Preparation of Nano pore Faujasite Zeolite Membranes and their pervaporation performance for UDMH mixtures

فاقد چكيده

Nano pore Faujasite zeolite membranes were synthesized by in-situ hydrothermal method on porous ceramic tubes. Hydrothermal crystallization was carried out under an autogenously pressure and at a static condition of 100 oC. Molar composition of the starting gel of Faujasite zeolite membranes were NaX: SiO2/Al2O3=10-27, Na2O/Al2O3=4-9, H2O/Al2O3=250; NaY: SiO2/Al2O3=2.5-4, Na2O/SiO2=1.08-2, H2O/Na2O=30-200. The crystal species were characterized by X-ray diffraction (XRD) and morphology of the supports subjected to crystallization was characterized by Scanning electron microscopy (SEM). Separation performance of Faujasite (NaX, NaY) zeolite membranes was studied for water-unsymmetrical dimethylhydrazine (UDMH) mixtures using pervaporation (PV). 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 membranes had a water flux of 2.22 and 2.67 kg/m2.h at 27 oC for NaY and NaX respectively. The best PV selectivity was obtained to be 72 and 40 for NaY and NaX respectively.