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Separation of light gas mixtures using SAPO‐34 membranes
Author(s) -
Poshusta Joseph C.,
Tuan Vu A.,
Pape Eric A.,
Noble Richard D.,
Falconer John L.
Publication year - 2000
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690460412
Subject(s) - permeance , selectivity , chemistry , membrane , calcination , adsorption , gas separation , analytical chemistry (journal) , chromatography , porosity , chemical engineering , organic chemistry , catalysis , biochemistry , engineering
Continuous SAPO‐34 membranes were prepared on porous alumina tubular supports, and shown to be useful for light gas separations at low and high temperatures. Single‐gas permeances of CO 2 , N 2 and CH 4 decreased with increasing kinetic diameter. For the best membrane at 300 K, the He and H 2 permeances were less than that of CO 2 , because He, H 2 , and CO 2 were small compared to the SAPO‐34 pore, and differences in the heat of adsorption determined the permeance order. The smaller component permeated the fastest in CO 2 /CH 4 , CO 2 /N 2 , N 2 /CH 4 , H 2 /CH 4 and H 2 /N 2 mixtures between 300 and 470 K. For H 2 /CO 2 mixtures, which were separated by competitive adsorption at room temperature, the larger component permeated faster below 400 K. The CO 2 /CH 4 selectivity at room temperature was 36 and decreased with temperature. The H 2 /CH 4 mixture selectivity was 8 and constant with temperature up to 480 K. Calcination, slow temperature cycles, and exposure to water vapor had no permanent effect on membrane performance, but temperature changes of approximately 30 K/min decreased the membrane's effectiveness.