Patent ID: 8043988

Claim:
A process for preparation of FAU-structural type supported membranes that comprises the following stages: stage a) preparation of a precursor of a FAU-structural type zeolite, said precursor being a gel precursor or a gel-suspension precursor, said precursor comprising at least one framework silicon source, at least one source of another framework element, at least one mineralizing agent, and at least one structuring organic compound, in which the molar composition of the gel or gel-suspension precursor is as follows: 1 SiO 2 —w another framework element—x H 2 O—y Na 2 O=z structuring-organic-compound w, x, y and z that respectively represent molar ratios of: another-framework-element/silica, water/silica, soda/silica structuring-organic-compound/silica, whereby w is between 0 and 0.5, inclusive x is between 5 and 1000, inclusive y is between 0 and 80, inclusive z is between 0 and 5, inclusive in which, before gelling, the gel precursor or the gel suspension precursor is provided in clear, liquid form, in which the precursor is prepared at a temperature of not more than 5° C., stage b) bringing the precursor of stage a) into contact, prior to gelling with a porous substrate by complete immersion of said porous substrate in the precursor before gelling, whereby this stage is carried out at −7 to 15° C. for a time sufficient to cause gelling of the precursor, stage c) bringing the resultant substrate obtained at the end of stage b) into contact with a precursor of an FAU-structural type zeolite, said precursor being a gel precursor, a gel-suspension precursor, or a clear solution, complying with said values of w, x, y and z, said precursor of stage (c) being the same or different from the precursor brought into contact with the substrate during stage b), stage c′) ageing of resultant impregnated substrate obtained at the end of stage c) at a temperature of between −20 and 50° C., stage d) subjecting the substrate that is obtained at the end of stage c), to hydrothermal treatment in an autoclave with stirring of the precursor and/or the substrate at a temperature of between 85° C. and 100° C. for a sufficient time at said temperature to obtain a zeolite.