The raw gas for variable pressure adsorption contains H2S, which needs to be removed if it is greater than 20 ppm, taking into account the life of the adsorbent and the quality of the product. the removal of H2S can be done by a dry desulphurisation process using a fixed bed with a room temperature iron oxide desulphurising agent inside. Desulphurisation towers can usually be set up as two or more,...