Title of article :
Adsorption and diffusion properties of zeolite membranes by transient permeation Original Research Article
Author/Authors :
Tracy Q. Gardner، نويسنده , , John L. Falconer، نويسنده , , Richard D. Noble، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2002
Pages :
6
From page :
435
To page :
440
Abstract :
Adsorption isotherms and diffusion coefficients for light gases and butane isomers were measured for the transport pathways involved in gas permeation through H-ZSM-5 membranes by a transient permeation technique. The permeate responses to step changes in the feed were measured, and the transport was modeled as Maxwell—Stefan diffusion with single-site Langmuir adsorption in the zeolite. Isotherms measured for N2, CO2, and CH4 at 295 K were nearly identical to those measured by calorimetry on H-ZSM-5 powders. Isotherms for butane isomers were also similar to isotherms for MFI powders and heats of adsorption and diffusion activation energies were in the ranges reported in the literature. Maxwell—Stefan diffusion coefficients for all gases studied increased slightly with feed partial pressure and were similar to those measured by other macroscopic methods for zeolite membranes and crystals. Effective membrane thicknesses were also determined non-destructively for tubular zeolite membranes by the transient permeation technique.
Keywords :
Adsorption isotherms , Transport modeling , Maxwell—Stefan diffusion , Transient permeation , Zeolite membranes
Journal title :
Desalination
Serial Year :
2002
Journal title :
Desalination
Record number :
1108015
Link To Document :
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