Innovative methods for preparation and testing of Al2O3 supported silicalite-1 membranes

• Published in: Journal of the European Ceramic Society 2001-02, Vol.21 (2), p.119-126
• Main Authors: ROMANOS, G. E, STERIOTIS, Th. A, KIKKINIDES, E. S, KANELLOPOULOS, N. K, KASSELOURI, V, RAMSAY, J. D. F, LANGLOIS, P, KALLUS, S
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Membranes
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/S0955-2219(00)00176-X

Inorganic membranes formed from a coherently grown layer of zeolite crystals offer substantially higher permeabilities and selectivities compared with polymeric materials and can perform under extreme conditions, e.g. at elevated temperatures and in aggressive chemical environments. Such membranes are prepared by in-situ hydrothermal synthesis of a zeolite layer within the macropores of alumina ceramic supports (tubes/discs). In this way, more stable zeolite membranes are produced, avoiding outer separating layers which are prone to mechanical damage. These membranes have also been shown to have good thermal stability up to 500C, with no evidence of crack formation. The synthesised materials were characterised by several techniques such as Hg and N2 porosimetry, SEM, and XRD. From these measurements it appears that the structure of the zeolite membrane is influenced by several factors, such as structure and size of the pores of the support, chemical composition of the precursor solution, reaction conditions, etc. Finally, gas permeabilities and/or selectivities were measured for several important gas systems. Results indicate the important role of influencing the outcome of the crystal formation by controlling the conditions of the hydrothermal treatment in obtaining optimum gas permeabilities and/or selectivities of these systems. 17 refs.