Membranes for gas separation
Membranes, methods of making the membranes, and methods of using the membranes are described. The membranes can comprise a support layer, and a selective polymer layer disposed on the support layer. The selective polymer layer can comprise an oxidatively stable carrier dispersed within a hydrophilic polymer matrix. The oxidatively stable carrier can be chosen from a quaternary ammonium hydroxide carrier (e.g., a mobile carrier such as a small molecule quaternary ammonium hydroxide, or a fixed carrier such as a quaternary ammonium hydroxide-containing polymer), a quaternary ammonium fluoride carrier (e.g., a mobile carrier such as a small molecule quaternary ammonium fluoride, or a fixed carrier such as a quaternary ammonium fluoride-containing polymer), and combinations thereof. The membranes can exhibit selective permeability to gases. The membranes can selectively remove carbon dioxide and/or hydrogen sulfide from hydrogen and/or nitrogen. Further, the membranes can exhibit oxidative stability at temperatures above 100° C.
1. A membrane comprising:
a support layer; and
a selective polymer layer disposed on the support layer, the selective polymer layer comprising an oxidatively stable carrier dispersed within a hydrophilic polymer matrix,
wherein the oxidatively stable carrier is selected from the group consisting of a quaternary ammonium hydroxide-containing polymer, a quaternary ammonium fluoride-containing polymer, and combinations thereof.
2. The membrane of claim 1 , wherein the oxidatively stable carrier comprises a quaternary ammonium hydroxide-containing polymer.
3. The membrane of claim 2 , wherein the quaternary ammonium hydroxide-containing polymer is selected from the group consisting of poly(diallyldimethyl-ammonium hydroxide), poly(vinylbenzyltrimethylammonium hydroxide), poly(2-vinyl-1-methylpyridinium hydroxide), poly(acrylamide-N-propyltrimethylammonium hydroxide), poly(2-methacryloxyethyltrimethylammonium hydroxide), poly(3-chloro-2-hydroxypropyl-2-methacryloxyethyldimethylammonium hydroxide), copolymers thereof, and blends thereof.
4. The membrane of claim 1 , wherein the oxidatively stable carrier comprises a quaternary ammonium fluoride-containing polymer.
5. The membrane of claim 4 , wherein the quaternary ammonium fluoride-containing polymer is selected from the group consisting of poly(diallyldimethyl-ammonium fluoride), poly(vinylbenzyltrimethylammonium fluoride), poly(2-vinyl-1-methylpyridinium fluoride), poly(acrylamide-N-propyltrimethylammonium fluoride, poly(2-methacryloxyethyltrimethylammonium fluoride), poly(3-chloro-2-hydroxypropyl-2-methacryloxyethyldimethylammonium fluoride), copolymers thereof, and blends thereof.
6. The membrane of claim 1 , wherein the hydrophilic polymer matrix comprises a crosslinked hydrophilic polymer.
7. The membrane of claim 1 , wherein the hydrophilic polymer matrix comprises polyvinyl alcohol.
8. The membrane of claim 1 , wherein the hydrophilic polymer matrix comprises polyvinyl alcohol-polysiloxane.
9. The membrane of claim 1 , wherein the support layer comprises a gas permeable polymer.
10. The membrane of claim 9 , wherein the gas permeable polymer comprises a polymer selected from the group consisting of polyamides, polyimides, polypyrrolones, polyesters, sulfone-based polymers, polymeric organosilicones, fluorinated polymers, polyolefins, copolymers thereof, and blends thereof.
11. The membrane of claim 10 , wherein the gas permeable polymer comprises polyethersulfone or polysulfone.
12. The membrane of claim 1 , wherein the support layer comprises a gas permeable polymer disposed on a base.
13. The membrane of claim 12 , wherein the base comprises a non-woven fabric.
14. The membrane of claim 13 , wherein the non-woven fabric comprises fibers formed from a polyester.
15. The membrane of claim 1 , wherein the membrane further comprises a permeable layer disposed between the support layer and the selective polymer layer.
16. The membrane of claim 15 , wherein the permeable layer comprises a gas permeable polymer is selected from the group consisting of poly(dimethylsiloxane), poly(trimethylsilylpropyne), poly(4-methyl-1-pentene), copolymers thereof, and blends thereof.
17. The membrane of claim 1 , wherein the membrane further comprises a permeable layer disposed on the selective polymer layer.
18. The membrane of claim 17 , wherein the permeable layer comprises a gas permeable polymer is selected from the group consisting of poly(dimethylsiloxane), poly(trimethylsilylpropyne), poly(4-methyl-1-pentene), copolymers thereof, and blends thereof.
19. The membrane of claim 1 , wherein the membrane is configured in a flat sheet, a spiral-wound, a hollow fiber, or a plate-and-frame configuration.
20. A method for separating a first gas from a feed gas stream, the method comprising contacting a membrane defined by claim 1 with the feed gas stream comprising the first gas under conditions effective to afford transmembrane permeation of the first gas.
21. The method of claim 20 , wherein the feed gas comprises hydrogen, carbon dioxide, hydrogen sulfide, hydrogen chloride, carbon monoxide, nitrogen, methane, steam, sulphur oxides, nitrogen oxides, or combinations thereof.
22. The method of claim 21 , wherein the first gas is chosen from carbon dioxide, hydrogen sulfide, hydrogen chloride, and combinations thereof.
23. The method of claim 20 , wherein the first gas exhibits a permeance of at least 50 GPU at 120° C.
24. The method of claim 23 , wherein the first gas exhibits a permeance of from 50 GPU to 500 GPU at 120° C.
25. The method of claim 24 , wherein the first gas exhibits a permeance of from 50 GPU to 250 GPU at 120° C.
26. The method of claim 20 , wherein the feed gas comprises a second gas selected from the group consisting of nitrogen, hydrogen, carbon monoxide, and combinations thereof, and
wherein the membrane exhibits a first gas:second gas selectivity of from 20 to 250 at 120° C.
27. The method of claim 20 , wherein the membrane comprises a feed face and a permeate face, and the method further comprises applying a vacuum to the permeate face of the membrane to remove the first gas.
28. The method of claim 20 , wherein the membrane comprises a feed face and a permeate face, and the method further comprises flowing a sweep gas across the permeate face of the membrane to remove the first gas.
29. The method of claim 28 , wherein the sweep gas comprises air.
30. The method of claim 20 , wherein the feed gas has a temperature of at least 100° C.
31. A method of making a membrane comprising depositing a selective polymer layer on a support layer, the selective polymer layer comprising an oxidatively stable carrier dispersed within a hydrophilic polymer matrix,
wherein the oxidatively stable carrier is selected from the group consisting of a quaternary ammonium hydroxide-containing polymer, a quaternary ammonium fluoride-containing polymer, and combinations thereof.