The application of transient time-lag method for the diffusion coefficient estimation on zeolite composite membranes

• Published in: Separation and purification technology Vol. 25; no. 1; pp. 467 - 474
• Main Authors: Sanchez, J, Gı̂jiu, C.L, Hynek, V, Muntean, O, Julbe, A
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-10-2001; Elsevier Science
• Subjects: Chemistry; Colloidal state and disperse state; Exact sciences and technology; Gas separation; General and physical chemistry; Kundsen diffusion; Membranes; Time-lag method; Translational diffusion; Zeolite membrane; Translational diffusion; Gas separation; Kundsen diffusion; Time-lag method; Zeolite membrane; Transport properties; Hydrocarbon; Carbon dioxide; Zeolite; Experimental study; Ethane; Composite material; Transient method; Molecular sieve; Time lag; Characterization; Tubular membrane; Hydrothermal synthesis; Preparation; Measurement method; Diffusion coefficient; Alumina; Inorganic membrane
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/S1383-5866(01)00076-4

Time-lag method is a very popular technique which has been developed and widely used for the measurement of diffusion coefficients on polymer membranes. In this work we applied the transient time-lag method for the determination and the modeling of a global diffusion coefficients for CO
2 and C
2H
6 through a composite MFI cylindrical membrane. The developed equations were used for the estimation of global apparent diffusion coefficients which includes the Knudsen like diffusion through intercrystalline holes and the intracrystalline microporous diffusion. The diffusion coefficient was calculated for a previous estimated membrane thickness. This last parameter was obtained from the modeling of steady state permeability at high temperature and for a non-adsorbing gas like helium.