Patents by Inventor De Q. Vu
De Q. Vu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20120048109Abstract: Disclosed herein are mixed matrix membranes which include a continuous phase organic polymer with molecular sieves interspersed therein, the molecular sieves comprising one or more zeolites having an HEU structure type; wherein the membrane exhibits a mixed matrix effect and further wherein the membrane has a N2/CH4 selectivity of greater than about 5, at 35° C. and a pressure of 100 psia (690 kPa). Methods for their preparation and use are also disclosed.Type: ApplicationFiled: August 24, 2010Publication date: March 1, 2012Applicant: CHEVRON U. S. A. INC.Inventors: Daniel Chinn, De Q. Vu, Stephen J. Miller, Paul F. Bryan, Curtis L. Munson
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Publication number: 20110155666Abstract: A method and system using hybrid forward osmosis and nanofiltration is disclosed for treating produced water containing contaminant species. The system comprises a forward osmosis cell and a downstream nanofiltration cell. A draw solution fluid cycles between the forward osmosis cell and the nanofiltration cell. The draw solution contains polyvalent osmotic agents producing polyvalent ions in the draw solution. The passage of monovalent ions through the nanofiltration membrane is hindered due to the presence of conjugate polyvalent ions.Type: ApplicationFiled: December 30, 2009Publication date: June 30, 2011Inventors: Prakhar Prakash, Randall Boyd Pruet, De Q. Vu
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Patent number: 7527775Abstract: A process and method for separating CO2 from a gaseous stream such as natural gas. An ionic liquid comprising an anion having a carboxylate function and an effective amount of water is used as an adsorbent to selectively complex the CO2 yielding a gaseous stream with a greatly reduced CO2 content. The ionic liquid can then be readily be regenerated and recycled.Type: GrantFiled: April 20, 2006Date of Patent: May 5, 2009Assignee: Chevron U.S.A. Inc.Inventors: Daniel Chinn, De Q. Vu, Michael S. Driver, Laura C. Boudreau
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Patent number: 7306647Abstract: A mixed matrix membrane for separating gas components from a mixture of gas components is disclosed. The membrane comprises a continuous phase polymer with inorganic porous particles, preferably molecular sieves, interspersed in the polymer. The polymer has a CO2/CH4 selectivity of at least 20 and the porous particles have a mesoporosity of at least 0.1 cc STP/g. The mixed matrix membrane exhibits an increase in permeability of least 30% with any decrease in selectivity being no more than 10% relative to a membrane made of the neat polymer. The porous particles may include, but are not limited to, molecular sieves such as CVX-7 and SSZ-13, and/or other molecular sieves having the required mesoporosity. A method for making the mixed matrix membrane is also described. Further, a method is disclosed for separating gas components from a mixture of gas components using the mixed matrix membrane with mesoporous particles.Type: GrantFiled: November 19, 2004Date of Patent: December 11, 2007Assignee: Chevron U.S.A. Inc.Inventors: Stephen J. Miller, Alexander Kuperman, De Q. Vu
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Patent number: 7166146Abstract: A mixed matrix membrane is provided which comprises a continuous phase organic polymer and small pore molecular sieves dispersed therein. The molecular sieves have a largest minor crystallographic free diameter of 3.6 Angstroms or less. When these molecular sieves are properly interspersed with a continuous phase polymer, the membrane will exhibit a mixed matrix membrane effect, i.e., a selectivity increase of at least 10% relative to a neat membrane containing no molecular sieves. Finally, methods for making and using such mixed matrix membranes to separate gases from a mixture containing two or more gases are also disclosed.Type: GrantFiled: December 24, 2003Date of Patent: January 23, 2007Assignee: Chevron U.S.A. Inc.Inventors: Stephen J. Miller, Alexander Kuperman, De Q. Vu
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Patent number: 7138006Abstract: A mixed matrix membrane is provided which comprises a continuous phase organic polymer and small pore alumina containing molecular sieves dispersed therein. The molecular sieves have a silica-to-alumina molar ratio of less than 1.0, more preferably, less than 0.3, and most preferably less than 0.1. In some cases, the molecular sieves have no appreciable amounts of silica. Exemplary compositions include aluminophosphates (AlPO) and silicoaluminophosphates (SAPO). When these molecular sieves are properly interspersed with a continuous phase polymer, the membrane will exhibit a mixed matrix membrane effect, i.e., a selectivity increase of at least 10% relative to a neat membrane containing no molecular sieves. The molecular sieves have pores with a largest minor crystallographic free diameter of 4.0 Angstroms or less. Finally, methods for making and using such mixed matrix membranes to separate gases from a mixture containing two or more gases are also disclosed.Type: GrantFiled: December 24, 2003Date of Patent: November 21, 2006Assignee: Chevron U.S.A. Inc.Inventors: Stephen J. Miller, Alexander Kuperman, De Q. Vu
