摘要 |
Multicomponent gas mixtures containing (1) hydrogen as a primary component, (2) a secondary key component that is more strongly sorbed by the adsorbent than hydrogen and (3) a minor quantity of one or more dilute components less strongly sorbed than the secondary key component, are subjected to selective adsorption in an integrated adiabatic pressure swing adsorption (PSA) system having three groups of adsorbent columns interconnected for controlled series gas flow from a selected column of one group to a selected column of another group. In the disclosed example, directed to treatment of a shift converter effluent from a hydrocarbon reforming plant, contained carbon dioxide is selectively adsorbed in and recovered from a column of the first group. The minor dilute components (such as CH4 and/or CO) are retained by adsorption in a column of the second group, thus permitting recovery therefrom of unsorbed high purity hydrogen. By depressurizing and purging of the impurity-laden column of the second group with high purity hydrogen, an effluent stream is obtained, comprised of hydrogen and desorbed minor components. This stream is passed through a column of the third group wherein the contained minor components are sorbed and a further amount of high purity hydrogen is recovered as effluent.
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