초록 ▼

Process and apparatus for the separation and purification of oxygen and nitrogen as well as a novel membrane useful therein are disclosed. The process utilizes novel facilitated transport membranes to selectively transport oxygen from one gaseous stream to another, leaving nitrogen as a byproduct. I

Process and apparatus for the separation and purification of oxygen and nitrogen as well as a novel membrane useful therein are disclosed. The process utilizes novel facilitated transport membranes to selectively transport oxygen from one gaseous stream to another, leaving nitrogen as a byproduct. In the method, an oxygen carrier capable of reversibly binding molecular oxygen is dissolved in a polar organic membrane which separates a gaseous feed stream such as atmospheric air and a gaseous product stream. The feed stream is maintained at a sufficiently high oxygen pressure to keep the oxygen carrier in its oxygenated form at the interface of the feed stream with the membrane, while the product stream is maintained at a sufficiently low oxygen pressure to keep the carrier in its deoxygenated form at the interface of the product stream with the membrane. In an alternate mode of operation, the feed stream is maintained at a sufficiently low temperature and high oxygen pressure to keep the oxygen carrier in its oxygenated form at the interface of the feed stream with the membrane and the product stream is maintained at a sufficiently high temperature to keep the carrier in its deoxygenated form at the interface of the product stream with the membrane. Under such conditions, the carrier acts as a shuttle, picking up oxygen at the feed side of the membrane, diffusing across the membrane as the oxygenated complex, releasing oxygen to the product stream, and then diffusing back to the feed side to repeat the process. Exceptionally and unexpectedly high O 2 /N 2 selectivity, on the order of 10 to 30, is obtained, as well as exceptionally high oxygen permeability, on the order of 6 to 15×10 -8 cm 3 -cm/cm 2 -sec-cmHg, as well as a long membrane life of in excess of 3 months, making the process commercially feasible.

대표청구항 ▼

1. A process for the separation and purification of oxygen and nitrogen comprising: (a) bringing atmospheric air into contact with a membrane, said membrane separating said atmospheric air into a feed stream on one side of said membrane and a product stream on the other side of said membrane, (b

1. A process for the separation and purification of oxygen and nitrogen comprising: (a) bringing atmospheric air into contact with a membrane, said membrane separating said atmospheric air into a feed stream on one side of said membrane and a product stream on the other side of said membrane, (b) maintaining the oxygen partial pressure on the product-stream side of said membrane at least approximately 10 mmHg lower than the oxygen partial pressure on the feed-stream side of said membrane, (c) collecting oxygen from the product-stream side of said membrane and nitrogen from the feed-stream side of said membrane, (d) said membrane comprising a membrane support which is a nonporous polymeric film or a microporous polymeric film selected from polysulfones, polyamides, regenerated cellulose, polyhalogenated hydrocarbons, polyesters, polyurethanes, polyolefins, polycarbonates, polysachharides, polyorganosilanes, and polyorganosiloxanes, said membrane support containing a solvent or solvent mixture, an axial base, and an oxygen carrier, said solvent or solvent mixture, axial base and oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving the axial base and the oxygen carrier when they are present together, said axial base being capable of providing a coordinating atom to the oxygen carrier, and said oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety; and Y is halide, nitrate, thiocyanate or cyanide. 2. A process for the separation and purification of oxygen comprising: (a) bringing a gaseous oxygen-containing stream into contact with a membrane, said membrane separating said gaseous oxygen-containing stream into a feed stream on one side of said membrane and a product stream on the other side of said membrane, (b) maintaining the oxygen partial pressure on the product-stream side of said membrane at least approximately 10 mmHg lower than the oxygen partial pressure on the feed-stream side of said membrane, (c) collecting oxygen from the product-stream side of said membrane, (d) said membrane comprising a membrane support which is a nonporous polymeric film or a microporous polymeric film selected from polysulfones, polyamides, regenerated cellulose, polyhalogenated hydrocarbons, polyesters, polyurethanes, polyolefins, polycarbonates, polysachharides, polyorganosilanes, and polyorganosiloxanes, said membrane support containing a solvent or solvent mixture, an axial base and an oxygen carrier, said solvent or solvent mixture, axial base and oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving the axial base and the oxygen carrier when they are present together, said axial base being capable of providing a coordinating atom to the oxygen carrier, and said oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety; and Y is halide, nitrate, thiocyanate or cyanide. 