OXYGEN SEPARATION FROM AIR BY A COMBINED PRESSURE SWING ADSORPTION AND CONTINUOUS MEMBRANE COLUMN PROCESS

The separation of O2 from air, by a process in which the adsorption of N2 on a zeolite is combined with a subsequent O2 enrichment by permea tion through a polymer membrane, was investigated. It was found that a higher degree of O2 separation from air is obtained with the combined pressure swing adsorption (PSA)-continuous membrane column (CMC) proc ess than by either one of the two processes. With its good agreement b etween experimental and the numerically simulated data, the theoretica l model for the CMC process was used to design a PSA-CMC apparatus wit h improved O2 separation. Based on the separation performances and mat erials that are already available, the possibility to develop a PSA-CM C process for the small-scale continuous production of 99.5% O2 from a ir was explored. The results obtained show that the economics of this process compare favorably with those of gaseous O2 supply from high-pr essure cylinders.