Patent ID: 11931698
Assignee: UOP LLC
Field: Chemical engineering (Chemistry)
Classification: CPC B  C  Y | IPC B  C

Claim 0:
1. A method of making a thin film composite gas separation membrane, for separating at least hydrogen sulfide from a mixture of gases, comprising a polyether block amide copolymer coating layer and a nanoporous asymmetric polyacrylonitrile support membrane with nanopores on a skin layer surface of the support membrane and gelatin polymers inside nanopores on the skin layer surface of the support membrane comprising:
a) casting a membrane casting dope to form a wet nanoporous asymmetric flat sheet or hollow fiber support membrane via a phase inversion membrane casting or spinning fabrication process;
b) nipping an aqueous solution of gelatin with a concentration in a range of 0.01 wt % to 0.05 wt % at the end of the membrane casting fabrication process during the membrane casting fabrication process to incorporate gelatin polymers into the nanopores on the skin layer surface of the nanoporous asymmetric polyacrylonitrile support membrane;
c) drying the wet nanoporous asymmetric polyacrylonitrile flat sheet support membrane with gelatin inside the nanopores on the skin layer surface of the support membrane through a direct air drying method or through a solvent exchange method to form a dried nanoporous asymmetric polyacrylonitrile support membrane with gelatin inside the nanopores on the skin layer surface of the support membrane;
d) coating a thin, nonporous, polyether block amide copolymer layer on the skin layer surface of the dried nanoporous asymmetric polyacrylonitrile support membrane via using a solution of the polyether block amide copolymer comprising about 0.2 to about 5 wt % of polyether block amide copolymer and an alcohol solvent or a solvent mixture of an alcohol and water; and
e) drying the polyether block amide copolymer coated nanoporous asymmetric polyacrylonitrile support membrane at about 50 to 100° C. to form the thin film composite gas separation membrane.