3. A process for the separation and purification of oxygen and nitrogen comprising: (a) bringing atmospheric air into contact with a membrane, said membrane separating said atmospheric air into a feed stream on one side of said membrane and a product stream on the other side of said membrane, (b) maintaining the temperature on the product-stream side of said membrane at least approximately 5° C. higher than the temperature on the feed-stream side of said membrane, (c) collecting oxygen from the product-stream side of said membrane and nitrogen from the feed-stream side of said membrane, (d) said membrane comprising a membrane support which is a nonporous polymeric film or a microporous polymeric film selected from polysulfones, polyamides, regenerated cellulose, polyhalogenated hydrocarbons, polyesters, polyurethanes, polyolefins, polycarbonates, polysachharides, polyorganosilanes, and polyorganosiloxanes, said membrane support containing a solvent or solvent mixture, an axial base and an oxygen carrier, said solvent or solvent mixture, axial base and oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving the axial base and the oxygen carrier when they are present together, said axial base being capable of providing a coordinating atom to the oxygen carrier, and said oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety; and Y is halide, nitrate, thiocyanate or cyanide. 4. A process for the separation and purification of oxygen comprising: (a) bringing a gaseous oxygen-containing stream into contact with a membrane, said membrane separating said gaseous oxygen-containing stream into a feed stream on one side of said membrane and a product stream on the other side of said membrane, (b) maintaining the temperature on the product-stream side of said membrane at least approximately 5° C. higher than the temperature on the feed-stream side of said membrane, (c) collecting oxygen from the product-stream side of said membrane, (d) said membrane comprising a membrane support which is a nonporous polymeric film or a microporous polymeric film selected from polysulfones, polyamides, regenerated cellulose, polyhalogenated hydrocarbons, polyesters, polyurethanes, polyolefins, polycarbonates, polysachharides, polyorganosilanes, and polyorganosiloxanes, said membrane support containing a solvent or solvent mixture, an axial base and an oxygen carrier, said solvent or solvent mixture, axial base and oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving the axial base and the oxygen carrier when they are present together, said axial base being capable of providing a coordinating atom to the oxygen carrier, and said oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety; and Y is halide, nitrate, thiocyanate or cyanide. 5. A process for the separation and purification of oxygen and nitrogen comprising: (a) bringing atmospheric air into contact with a membrane, said membrane separating said atmospheric air into a feed stream on one side of said membrane and a product stream on the other side of said membrane, (b) maintaining the oxygen partial pressure on the product-stream side of said membrane at least approximately 10 mmHg lower than the oxygen partial pressure on the feed-stream side of said membrane, (c) collecting oxygen from the product-stream side of said membrane and nitrogen from the feed-stream side of said membrane, (d) said membrane comprising a membrane support which is a nonporous polymeric film or a microporous polymeric film selected from polysulfones, polyamides, regenerated cellulose, polyhalogenated hydrocarbons, polyesters, polyurethanes, polyolefins, polycarbonates, polysachharides, polyorganosilanes, and polyorganosiloxanes, said membrane support containing a solvent or solvent mixture and a pentacoordinate oxygen carrier, said solvent or solvent mixture and pentacoordinate oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving said pentacoordinate oxygen carrier, and said pentacoordinate oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety. 6. A process for the separation and purification of oxygen comprising: (a) bringing a gaseous oxygen-containing stream into contact with a membrane, said membrane separating said gaseous oxygen-containing stream into a feed stream on one side of