Aqui hay un articulo que da datos sobre las zeolitas:

http://www.pnas.org/cgi/content/full/96/7/3471

Cita:
"Over the last 25 years, improvements in the PSA and VSA O2 processes were driven by the development of zeolite adsorbents with improved N2 capacity and selectivity. Zeolites such as NaX and CaA made possible the development of the first economical PSA O2 process at a relatively small scale [up to approx 15 U.S. tons of O2 per day (tpd)] in the early- to mid-1970s. Second-generation adsorbents, such as CaX (53), and third-generation adsorbents, such as LiX (54), LiCaX or LiSrX (55, 56), and MgA (57), together with improved (vacuum PSA or VSA) processes have dramatically reduced both capital and operating costs. Of the third-generation Type X zeolites, only LiX has been used commercially as of 1997.**"

Las siguientes referencias pueden contener informacion util

Notaro, F. (1996) Sci. Tech. Froid 215-233.
Kumar, R. (1996) Sep. Sci. Technol. 31, 877-893 [ISI].
Armor, J. N. (1995) Adv. Chem. Ser. 245, 321-334 [ISI].
Ruthven, D. M., Farooq, S. & Knaebel, K. S. (1994) Pressure Swing Adsorption (VCH, New York).
Reiss, G. (1994) Gas Sep. Purif. 8, 95-99 [CrossRef][ISI].
Campbell, M. J., Lagree, D. A. & Smolarek, J. (1993) AIChE Symp. Ser. 294, 104-108 .