Development of a water-selective zeolite composite membrane by a new pore-plugging technique
Résumé
A new membrane preparation method based on mechanical pore-plugging of the supports with appropriate sized seeds followed by secondary zeolite growth by hydrothermal synthesis was optimized for the production of hydroxy-sodalite (hydroxy-SOD) membranes. A series of parameters were investigated during membrane production, including seed loading, presence of Teflon on the coarse side of the support, top-layer orientation in the autoclave, autoclave agitation, synthesis time and temperature, membrane post-synthesis treatment, and nature and pore size of the support (TiO2/SS, SS, Al2O3 and ZrO2/TiO2). Zeolite seeds and synthesized membranes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and gas permeation. The gas permselective separation ability of these membranes was demonstrated from H-2, N-2, CO2 and H2O permeation tests at temperature up to 250 degrees C. The membranes fabricated with the optimized parameters achieved H2O/N-2, H2O/CO2, and H2O/H-2 ideal gas permselectivities of 5.1, 4.8 and 1.4 at 250 degrees C, while providing a high water permeance (Pi(H2O) of 1.26 x 10(-7) mol Pa-1 m(-2) S-1) at the same temperature. (C) 2016 Elsevier Inc. All rights reserved.