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A process and apparatus for separating the components of a gas mixture by PSA in a four-vessel adsorption system operated as two pairs of adsorption vessels. The vessels of each pair are operated 180.degree. out of phase, such that one vessel of a pair is in the adsorption mode while the other vesse

A process and apparatus for separating the components of a gas mixture by PSA in a four-vessel adsorption system operated as two pairs of adsorption vessels. The vessels of each pair are operated 180.degree. out of phase, such that one vessel of a pair is in the adsorption mode while the other vessel of the pair is undergoing adsorbent regeneration. The apparatus includes the two pairs of adsorption vessels, an intermediate gas storage reservoir which is used to temporarily store gas removed from the nonadsorbed gas outlet end of the adsorption vessels for use in various steps of the process, one gas blower and a pair of vacuum pumps. The adsorption cycle is such that the pairs of adsorption vessels are operated out of phase relative to each other and the blower and both vacuum pumps are in continuous operation throughout the process. The process and system are particularly well adapted to the separation of nitrogen from oxygen by vacuum swing adsorption.

대표청구항 ▼

[ What is claimed is:] [1.] A pressure swing adsorption process for producing first component-enriched gas from a gas mixture containing first and second components in a system comprising four adsorption zones each containing an adsorbent which selectively adsorbs said second component, a first gas

[ What is claimed is:] [1.] A pressure swing adsorption process for producing first component-enriched gas from a gas mixture containing first and second components in a system comprising four adsorption zones each containing an adsorbent which selectively adsorbs said second component, a first gas pumping means, and at least one second gas pumping means, comprising repeatedly performing in each adsorption zone the following sequence of steps:(i) producing first component-enriched gas by cocurrently introducing said gas mixture into said adsorption zone at a selected adsorption pressure and cocurrently removing first component-enriched gas therefrom;(ii) partially depressurizing said adsorption zone by cocurrently removing partially fractionated gas therefrom;(iii) further depressurizing said adsorption vessel by countercurrently withdrawing second component-enriched gas therefrom;(iv) further depressurizing said adsorption vessel by countercurrently withdrawing second component-enriched gas therefrom;(v) purging said adsorption zone by introducing (a) first component-enriched gas, (b) partially fractionated gas or (c) combinations of these countercurrently thereinto while countercurrently withdrawing gas therefrom; and(vi) at least partially repressurizing said adsorption vessel by introducing: (a) first component-enriched gas countercurrently thereinto, (b) partially fractionated gas countercurrently thereinto (c) said gas mixture cocurrently thereinto, or (d) by combinations of two or more of (a), (b) and (c); said first gas pumping means being used exclusively for steps (i) and (iii) in all adsorption vessels and said at least one second gas pumping means being used exclusively for steps (iv) and (v) in all vessels.