2008 Volume 33 Issue 3 Pages 713-716
Y -type zeolite membranes containing Na+ ions were synthesized on the outer surface of a porous a-alumina support tube by means of a hydrothermal reaction. The Na+ ions of the membranes were ion-exchanged with Sr2+ ions, and the separation properties of the membranes were investigated at 313 K for mixtures of N2 and O2. Although the exchange of Na+ ions with Sr2+ ions greatly increased the N2 adsorption capacity, the SrY-type zeolite membranes had oxygen over nitrogen selectivities (up to 2.1) and O2 permeances of the order of 10-9 mol m-2 s-1 Pa-1. Those findings suggest that N2 permeability was hindered by the Sr cations present that would interact strongly with N2, resulting in an increased O2 permeability, compared to N2.
