Adsorption process for the separation of gaseous mixtures

A selective adsorption process for the separation of gaseous mixtures comprising the steps of:

• (a) passing a feed gas mixture containing components A and B successively at a first pressure through two adsorption beds selective for component A until the evolving adsorption front of component A substantially reaches the outflow end of the first adsorption bed or has only unsubstantially penetrated into the second adsorption bed, discharging an A-free product gas from the outflow end of the second adsorption bed, then interrupting the feeding of the feed gas mixture to the first adsorption bed;
• (b) expanding both adsorption beds in the adsorption direction to a lower pressure sufficient so that proportions of unadsorbed component A emerge from said first adsorption bed, and so that said emerged proportions from the first adsorption bed are adsorbed in the second adsorption bed, and withdrawing an A-free gas from the second adsorption bed;
• (c) at the same pressure as in step (b), conducting a further gaseous mixture in the adsorption direction through both adsorption beds, the partial pressure of component A in said further gaseous mixture being higher than in the feed gas;
• interrupting the feeding of said further gaseous mixture before the breakthrough of component A through the second adsorption bed, and withdrawing an A-free gas from said second adsorption bed;
• (d) disconnecting both adsorption beds from one another, and expanding the first adsorption bed loaded substantially completely with component A to recover component A;
• and at the same time expanding the second adsorption bed, partially loaded with component A, in a countercurrent direction to the adsorption process and passing a purge gas in said countercurrent direction through the expanded second adsorption bed to desorb component A;
• and
• (e) reconnecting both adsorption beds with each other and charging same to said first pressure of step (a).