Method to make carbon molecular sieve hollow fiber membranes
AssigneeDow Global Technologies LLC
InventorsLiren Xu, Rahul Sharma, Thomas Fitzgibbons, Mark K. Brayden, Marcos V. Martinez
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Abstract
A method of making a hollow fiber carbon molecular sieve is comprised of heating a hollow polymer fiber to a carbonization temperature in an atmosphere that is non-oxidizing to form a hollow fiber carbon molecular sieve, wherein during at least a portion of the heating a tensile force is applied to the hollow polymer fiber. The method may improve the separation of gases similar in size such a propylene from propane.
Claims16
A method of making a hollow fiber carbon molecular sieve membrane comprising,
- (i) providing a hollow polymer fiber comprised of a polyimide, wherein the polyimide is the reaction product of a dianhydride and a diamine, and wherein the dianhydride is comprised of an aromatic dianhydride that has no rotational freedom within the dianhydride,
- (ii) heating the hollow polymer fiber to a carbonization temperature in an atmosphere that is non-oxidizing to form a hollow fiber carbon molecular sieve, wherein during at least a portion of the heating a tensile force is applied to the hollow polymer fiber along a length of the hollow polymer fiber to form the hollow fiber carbon molecular sieve membrane.
A method of making a hollow fiber carbon molecular sieve membrane comprising,
- (i) providing a hollow polymer fiber comprised of a polyimide,
- (ii) heating the hollow fiber polymer to a carbonization temperature in an atmosphere that is non-oxidizing to form a hollow fiber carbon molecular sieve, wherein during at least a portion of the heating a tensile force is applied to the hollow fiber along a length of the hollow polymer fiber to form the hollow fiber carbon molecular sieve membrane,
- wherein the polyimide is represented by:
- where X is 0.1 to 0.9 and Y is 0.1 to 0.9 and X+Y=1 and n is an integer that may be any that realizes a molecular weight of 30 to 200 kDa.
Dependencies are inferred from the claim text.