said membrane and a product stream on the other side of said membrane, (b) maintaining the oxygen partial pressure on the product-stream side of said membrane at least approximately 10 mmHg lower than the oxygen partial pressure on the feed-stream side of said membrane, (c) collecting oxygen from the product-stream side of said membrane, (d) said membrane comprising a membrane support which is a nonporous polymeric film or a microporous polymeric film selected from polysulfones, polyamides, regenerated cellulose, polyhalogenated hydrocarbons, polyesters, polyurethanes, polyolefins, polycarbonates, polysachharides, polyorganosilanes, and polyorganosiloxanes, said membrane support containing a solvent or solvent mixture and a pentacoordinate oxygen carrier, said solvent or solvent mixture and pentacoordinate oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving said pentacoordinate oxygen carrier, and said pentacoordinate oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety. 7. A process for the separation and purification of oxygen and nitrogen comprising: (a) bringing atmospheric air into contact with a membrane, said membrane separating said atmospheric air into a feed stream on one side of said membrane and a product stream on the other side of said membrane, (b) maintaining the temperature on the product-stream side of said membrane at least approximately 5° C. higher than the temperature on the feed-stream side of said membrane, (c) collecting oxygen from the product-stream side of said membrane and nitrogen from the feed-stream side of said membrane, (d) said membrane comprising a membrane support which is a nonporous polymeric film or a microporous polymeric film selected from polysulfones, polyamides, regenerated cellulose, polyhalogenated hydrocarbons, polyesters, polyurethanes, polyolefins, polycarbonates, polysachharides, polyorganosilanes, and polyorganosiloxanes, said membrane support containing a solvent or solvent mixture and a pentacoordinate oxygen carrier, said solvent or solvent mixture and pentacoordinate oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving said pentacoordinate oxygen carrier, and said pentacoordinate oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety. 8. A process for the separation and purification of oxygen comprising: (a) bringing a gaseous oxygen-containing stream into contact with a membrane, said membrane separating said gaseious oxygen-containing stream into a feed stream on one side of said membrane and a product stream on the other side of said membrane, (b) maintaining the temperature on the product-stream side of said membrane at least approximately 5° C. higher than the temperature on the feed-stream side of said membrane, (c) collecting oxygen from the product-stream side of said membrane, (d) said membrane comprising a membrane support which is a nonporous polymeric film or a microporous polymeric film selected from polysulfones, polyamides, regenerated cellulose, polyhalogenated hydrocarbons, polyesters, polyurethanes, polyolefins, polycarbonates, polysachharides, polyorganosilanes, and polyorganosiloxanes, said membrane support containing a solvent or solvent mixture and a pentacoordinate oxygen carrier, said solvent or solvent mixture and pentacoordinate oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving said pentacoordinate oxygen carrier, and said pentacoordinate oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety. 9. The process of claims 1, 2, 5 or 6 wherein the oxygen partial pressure on the feed-stream side of said membrane is substantially atmospheric or less than atmospheric. 10. The process of claim 1, 2, 5 or 6 wherein the oxygen partial pressure on the feed-stream side of said membrane is at least about 10 mmHg higher than atmospheric. 11. The process of claim 1, 2, 5 or 6 conducted at a temperature of between about -50° C. and +100° C. 12. The process of claim 3, 4, 7 or 8 wherein the temperature on the feed-stream side of said membrane is between about -50° C. and +95° C. 13. The process of claim 1, 2, 3, 4, 5, 6, 7 or 8 wherein the metal is cobalt. 14. The process of claim 1, 2, 3 or 4 wherein the solvent or solvent mixture is selected from lactones, sulfoxides, nitriles, amines, amides, esters, ethers, and other nitrogen-containing liquids, the axial base is selected from secondary or tertiary nitrogen-atom-containing Lewis bases, imidazoles, ketones, amides, amines, sulfoxides, pyridines and pyrazines, and the oxyen carrier is selected from metal-containing bis(acetylacetone)ethylenediimines, N,N'bis(salicylidene)ethylenediimines, bis(2-amino-1-benzaldehyde)ethylenediimines, dry-cave compounds, and N,N'-substituted-ethylenediamines. 