Patent ID: 8262779

Claim:
A method of making a microporous crystalline aluminophosphate (AlPO 4 ) molecular sieve membrane, comprising the steps of: a) providing a porous membrane support having an average pore size of 0.1 μm or greater than 0.1 μm; b) providing template-free AlPO 4 molecular sieve crystal particles synthesized by a hydrothermal synthesis method; c) dispersing the template-free AlPO 4 molecular sieve crystal particles in at least one solvent to form a slurry; d) dissolving one or two types of polymers as a binder of the template-free AlPO 4 molecular sieve particles in the slurry to form a stable polymer-bound AlPO 4 molecular sieve suspension wherein said template-free AlPO 4 molecular sieve particles to said one or two types of polymers are present at a volume ratio of about 70:30 to 99:1; e) coating at least one surface of the porous membrane support with the stable polymer-bound AlPO 4 molecular sieve suspension; and f) drying the coated porous membrane support by applying heat to form a microporous AlPO 4 molecular sieve membrane.