Process for the preparation of porous glass supported zeolite membranes and zeolite membranes obtained thereby

摘要

The preparation of a composite containing a continuous zeolite layer located essentially at the surface of a porous glass support is claimed. It involves several steps: (a) partial hydrolysis of internal and external surfaces of the silica of the glass porous support of pores of diameter 2-10 nm and total pore volume fraction greater than 25%, reaction carried out by contacting the support with pure water at temperature between 20-250 degrees C. during 1 hour-8 days; (b) drying of the hydrolysed support at a temperature less than 120 degrees C., then contacting with a sol or gel containing one or several elements of the framework and additives for zeolite crystallisation; (c) crystallising the zeolite by heating the support immersed in the solution at a temperature between 100-130 degrees C. during 3 hours-15 days, to obtain the membrane; (d) cooling of the resulting membrane, washing with distilled water to eliminate at least partially one or several elements of the framework, and/or additives of zeolite crystallisation, then drying by heating progressively at a calcination temperature of 300-800 degrees C. and maintaining the membrane at this temperature between 10 minutes and 24 hours; (e) separating of the support from the sol or gel, contacting it with saturated water vapour between 3 hours and 3 days, then cooling down to ambient temperature in between 1-24 hours.