Laminated zeolite composite and method for production thereof

Abstract

A laminated zeolite composite is provided, including a MFI membrane constituted by a MFI type zeolite having a SiO 2 /Al 2 O 3 (molar ratio) of 40 to 100, and a porous substrate constituted by a MFI type zeolite having a SiO 2 /Al 2 O 3 (molar ratio) of 20 to 400, wherein the MFI membrane is formed on the porous substrate. The composite has high separation characteristics and high permeability.

1 . A method for producing a laminated zeolite composite comprising immersing a porous substrate in a silica sol-containing sol for membrane formation and forming a MFI membrane on the porous substrate under heating conditions; 
 said method being characterized in that a porous substrate being constituted by a MFI type zeolite and having a SiO 2 /Al 2 O 3  (molar ratio) of 20 to 400 is immersed in a sol for membrane formation having a SiO 2 /Al 2 O 3  (molar ratio) of 40 to 150 and a Na 2 O/Al 2 O 3  (molar ratio) of 15 or less.    
   
   
       2 . A method for producing a laminated zeolite composite according to  claim 1 , wherein a MFI membrane being constituted by a MFI type zeolite and having a SiO 2 /Al 2 O 3  (molar ratio) of 40 to 100 is formed.