Dehydration of water/UDMH mixtures by hydroxysodalite zeolite membranes

Effects of synthesis parameters on the membrane structure and performance have been investigated for HS zeolite membranes grown onto seeded mullite supports. Molar composition of the starting gel of HS zeolite membranes was: SiO2/Al2O3=1.0-5.0, Na2O/Al2O3=15-65, and H2O/Al2O3=500-1500. X-ray diffraction (XRD) patterns of the membranes exhibited peaks corresponding to the support and the zeolite. The crystal species were characterized by XRD and morphology of the supports subjected to crystallization was characterized by Scanning electron microscopy (SEM). Separation performance of HS zeolite membranes was studied for water-unsymmetrical dimethylhydrazine (UDMH) mixtures using pervaporation (PV). The membranes showed good selectivity towards water in the water-UDMH mixtures. Water permeates faster because of its preferential adsorption into the nano-pores of the hydrophilic zeolite membrane. In PV of water-UDMH mixtures, the membrane exhibits a hydrophilic behavior, with a high selectivity towards water and a good flux. The best Flux and separation factor of the membranes were 1.44 kg/m2.h and 52000, respectively.

Dehydration of water/UDMH mixtures by hydroxysodalite zeolite membranes Keywords:

hydroxysodalite , Pervaporation , Zeolite membrane , UDMH , synthesis parameters