15. The process of claim 1, 2, 3 or 4 wherein the solvent or solvent mixture is selected from at least one of gamma-butyrolactone, dimethylsulfoxide, propylene carbonate, diethylsulfoxide, N-methylpyrrolidone, dimethylacetamide, gamma-valerolactone, delta-valerolactone, epsilon-caprolactone, tributylphosphate, dimethylformamide, diglyme and benzonitrile, and the axial base is selected from at least one of 1-methylimidazole, 2-methylimidazole, 1,2-dimethylimidazole, dimethylsulfoxide, N,N'-diethylethylenediamine, 4-dimethylaminopyridine, 4-aminopyridine, 4,4-bipyridine, 4-methoxypyridine, 4-methylaminopyridine, 3,4-lutidine, 3,5-lutidine, pyridine, 4-methylpyridine, 4-cyanopyridine, pyrazine, 4-pyrrolidinopyridine and N-methylpyrazinium halides. 16. The process of claim 1, 2, 3 or 4 wherein the oxygen carrier is N,N'-bis(salicylideneimino)di-n-propylaminecobalt(II). 17. The process of claim 1, 2, 3 or 4 wherein the oxygen carrier is N,N'-bis(3-methoxysalicylidene)ethylenediaminecobalt(II). 18. The process of claim 1, 2, 3 or 4 wherein the oxygen carrier is N,N'-bis(3-methoxysalicylidene)tetramethylethylenediaminecobalt(II). 19. The process of claim 1, 2, 3 or 4 wherein the oxygen carrier is ##STR## wherein R 1 is a branched or straight-chain hydrocarbon or hetero-atom-containing bridge; R 2 is hydrogen or methyl; R 3 is methyl or benzyl; and R 4 is alkyl containing 2 to 3 carbon atoms. 20. A membrane useful for the separation of oxygen and nitrogen from atmospheric air comprising a membrane support which is a nonporous polymeric film or a microporous polymeric film selected from polysulfones, polyamides, regenerated cellulose, polyhalogenated hydrocarbons, polyesters, polyurethanes, polyolefins, polycarbonates, polysachharides, polyorganosilanes, and polyorganosiloxanes, said membrane support, a solvent or solvent mixture, an axial base and an oxygen carrier, said solvent or solvent mixture, axial base and oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving the axial base and the oxygen carrier when they are present together, said axial base being capable of providing a coordinating atom to the oxygen carrier, and said oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety; and Y is halide, nitrate, thiocyanate or cyanide. 21. The membrane of claim 20 wherein the membrane support is a microporous polymeric film selected from polysulfones, polyamides, cellulose derivatives, polyhalogenated hydrocarbons polyesters, polyurethanes, polyolefins polycarbonates, polysaccharides, polyorganosilanes, and polyorganosiloxanes, the solvent or solvent mixture is selected from lactones, lactams, sulfoxides, nitriles, amines, amides, esters, ethers and other nitrogen-containing liquids, and the axial base is selected from Lewis bases containing secondary or tertiary nitrogen atoms, imidazoles, ketones, amides, amines, sulfoxides, pyrazines and pyridines. 22. The membrane of claim 20 wherein the solvent is selected from at least one of gamma-butyrolactone, dimethylsulfoxide, propylene carbonate, diethylsulfoxide, N-methylpyrrolidone, dimethylacetamide, gamma-valerolactone, delta-valerolactone, dimethylformamide, formamide, epsilon-caprolactone, tributylphosphate, diglyme and benzonitrile, the axial base is selected from at least one of 1-methylimidazole, 2-methylimidazole, 1,2,-dimethylimidazole, dimethylsulfoxide, N,N'-diethylethylenediamine, 4-dimethylaminopyridine, 4-aminopyridine, 4,4-bipyridine, 4-methoxypyridine, 4-methylaminopyridine, 3,4-lutidine, 3,5-lutidine, pyridine, 4-methylpyridine, 4-cyanopyridine, pyrazine, 4-pyrrolidinopyridine and N-methylpyrazinium halides, and the oxygen carrier is selected from N,N'-bis(3-methoxysalicylidene)ethylenediaminecobalt(II), N,N'-bis(3-methoxysalicylidene)tetramethylethylenediaminecobalt(II), and ##STR## wherein R 1 is a branched or straight-chain hydrocarbon or hetero-atom-containing bridge; R 2 is hydrogen or methyl; R 3 is methyl or benzyl; and R 4 is alkyl containing 2 to 3 carbon atoms. 23. The membrane of claim 20 wherein the solvent is selected from gamma-butyrolactone and N-methylpyrrolidone and mixtures thereof, the axial base is 4-dimethylaminopyridine and the oxygen carrier is N,N'-bis(3-methoxysalicylidene)tetramethylethylenediaminecobalt(II). 24. The membrane of claim 20 wherein the oxygen carrier is N,N'-bis(3-methoxysalicylidene)tetramethylethylenediaminecobalt(II). 25. The membrane of claim 20 wherein the solvent is selected from gamma-butyrolactone and N-methylpyrrolidone and mixtures thereof, the axial base is selected from 4-aminopyridine and 4-cyanopyridine and the oxygen carrier is N,N'-bis(3-methoxysalicylidene)tetramethylethylenediaminecobalt(II). 