Membrane separation of gases

Claim 1

The method of separating a charge gas mixture containing a more permeable gas and a less permeable gas which comprises. passing a charge gas mixture containing a more permeable gas and a less permeable gas into contact with the charge side of a membrane of a high purity alumina containing aluminum-oxygen repeating units and bearing alkoxide groups, said membrane being characterized by a narrow pore size distribution wherein the average Pore Diameter is less than about 40 Å and the Pore Size Distribution is such that at least about 99.5% of the pores have a diameter below 100A; maintaining a pressure on the charge side of said membrane greater than the pressure on the permeate side of said membrane thereby yielding a permeate containing increased quantity of said more permeable gas and decreased quantity of said less permeable gas and a retentate containing decreased quantity of said more permeable gas and an increased quantity of said less permeable gas; recovering from the permeate side of said membrane said permeate containing increased quantity of said more permeable gas and decreased quantity of said less permeable gas; and recovering said retentate containing decreased quantity of said less permeable gas.

Claim 2

The method of separating a charge gas mixture containing a more permeable gas and a less permeable gas which comprises. passing a charge gas mixture containing a more permeable gas and a less permeable gas into contact with the charge side of a membrane of a high purity alumina containing aluminum-oxygen repeating units and bearing alkoxide groups, said membrane being characterized by a narrow pore size distribution wherein the average Pore Diameter is less than about 40 Å and the Pore Size Distribution is such that at least about 99.5% of the pores have a diameter below 100A; maintaining a pressure on the charge side of said membrane greater than the pressure on the permeate side of said membrane thereby yielding a permeate containing increased quantity of said more permeable gas and decreased quantity of said less permeable gas and a retentate containing decreased quantity of said more permeable gas and an increased quantity of said less permeable gas; recovering from the permeate side of said membrane said permeate containing increased quantity of said more permeable gas and decreased quantity of said less permeable gas; and recovering said retentate containing decreased quantity of said less permeable gas.

Claim 7

The method of forming a membrane of an oxide of aluminum which comprises forming a mixture of an aluminum alkoxide, water, and acid peptizing agent, characterized by a mole ratio of water: alkoxide of 0.05-0.9:1; maintaining said mixture at temperature of 40° C.-95° C. for 2-18 hours whereby 2-80 mole % of said alkoxide is hydrolyzed to form a peptized partially hydrolyzed mixture containing high purity alumina containing aluminum-oxygen repeating units and bearing alkoxide groups; contacting the partially hydrolyzed mixture with water vapor at elevated contacting temperature of 100° C.-300° C. and 5-300 psig thereby forming a completely hydrolyzed sol containing high purity alumina; depositing said completely hydrolyzed sol containing high purity alumina containing aluminum-oxygen repeating units and bearing alkoxide groups on a support thereby forming a high purity alumina membrane on said support; and recovering said high purity alumina membrane on said support.

Claim 8

The method of forming a membrane of an oxide of aluminum which comprises forming a mixture of an aluminum alkoxide, water, and acid peptizing agent, characterized by a mole ratio of water: alkoxide of 0.05-0.9:1; maintaining said mixture at temperature of 40° C.-95° C. for 2-18 hours whereby 2-80 mole % of said alkoxide is hydrolyzed to form a peptized partially hydrolyzed mixture containing high purity alumina containing aluminum-oxygen repeating units and bearing alkoxide groups; contacting the partially hydrolyzed mixture with water vapor at elevated contacting temperature of 100° C.-300° C. and 5-300 psig thereby forming a completely hydrolyzed sol containing high purity alumina; depositing said completely hydrolyzed sol containing high purity alumina containing aluminum-oxygen repeating units and bearing alkoxide groups on a support thereby forming a high purity alumina membrane on said support; and recovering said high purity alumina membrane on said support.

Claim 18

The method of forming a membrane of an oxide of aluminum which comprises forming a mixture of aluminum tri-isopropoxide or aluminum tri-sec-butoxide as aluminum tri-alkoxide, water, and nitric acid peptizing agent characterized by a mole ratio of water: alkoxide of 0.2-0.6:1; maintaining said mixture at temperature of 40° C.-95 ° C. for 2-18 hours thereby forming a peptized partially hydrolyzed mixture containing aluminum-oxygen repeating units and bearing alkoxide groups; contacting the partially hydrolyzed mixture with water vapor at 100° C.-300° C. and 5-300 psig thereby forming a completely hydrolyzed sol containing high purity alumina; depositing said completely hydrolyzed sol containing high purity alumina containing aluminum-oxygen repeating units and bearing alkoxidede groups on a support thereby forming a high purity alumina membrane on said support; and recovering said high purity alumina membrane on said support.

Claim 19

The method of forming a membrane of an oxide of aluminum which comprises forming a mixture of aluminum tri-isopropoxide or aluminum tri-sec-butoxide as aluminum tri-alkoxide, water, and nitric acid peptizing agent characterized by a mole ratio of water: alkoxide of 0.2-0.6:1; maintaining said mixture at temperature of 40° C.-95 ° C. for 2-18 hours thereby forming a peptized partially hydrolyzed mixture containing aluminum-oxygen repeating units and bearing alkoxide groups; contacting the partially hydrolyzed mixture with water vapor at 100° C.-300° C. and 5-300 psig thereby forming a completely hydrolyzed sol containing high purity alumina; depositing said completely hydrolyzed sol containing high purity alumina containing aluminum-oxygen repeating units and bearing alkoxidede groups on a support thereby forming a high purity alumina membrane on said support; and recovering said high purity alumina membrane on said support.