Separation by membrane techniques
AssigneeTexaco Inc.
InventorsMitri S. Najjar, Martin D. Hilmar
Life of this patent
Estimating the term…
Abstract
Mixture of gases such as hydrogen/carbon dioxide may be separated by use of membrane formed by reaction of an aluminum alkoxide with steam at high temperatures and pressures.
Claims15
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 a membrane of a high purity alumina containing aluminum-oxygen repeating units and bearing alkoxide groups;
- 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 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 more permeable gas and an increased quantity of said less permeable gas.
A 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 a membrane of a high purity alumina containing aluminum-oxygen repeating units;
- 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 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 more permeable gas and an increased quantity of said less permeable gas.
A membrane comprising a high purity alumina containing aluminum-oxygen repeating units and bearing alkoxide groups and characterized by a narrow pore size distribution wherein >70% of the pores have a radius less than about 12 A and the BET surface area is 150-400 m.sup.2 /g.
A membrane comprising a high purity alumina aluminum-oxygen repeating units and bearing alkoxide groups and being characterized by a narrow pore size distribution wherein >70% of the pores have a radius less than about 12A and the BET surface area is 150-400 m.sup.2 /g, prepared by the process which comprises
- contacting an aluminum alkoxide with steam in the presence of an acid peptizing agent at elevated decomposition temperature and pressure thereby decomposing said alkoxide and forming a peptized hydrolyzed mixture containing high purity alumina containing aluminum-oxygen repeating units;
- depositing said peptized hydrolyzed mixture containing high purity alumina containing aluminum-oxygen repeating units and bearing alkoxide groups on a support thereby forming a high purity alumina membrane on a support;
- and
- recovering said high purity membrane on said support.
The method of forming a membrane of an oxide of aluminum which comprises
- contacting an aluminum alkoxide with steam in the presence of an acid peptizing agent at elevated decomposition temperature and pressure thereby decomposing said alkoxide and forming a peptized hydrolyzed mixture containing high purity alumina containing aluminum-oxygen repeating units;
- depositing said peptized hydrolyzed mixture containing high purity alumina containing aluminum-oxygen repeating units and bearing alkoxide groups on a support thereby forming a high purity alumina membrane on a support;
- and
- recovering said high purity membrane on said support.
The method of forming a membrane of aluminum oxide comprises
- contacting aluminum tri-isopropoxide or aluminum sec-butoxide with steam in the presence of nitric acid peptizing agent at elevated decomposition temperature of 100.degree. C.-275.degree. C. and pressure of 1-150 psig thereby decomposing aluminum tri-isopropoxide or aluminum tri-sec-butoxide and forming a peptized hydrolyzed mixture containing high purity alumina containing aluminum-oxygen repeating units and bearing isopropoxide or sec-butoxide groups;
- depositing said peptized hydrolyzed mixture containing high purity alumina containing aluminum-oxygen repeating units and bearing isopropoxide or sec-butoxide terminal groups on a support thereby forming a high purity membrane on a support;
- and
- recovering said high purity membrane on said support.
Dependencies are inferred from the claim text.