An initial investigation of a nano-composite silica ceramic membrane for hydrogen gas separation and purification

摘要

The effects of trans-membrane pressure difference on hydrogen recovery are investigated on a preliminary basis. The membrane has been developed for high temperature hydrogen separation from CH4, N-2, and Ar gas molecules. Gas permeation and separation performance of the developed membrane was evaluated. The silica fabricated membrane exhibited high H-2 gas flux and much lower fluxes for CH4, N-2, and Ar and showed a rise in permeance with the inverse of the square root of temperature for H-2. Plots obtained with respect to the effects of gauge pressure on H-2, N-2, CH4 and Ar component gas fluxes through the modified support (silica membrane) at a pressure of 1 bar showed that H-2 recorded an almost four-fold high flux value of 0.76 mol/m(2).s compared to that of 0.33 mol/m(2).s (CH4), 0.25 mol/m(2).s (N-2) and 0.22 mol/m(2).s (Ar). These results were nearly stable for the temperature range investigated (298 K, 373 K and 473 K). In addition, hydrogen maintained a relatively high permeance value of 1.62 x 10(-5) mol m(-2) s(-1) Pa-1 at a low pressure of 0.1 bar under room temperature (298 K) compared to that of N-2, CH4 and Ar which were much lower throughout the temperature range studied and in agreement with literature. H-2 separation factor (experimental Knudsen) over CH4, N-2 and Ar were quite close to the theoretical Knudsen and can therefore be experimentally applied through further optimization in the separation of H-2 as a key constituent energy for the future. (C) 2015 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.