorption capacity as well as the coated sorbent was stable during the operation cycles of sorption/desorption. The new PSS technology of sweetening natural gas is advantageous over the prevailing technologies of today in that both savings of investment and energy cost could be expected.