Patent ID: 6887300
Filing Date: 2005-05-03
Classification: B01D,Y02A

Abstract:
1. A cyclic gas separation process for separating more preferentially permeable gas components from less preferentially permeable gas components of a feed gas mixture of such components, the process comprising the steps of (a) providing a membrane module having a selectively gas permeable membrane for the more preferentially permeable gas components and the less preferentially permeable gas components, (b) simultaneously (i) feeding the feed gas mixture to the module to contact the feed gas mixture with a first side of the membrane, (ii) discharging from the module in fluid communication with a second side of the membrane a permeate gas mixture enriched in the more preferentially permeable gas components, and (iii) withdrawing from the module in fluid communication with the first side of the membrane a retentate gas mixture enriched in the less preferentially permeable gas components, (c) stopping the feeding of the gas feed mixture to the first side, and stopping the withdrawal of retentate gas mixture from the first side, (d) drawing a vacuum in the module effective to remove a portion of a residual gas resident in the module at the time that the feed and withdrawal are stopped, (e) ceasing the drawing of vacuum in the module, and (f) repeating steps (b)-(e).