effect of dehydration temperature on the h2 separation potential of hydroxy sodalite zeolite membranes

the main goal of this work was to synthesize and evaluate the effect of dehydration temperature on the potential application of hydroxy sodalite zeolite membrane. hydroxy sodalite zeolite membranes were synthesized via direct hydrothermal method onto a tubular alumina support without seeding in a hot air oven. the synthesized membranes were characterized by x-ray diffraction (xrd) and scanning electron microscopy (sem). permeation tests of h2 and co2 were carried out in order to investige the applied dehydration temperature effect on the performance of the synthesized membranes. the performance of the synthesized membrane dehydrated at 100 ºc tended to high selectivity compared to that of the rest samples and the maximum separation factor (~21) was achieved with acceptable permeances about 3.810-8 and 1.8*10-9 mol.m-2.pa-1.s-1 for h2 and co2, respectively. the low selectivities observed for two other synthesized membranes (dehydrated at 150 and 200 ºc), indicating the formation of defects during the dehydration of these membranes at high temperatures.