Two-feed pressure swing adsorption process for enhancing the recovery of hydrogen in a feed gas

摘要

The invention deals with a two-feed pressure swing adsorption process for enhancing the recovery of hydrogen in a feed gas. …??One portion comprising about 30-80% of a hydrogen-containing feed gas having a relatively high carbon dioxide content is preheated to remove a substantial portion of said carbon dioxide therefrom. The thus-preheated stream is passed to a pressure swing adsorption bed from which a purified hydrogen stream is withdrawn. Upon completion of this step, the unpretreated portion of the feed gas is passed to the feed end of the bed, with purified hydrogen continuing to be withdrawn from the bed. In cyclic pressure swing adsorption operations employing such a two-feed process, the recovery of purified hydrogen is enhanced as compared with operations in which none of the feed gas is pretreated for carbon dioxide removal or in which all of the feed gas is so treated for removal of carbon dioxide therefrom.