Patent ID: 8753425

Claim:
A method of preparing a supported gas separation membrane, wherein the method comprises: a. preparing SAPO-34 crystalline seeds from a synthesis mixture comprising an aluminum source, a phosphorous source, a silicon source, at least one organic templating agent and water; b. applying the SAPO-34 crystalline seeds to a porous support to produce a seeded porous support; c. contacting the seeded porous support with a synthesis gel under hydrothermal synthesis conditions to produce a coated porous support; and d. calcining the coated porous support to provide the supported gas separation membrane with a molecular sieve membrane layer; wherein the molar ratio of water to Al 2 O 3 of the synthesis gel in step (c) is greater than the molar ratio of water to Al 2 O 3 of the synthesis mixture of step (a), and wherein the molar ratio of water to Al 2 O 3 in step (c) is at least 150:1.