Process for producing zeolite separation membrane
View Patent ↗A process for producing a zeolite separation membrane having a porous support containing alumina as a main component and, provided on a surface and within pores of the porous support, a zeolite layer, comprising the seed crystal adhering step of adhering USY zeolite crystal as a seed crystal on a surface and within pores of the porous support; the basis material forming step of bringing a reactant liquid containing silicon and aluminum into contact with the porous support and heating the reactant liquid to thereby obtain a zeolite separation membrane basis material; and the basis material separating step of separating the zeolite separation membrane basis material from the reactant liquid to thereby obtain a zeolite separation membrane. By this process for producing a zeolite separation membrane, there can be produced an FAU zeolite separation membrane capable of satisfactory separation of a mixture of organic solvent and water.
1. A process for production of a faujasite (FAU) zeolite separation membrane having a porous support and a zeolite layer formed on the surface of, and inside the pores of, the porous support, wherein the porous support has an alumina content of at least 90% with respect to the total weight of the porous support, the process comprising:
a seed crystal-attaching step in which USY zeolite crystals are attached as seed crystals to the surface of, and inside the pores of, the porous support;
a crude product-forming step in which: the porous support is contacted with a reaction solution containing silicon and aluminum at a molar ratio of silicon to aluminum (Si/Al) of 1.8 to 12.5, and the reaction solution is heated to form a crude product of the zeolite separation membrane; and
a crude product-separating step in which the crude product of the zeolite separation membrane is separated from the reaction solution to afford the FAU zeolite separation membrane.
2. The process for production of an FAU zeolite separation membrane according to claim 1 , wherein the alumina is selected from the group consisting of α-alumina, β-alumina and γ-alumina.
3. The process for production of an FAU zeolite separation membrane according to claim 1 , wherein the mean pore size of the porous support is 0.1 to 20μm.
4. The process for production of an FAU zeolite separation membrane according to claim 1 , wherein the porosity of the porous support is 5% to 50%.
5. The process for production of an FAU zeolite separation membrane according to claim 1 , wherein a seed crystal slurry containing 0.01% to 20% by weight of USY crystals is contacted with the porous support in the seed crystal-attaching step.
6. The process for production of an FAU zeolite separation membrane according to claim 1 , wherein the total amount of silica source and alumina source in the reaction solution is 50% to 99.5% by weight with respect to the total weight of the reaction solution.
7. The process for production of an FAU zeolite separation membrane according to claim 1 , wherein the reaction solution is heated to higher than 40° C. in the crude product-forming step.
8. The process for production of an FAU zeolite separation membrane according to claim 1 , wherein the crystals of FAU zeolite of the obtained FAU zeolite separation membrane are Y-type zeolite crystals.
9. A method of separating a liquid mixture, comprising the steps of:
providing an FAU zeolite separation membrane produced by the process for production of an FAU zeolite separation membrane according to claim 1 ; and
separating the liquid mixture with the FAU zeolite separation membrane.