The transport of gases in a mesoporous gamma-alumina supported membrane

Gao, Xuechao, Bonilla, Mauricio Rincon, da Costa, Joao C. Diniz and Bhatia, Suresh K. (2013) The transport of gases in a mesoporous gamma-alumina supported membrane. Journal of Membrane Science, 428 357-370. doi:10.1016/j.memsci.2012.10.015

Author Gao, Xuechao
Bonilla, Mauricio Rincon
da Costa, Joao C. Diniz
Bhatia, Suresh K.
Title The transport of gases in a mesoporous gamma-alumina supported membrane
Journal name Journal of Membrane Science   Check publisher's open access policy
ISSN 0376-7388
Publication date 2013-02
Year available 2012
Sub-type Article (original research)
DOI 10.1016/j.memsci.2012.10.015
Volume 428
Start page 357
End page 370
Total pages 14
Place of publication Amsterdam, Netherlands
Publisher Elsevier
Collection year 2013
Language eng
Abstract We investigate the low pressure diffusion of several gases in a disordered mesoporous γ-alumina membrane of pore diameter 10.4. nm, coated on a macroporous α-alumina tubular support. Transport data for the uncoated support is also separately obtained and interpreted using the conventional slip flow correlation with a single representative pore size, and with effective medium theory while considering the entire pore size distribution. It is shown that the conventional correlation based on a single pore size yields significant anomalies in the tortuosity and pressure profile for all gases, which are eliminated on using the effective medium theory, demonstrating the importance of considering the pore size distribution (PSD). These anomalies lead to failure of the correlation for the membrane layer. The effective medium theory is also extended to the disordered membrane layer, using the classical slip flow model and a version corrected for finite molecular size, as well as the Oscillator Model developed in this laboratory. All the diffusion models fitted the experimental data accurately, without the artifacts observed with the commonly used single pore size model. The results make evident the importance of correctly taking the pressure profile into account, in any investigation for a multi-layered supported membrane (i.e. with a macroporous support and a mesoporous membrane layer). It is seen that the slip flow model leads to significantly higher apparent diffusivities than the Oscillator flow model at small pore sizes. Nevertheless, the performance of all three diffusion models is comparable, and it is not possible to distinguish between them for the large pore diameter of 10.4. nm of the mesoporous γ-alumina membrane layer. The results unequivocally show that it is critical to consider the full PSD for each layer rather than using a single representative pore size in modeling membrane transport, and in interpreting experimental permeability data.
Keyword Diffusion in supported membrane
Effective medium theory
Slip flow
Oscillator model
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Available online: 23 October 2012.

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Chemical Engineering Publications
Official 2013 Collection
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 4 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 7 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Sun, 24 Feb 2013, 00:04:56 EST by System User on behalf of School of Chemical Engineering