Systems, compositions, and methods for fluid purification
Disclosed herein are membranes comprising a substrate, a support layer, and a selective layer. In some embodiments the membrane may further comprise a permeable layer. Methods of forming membranes are also disclosed comprising forming a support layer on a substrate, removing adsorbed species from the support layer, preparing a solution containing inorganic materials of a selective layer, contacting the support layer with the solution, drying the membrane, and exposing the membrane to rapid thermal processing. Also disclosed are methods of fluid purification comprising providing a membrane having a feed side and a permeable side, passing a fluid mixture across the feed side of the membrane, providing a driving force for transmembrane permeation, removing from the permeate side a permeate stream enriched in a purified fluid, and withdrawing from the feed side a fluid that is depleted in a purified fluid.
1. A membrane comprising:
a substrate;
a support layer on the substrate, the support layer comprising a plurality of pores;
a selective layer on the support layer, the selective layer having a plurality of substantially unconnected pores in fluid communication with the pores of the support layer; and
a permeable layer on the selective layer,
wherein the support layer comprises a first polymer and the permeable layer comprises a second polymer, and
wherein the membrane has a CO 2 :N 2 selectivity of at least 7.5 at 55° C. and 1.24 atm feed pressure.
2. The membrane of claim 1 , wherein the substrate is fibrous.
3. The membrane of claim 1 , wherein the substrate comprises a non-woven fabric.
4. The membrane of claim 3 , wherein the non-woven fabric comprises a polyester.
5. The membrane of claim 1 , wherein the first polymer comprises a polymer selected from the group consisting of cross-linked polymers and copolymers, phase separated polymers and copolymers, porous condensed polymers, polyamides, polyimides, polypyrrolones, polyesters, sulfone-based polymers, polymeric organosilicones, fluorinated polymers, and polyolefinic species.
6. The membrane of claim 5 , wherein the first polymer comprises a sulfone-based polymer.
7. The membrane of claim 1 , wherein the selective layer comprises an inorganic material.
8. The membrane of claim 7 , wherein the inorganic material comprises an inorganic material selected from the group consisting of alumina, silica, titania, zirconia, metal oxides, transition-metal oxides, palladium, platinum, nickel, transition-metal catalysts, transition-metals adsorbed on nonreactive supports, zeolites, clays, metal alloys, composites of metal, composites of nonmetals, and mixtures thereof.
9. The membrane of claim 8 , wherein the inorganic material comprises zeolite Y.
10. The membrane of claim 1 , wherein the second polymer comprises a polymer operable to increase the selectivity of fluid separation by the membrane.
11. The membrane of claim 10 , wherein the second polymer comprises a polymer selected from the group consisting of cross-linked polymers and copolymers, phase separated polymers and copolymers, porous condensed polymers, polyamides, polyimides, polypyrrolones, polyesters, sulfone-based polymers, polymeric organosilicones, fluorinated polymers, and polyolefinic species.
12. The membrane of claim 11 , wherein the polymeric organosilicone comprises a polymeric organosilicone selected from the group consisting of polydimethylsiloxane, polydiethylsiloxane, polydi-iso-propylsiloxane, polydiphenylsiloxane, and either partially fluorinated or perfluorinated derivatives thereof.
13. The membrane of claim 1 , wherein the membrane is selectively permeable for a fluid selected from the group consisting of hydrogen, helium, nitrogen, argon, carbon dioxide, carbon monoxide, oxygen, air, methane, hydrogen sulfide, sulfur dioxide, sulfur trioxide, nitrogen oxides, ammonia, fluorine, chlorine, bromine, hydrogen chloride, water, alcohols, gaseous hydrocarbons, non-gaseous hydrocarbons, gaseous olefins, non-gaseous olefins, and acetylene.
14. The membrane of claim 1 , wherein the membrane is selectively permeable to a fluid selected from the group consisting of carbon dioxide, hydrogen sulfide, sulfur dioxide, sulfur trioxide, nitrogen oxide, hydrogen chloride, water, and combinations thereof.
15. The membrane of claim 1 , wherein the membrane has a CO 2 :N 2 selectivity of about 400 at 58° C. and 1 atm feed pressure.
16. The membrane of claim 1 , wherein the membrane has a CO 2 permeance of from 35 to 6000 GPU.
17. The membrane of claim 1 , wherein the membrane has a CO 2 :N 2 selectivity of at least 20 at 55° C. and 1.24 atm feed pressure.