Process of separating complexable materials employing semipermeable polymer film

Claim 2

IN A METHOD FOR SEPARATING A MATERIAL FROM A MIXTURE WHICH COMPRISES CONTACTING SAID MIXTURE CONTAINING SAID MATERIAL WITH A FIRST SIDE OF AN ESENTIALLY SOLID, WATER-INSOLUBLE HYDROPHILIC, SEMI-PERMEABLE MEMBRANE HAVING THEREIN AN AQUEOUS LIQUID BARRIER HAVING METAL IONS WHICH COMBINE WITH SAID MATERIAL TO FORM A WATER-SOLUBLE COMPLEX, THE PARTIAL PRESSURE OF SAID MATERIAL ON A SECOND SIDE OF SAID SEMIPERMEABLE MEMBRANE BEING SUFFICIENTLY LESS THAN THE PARTIAL PRESSURE OF SAID MATERIAL IN SAID MIXTURE TO PROVIDE SEPARATED MATERIAL ON SAID SECOND SIDE OF SAID SEMI-PERMEABLE MEMBRANE, SAID SEPARATED MATERIAL HAVING A TRANSFER RATE ACROSS SAID LIQUID BARRIER THAT IS GREATER THAN AT LEAST ONE OTHER COMPONENT OF SAID MIXTURE, AND REMOVING SAID SEPARATED MATERIAL FROM THE VICINITY OF SAID SECOND SIDE OF SAID SEMI-PERMEABLE MEMBRANE, THE IMPROVEMENT WHICH COMPRISES EMPLOYING AS SAID SEMI-PERMECABLE MEMBRANE A SEMI-PERMEABLE POLYMER FILM HAVING THEREIN AN AQUEOUS LIQUID BARRIER HAVING IN SOLUTION SAID COMPLEX-FORMING METAL IONS WHICH COMBINE WITH SAID MATERIAL TO FORM A WATER-SOLUBLE COMPLEX, SAID POLYMER FILM HAVING AN INCREASED PERMEABILITY TO SAID MATERIAL RESULTING FROM FORMING THE SEMI-PERMEABLE POLYMER FILM FROM A SOLUTION HAVING DISSOLVED THEREIN FILM-FORMING MATERIAL AND AN AMOUNT OF PORE-FORMING MATERIAL SUFFICIENT TO INCREASE THE PERMEABILITY OF THE FILM WHEN REMOVED FROM THE FILM AND REMOVING THE PORE-FORMING MATERIAL FROM THE FILM.

Claim 3

In a method for separating aliphatically-unsaturated hydrocarbon of 2 to 4 carbon atoms which comprises contacting a vaporous mixture containing said aliphatically-unsaturated hydrocarbon with a first side of an essentially solid, water-insoluble, hydrophilic semi-permeable mambrane having therein an aqueous liquid barrier, said semi-permeable membrane being permeable to said vaporous mixture in the absence of said aqueous liquid, said liquid barrier having metal ions which combine with said unsaturated hydrocarbon to form a water-soluble complex, the partial pressure of said unsaturated hydrocarbon on a second side of said semi-permeable membrane being sufficiently less than the partial pressure of said unsaturated hydrocarbon in said vaporous mixture to provide separated unsaturated hydrocarbon on said second side of said semi-permeable membrane, and removing separated unsaturated hydrocarbon from the vicinity of said second side of said semi-permeable membrane, the improvement which comprises employing as said semi-permeable membrane a semi-permeable polymer film having therein an aqueous liquid barrier having in solution said complex-forming metal ions which combine with said aliphatically-unsaturated hydrocarbon, said polymer film having an increased permeability to said aliphatically-unsaturated hydrocarbon resulting from forming the semi-permeable polymer film from a solution having dissolved therein film-forming material and an amount of solvent-soluble, pore-froming material sufficient to increase the permeability of the film when removed from the film and contacting the film with a solvent which dissolves and removes the pore-forming material from the film without dissolving the film formed from the film-forming material.

Claim 4

In a method for separating aliphatically-unsaturated hydrocarbon of 2 to 4 carbon atoms which comprises contacting a vaporous mixture containing said aliphatically-unsaturated hydrocarbon with a first side of an essentially solid, water-insoluble, hydrophilic semi-permeable mambrane having therein an aqueous liquid barrier, said semi-permeable membrane being permeable to said vaporous mixture in the absence of said aqueous liquid, said liquid barrier having metal ions which combine with said unsaturated hydrocarbon to form a water-soluble complex, the partial pressure of said unsaturated hydrocarbon on a second side of said semi-permeable membrane being sufficiently less than the partial pressure of said unsaturated hydrocarbon in said vaporous mixture to provide separated unsaturated hydrocarbon on said second side of said semi-permeable membrane, and removing separated unsaturated hydrocarbon from the vicinity of said second side of said semi-permeable membrane, the improvement which comprises employing as said semi-permeable membrane a semi-permeable polymer film having therein an aqueous liquid barrier having in solution said complex-forming metal ions which combine with said aliphatically-unsaturated hydrocarbon, said polymer film having an increased permeability to said aliphatically-unsaturated hydrocarbon resulting from forming the semi-permeable polymer film from a solution having dissolved therein film-forming material and an amount of solvent-soluble, pore-froming material sufficient to increase the permeability of the film when removed from the film and contacting the film with a solvent which dissolves and removes the pore-forming material from the film without dissolving the film formed from the film-forming material.

Claim 5

The method of claim 2 in which said unsaturated hydrocarbon separated is ethylene.

Claim 6

The method of claim 3 in which said vaporous mixture contains ethylene and one or both of methane and ethane.

Claim 7

The method of claim 2 wherein the pore-forming material is citric acid and the solvent for the pore-forming material containing water.

Claim 8

The method of claim 5 wherein the unsaturated hydrocarbon separated is ethylene.

Claim 9

The method of claim 2 wherein the amount of pore-forming material is a minor amount based on the total amount of film-forming material and pore-forming material in said solution.

Claim 10

The method of claim 7 wherein the pore-forming material is citric acid and the solvent for the pore-forming material contains water.

Claim 11

The method of claim 1 in which said metal ions are noble metal ions.

Claim 12

The method of claim 9 in which saId noble metal ions are silver.

Claim 13

The method of claim 10 in which the unsaturated hydrocarbon separated is ethylene.

Claim 14

The method of claim 11 in which said mixture contains ethylene and one or both of methane and ethane.

Claim 15

The method of claim 12 wherein the amount of pore-forming material is a minor amount based on the total amount of film-forming material and pore-forming material in said solution.

Claim 16

The method of claim 13 wherein the pore-forming material is citric acid and the solvent for the pore-forming material contains water.

Claim 17

The method of claim 14 wherein the semi-permeable membrane is nylon.

Claim 18

The method of claim 2 wherein the semi-permeable membrane is nylon.