26. The membrane of claim 20 wherein the solvent or solvent mixture contains an additive selected from the group consisting of less than or equal to 20% by weight water or an organic or inorganic acid or base. 27. A membrane useful for the separation of oxygen and nitrogen from atmospheric air comprising a membrane support, a solvent or solvent mixture and a pentacoordinate oxygen carrier, said solvent or solvent mixture and pentacoordinate oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving said pentacoordinate oxygen carrier, and said pentacoordinate oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety. 28. The membrane of claim 27 wherein the oxygen carrier is N,N'-bis(salicylideneimino)di-n-propylaminecobalt(II). 29. Apparatus for the separation and purification of oxygen and nitrogen comprising: (a) membrane means, (b) means for bringing atmospheric air into contact with said membrane means, said membrane means separating said atmospheric air into a feed stream on one side of said membrane means and a product stream on the other side of said membrane means, (c) means for maintaining the oxygen partial pressure on the product-stream side of said membrane means at least approximately 10 mmHg lower than the oxygen partial pressure on the feed-stream side of said membrane means, (d) means for collecting oxygen from the product-stream side of said membrane means and nitrogen from the feed-stream side of said membrane means; (e) said membrane comprising a membrane support which is a nonporous polymeric film or a microporous polymeric film selected from polysulfones, polyamides, regenerated cellulose, polyhalogenated hydrocarbons, polyesters, polyurethanes, polyolefins, polycarbonates, polysachharides, polyorganosilanes, and polyorganosiloxanes, said membrane support containing a solvent or solvent mixture, an axial base and an oxygen carrier, said solvent or solvent mixture, axial base and oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving the axial base and the oxygen carrier when they are present together, said axial base being capable of providing a coordinating atom to the oxygen carrier, and said oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety; and Y is halide, nitrate, thiocyanate or cyanide. 30. Apparatus for the separation and purification of oxygen comprising: (a) membrane means, (b) means for bringing a gaseous oxygen-containing stream into contact with said membrane means, said membrane means separating said gaseous oxygen-containing stream into a feed stream on one side of said membrane means and a product stream on the other side of said membrane means, (c) means for maintaining the oxygen partial pressure on the product-stream side of said membrane means at least approximately 10 mmHg lower than the oxygen partial pressure on the feed-stream side of said membrane means, (d) means for collecting oxygen from the product-stream side of said membrane means, (e) said membrane comprising a membrane support which is a nonporous polymeric film or a microporous polymeric film selected from polysulfones, polyamides, regenerated cellulose, polyhalogenated hydrocarbons, polyesters, polyurethanes, polyolefins, polycarbonates, polysachharides, polyorganosilanes, and polyorganosiloxanes, said membrane support containing a solvent, an axial base, an oxygen carrier, said solvent or solvent mixture, axial base and oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving the axial base and the oxygen carrier when they are present together, said axial base being capable of providing a coordinating atom to the oxygen carrier, and said oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety; and Y is halide, nitrate, thiocyanate or cyanide. 31. Apparatus for the separation and purification of oxygen and nitrogen comprising: (a) membrane means, (b) means for bringing atmospheric air into contact with said membrane means, said membrane means separating said atmospheric air into a feed stream on one side of said membrane means and a product stream on the other side of said membrane means, (c) temperature maintenance means for maintaining the temperature on the product-stream side of said membrane means at least approximately 5° C. higher than the temperature on the feed-stream side of said membrane means, (d) means for collecting oxygen from the product-stream side of said membrane means and nitrogen from the feed-stream side of said membrane means, (e) said membrane comprising a membrane support which is a nonporous polymeric film or a microporous polymeric film selected from polysulfones, polyamides, regenerated cellulose, polyhalogenated hydrocarbons, polyesters, polyurethanes, polyolefins, polycarbonates, polysachharides, polyorganosilanes, and polyorganosiloxanes, said membrane support containing a solvent or solvent mixture, an axial base and an oxygen carrier, said solvent or solvent mixture, axial base and oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving the axial base and the oxygen carrier when they are present together, said axial base being capable of providing a coordinating atom to the oxygen carrier, and said oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety; and Y is halide, nitrate, thiocyanate or cyanide. 