Patent ID: 8685143

Claim:
A method of making a supported gas separation molecular sieve membrane, wherein said method comprises: applying molecular sieve crystals to a surface of a porous support to thereby provide a seeded porous support surface; contacting under hydrothermal synthesis conditions said seeded porous support surface with a synthesis gel mixture for a shortened crystallization time in the range of less than 15 hours so as to provide a coated porous support, wherein said synthesis gel comprises: an aluminum source, a phosphorus source, a silicon source, a quaternary ammonium templating agent (R), and water in amounts such that the composition of said synthesis gel has the following molar ratios: 1Al 2 O 3 :a P 2 O 5 :b SiO 2 :c R: d H 2 O; wherein: a is from 0.01 to 52; b is from 0.03 to 196; c is from 0.2 to 5; and d is from 20 to 300; and calcining said coated porous support under calcination conditions including a calcination temperature in the range of from 250Â° C. to 650Â° C. to thereby provide said supported gas separation molecular sieve membrane that is characterized as having a CO 2 /CH 4 separation selectivity (based on a pressure driving force of 138 kPa and a temperature of 22Â° C.) of at least 100.