US 8,262,779 B2 · Microporous aluminophosphate molecular sieve membranes for highly selective separations

Abstract

The present invention discloses microporous aluminophosphate (AlPO4) molecular sieve membranes and methods for making and using the same. The microporous AlPO4 molecular sieve membranes, particularly small pore microporous AlPO-14 and AlPO-18 molecular sieve membranes, are prepared by three different methods, including in-situ crystallization of a layer of AlPO4 molecular sieve crystals on a porous membrane support, coating a layer of polymer-bound AlPO4 molecular sieve crystals on a porous membrane support, and a seeding method by in-situ crystallization of a continuous second layer of AlPO4 molecular sieve crystals on a seed layer of AlPO4 molecular sieve crystals supported on a porous membrane support. The microporous AlPO4 molecular sieve membranes have superior thermal and chemical stability, good erosion resistance, high CO2 plasticization resistance, and significantly improved selectivity over polymer membranes for gas and liquid separations, including carbon dioxide/methane (CO2/CH4), carbon dioxide/nitrogen (CO2/N2), and hydrogen/methane (H2/CH4) separations.

Claims6

Dependent claims

A method of making a microporous crystalline aluminophosphate (AlPO4) 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 AlPO4 molecular sieve crystal particles synthesized by a hydrothermal synthesis method;
c) dispersing the template-free AlPO4 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 AlPO4 molecular sieve particles in the slurry to form a stable polymer-bound AlPO4 molecular sieve suspension wherein said template-free AlPO4 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 AlPO4 molecular sieve suspension;
and
f) drying the coated porous membrane support by applying heat to form a microporous AlPO4 molecular sieve membrane.

4 more elements

Dependencies are inferred from the claim text.

Microporous aluminophosphate molecular sieve membranes for highly selective separations

Life of this patent

Microporous aluminophosphate molecular sieve membranes for highly selective separations

Life of this patent

Abstract

Claims6