32. Apparatus for the separation and purification of oxygen comprising: (a) membrane means, (b) means for bringing a gaseous oxygen-containing stream into contact with said membrane means, said membrane means separating said gaseous oxygen-containing stream into a feed stream on one side of said membrane means and a product stream on the other side of said membrane means, (c) temperature maintenance means for maintaining the temperature on the product-stream side of said membrane means at least approximately 5° C. higher than the temperature on the feed-stream side of said membrane means, (d) means for collecting oxygen from the product-stream side of said membrane means, (e) said membrane comprising a membrane support which is a nonporous polymeric film or a microporous polymeric film selected from polysulfones, polyamides, regenerated cellulose, polyhalogenated hydrocarbons, polyesters, polyurethanes, polyolefins, polycarbonates, polysachharides, polyorganosilanes, and polyorganosiloxanes, said membrane support containing a solvent or solvent mixture, an axial base and an oxygen carrier, said solvent or solvent mixture, axial base and oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving the axial base and the oxygen carrier when they are present together, said axial base being capable of providing a coordinating atom to the oxygen carrier, and said oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety; and Y is halide, nitrate, thiocyanate or cyanide. 33. The apparatus of claim 29, 30, 31 or 32 wherein the metal is cobalt. 34. The apparatus of claim 29, 30, 31 or 32 wherein the solvent or solvent mixture is selected from at least one of gamma-butyrolactone, dimethylsulfoxide, propylene carbonate, diethylsulfoxide, N-methylpyrrolidone, dimethylacetamide, gamma-valerolactone, delta-valerolactone, epsilon-caprolactone, tributylphosphate, dimethylformamide, diglyme and benzonitrile, the axial base is selected from at least one of 1-methylimidazole, 2-methylimidazole, 1,2,-dimethylimidazole, dimethylsulfoxide, N,N'-diethylethylenediamine, 4-dimethylaminopyridine, 4-aminopyridine, 4,4-bipyridine, 4-methoxypyridine, 4-methylaminopyridine, 3,4-lutidine, 3,5-lutidine, pyridine, 4-methylpyridine, 4-cyanopyridine, pyrazine, 4-pyrrolidinopyridine and N-methylpyrazinium halides, and the oxygen carrier is selected from N,N'-bis(3-methoxysalicylidene)ethylenediaminecobalt(II), N,N'-bis(3-methoxysalicylidene)tetramethylethylenediaminecobalt(II), and ##STR## wherein R 1 is a branched or straight-chain hydrocarbon or hetero-atom-containing bridge; R 2 is hydrogen or methyl; R 3 is methyl or benzyl; and R 4 is alkyl containing 2 to 3 carbon atoms. 35. Apparatus for the separation and purification of oxygen and nitrogen comprising: (a) membrane means, (b) means for bringing atmospheric air into contact with said membrane means, said membrane means separating said atmospheric air into a feed stream on one side of said membrane means and a product stream on the other side of said membrane means, (c) means for maintaining the oxygen partial pressure on the product-stream side of said membrane means at least approximately 10 mmHg lower than the oxygen partial pressure on the feed-stream side of said membrane means, (d) means for collecting oxygen from the product-stream side of said membrane means and nitrogen from the feed-stream side of said membrane means, (e) said membrane comprising a membrane support which is a nonporous polymeric film or a microporous polymeric film selected from polysulfones, polyamides, regenerated cellulose, polyhalogenated hydrocarbons, polyesters, polyurethanes, polyolefins, polycarbonates, polysachharides, polyorganosilanes, and polyorganosiloxanes, said membrane support containing a solvent or solvent mixture and a pentacoordinate oxygen carrier, said solvent or solvent mixture and pentacoordinate oxygen carrier being in the liquid phase when present together, said solvent or solvent mixture being capable of dissolving said pentacoordinate oxygen carrier, and said pentacoordinate oxygen carrier being a metal-containing complex having any of the structures ##STR## wherein M is cobalt, iron, copper, nickel, manganese, ruthenium or rhodium; X is --O--, --S--, ##STR## R is hydrogen, alkyl, aryl, halogen, alkoxy or a nitrogen-containing moiety. 36. The apparatus of claim 34 wherein the oxygen carrier is N,N'-bis(salicylideneimino)di-n-propylaminecobalt(II).