Ceramic membranes Vycor glass

Most porous membranes used in CMRs are made from oxide materials, although carbon membranes have also been used [1, 14, 22], However, although they possess very good separative properties, they have received less attention in CMR applications, probably due to their limited resistance to oxidative atmospheres. Vycor glass membranes also have certain drawbacks (brittleness, lack of high-temperature resistance) [9] for use in CMRs. Porous membranes in CMRs are, most often, made from ceramic materials or, more recently, from zeolites. 

Shown in Table 9.7 are some examples of incorporating catalysts into porous ceramic membranes. Both metal and oxide catalysts have been introduced to a variety of ceramic membranes (e.g., alumina, silica, Vycor glass and titania) to make them catalytically active. The impregnation/heat U eatment procedures do not appear to show a consistent cause-and-effeci relationship with the resulting membrane permeability. For example, no noticeable change is observed when platinum is impregnated into porous Vycor glass... 

Harold M.P., Cini P, Patenaude B. and Venkataraman K., The catalytically impregnated ceramic tube An alternative multiphase reactor, AIChE Symposium Series 85 (265) 26 (1989). Song J.Y. and Hwang S.-T, Formaldehyde production from methanol using a porous Vycor glass membrane. Proceedings of ICOM 90, Chicago, (30)540 (1990). 

Porous membranes are usually characterized by mesopores, with transport in the Knudsen regime. Typical examples are Vycor glass and Y-AI2O3. Thin-film ceramic membranes also belong to this category... 

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