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Patent number: 6755900Abstract: A composition of and a method of making high performance mixed matrix hollow fiber membranes is described. The membranes have a high resistance to plasticization by use of a predetermined amount of crosslinking. The preferred polymer material for the membrane is a polyimide polymer continuous phase comprising ester crosslinks and a molecular sieve material dispersed within the polymer continuous phase. The resultant mixed matrix hollow fiber membrane exhibits a high permeance of CO2 in combination with a high CO2/CH4 selectivity. Another embodiment provides a method of making the mixed matrix hollow fiber membrane from a monesterified polymer followed by final crosslinking after hollow fiber formation.Type: GrantFiled: December 18, 2002Date of Patent: June 29, 2004Assignees: Chevron U.S.A. Inc., University of Texas SystemInventors: William J. Koros, David Wallace, John D. Wind, Stephen J. Miller, Claudia Staudt-Bickel, De Q. Vu
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Publication number: 20030140789Abstract: A composition of and a method of making high performance mixed matrix hollow fiber membranes is described. The membranes have a high resistance to plasticization by use of a predetermined amount of crosslinking. The preferred polymer material for the membrane is a polyimide polymer continuous phase comprising ester crosslinks and a molecular sieve material dispersed within the polymer continuous phase. The resultant mixed matrix hollow fiber membrane exhibits a high permeance of CO2 in combination with a high CO2/CH4 selectivity. Another embodiment provides a method of making the mixed matrix hollow fiber membrane from a monesterified polymer followed by final crosslinking after hollow fiber formation.Type: ApplicationFiled: December 18, 2002Publication date: July 31, 2003Inventors: William J. Koros, David Wallace, John D. Wind, Stephen J. Miller, Claudia Staudt-Bickel, De Q. Vu
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Publication number: 20030131731Abstract: A composition of and a method of making high performance mixed matrix hollow fiber membranes is described. The membranes have a high resistance to plasticization by use of a predetermined amount of crosslinking. The preferred polymer material for the membrane is a polyimide polymer contineous phase comprising ester crosslinks and a molecular sieve material dispersed within the polymer contineous phase. The resultant mixed matrix hollow fiber membrane exhibits a high permeability of CO2 in combination with a high CO2/CH4 selectivity. Another embodiment provides a method of making the mixed matrix hollow fiber membrane from a monesterified polymer followed by final crosslinking after hollow fiber formation.Type: ApplicationFiled: December 20, 2001Publication date: July 17, 2003Inventors: William J. Koros, David Wallace, Stephen J. Miller, Claudia Staudt-Bickel, John Wind, De Q. Vu
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Patent number: 6585802Abstract: Mixed matrix membranes capable of separating carbon dioxide from mixtures including carbon dioxide and methane, and processes for purifying methane using the membranes, are disclosed. The membranes are preferably polymer membranes that include discrete carbon-based molecular sieve particles with sizes of between about 0.5 microns to about 5.0 microns. The particles are formed by pyrolyzing a precursor polymer in the form of a powder or film. The pyrolyzed polymer is then ideally milled to desired small size particles. The preferred ratio of particles to polymer is about 0.25 to about 1.0 by volume. A preferred method for preparing the mixed matrix membrane is by dispersing the particles in a solvent, adding a small quantity of the desired polymer or “sizing agent” to “size” or “prime” the particles, adding a polymer, casting a film of the polymer solution, and evaporating the solvent to form a mixed matrix membrane film.Type: GrantFiled: April 12, 2001Date of Patent: July 1, 2003Assignees: The University of Texas System, Chevron U.S.A. Inc.Inventors: William J. Koros, De Q. Vu, Rajiv Mahajan, Stephen J. Miller
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Patent number: 6562110Abstract: Mixed matrix membranes capable of separating carbon dioxide from mixtures including carbon dioxide and methane, and processes for purifying methane using the membranes, are disclosed. The membranes are preferably polymer membranes, that include discrete carbon-based molecular sieve particles with sizes of between about 0.5 microns to about 5.0 microns. The particles are formed by pyrolyzing a precursor polymer in the form of a powder or film. The pyrolyzed polymer is then ideally milled to desired small size particles. The preferred ratio of particles to polymer is about 0.25 to about 1.0 by volume. A preferred method for preparing the mixed matrix membrane is by dispersing the particles in a solvent, adding a small quantity of the desired polymer or “sizing agent” to “size” or “prime” the particles, adding a polymer, casting a film of the polymer solution, and evaporating the solvent to form a mixed matrix membrane film.Type: GrantFiled: April 12, 2001Date of Patent: May 13, 2003Assignees: Chevron USA Inc., The University of Texas SystemInventors: William J. Koros, De Q. Vu, Rajiv Mahajan, Stephen J. Miller
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Patent number: 6503295Abstract: Mixed matrix membranes capable of separating carbon dioxide from mixtures including carbon dioxide and methane, and processes for purifying methane using the membranes, are disclosed. The membranes are polymer membranes with a selective layer thickness of between about 1000 Angstroms to about 0.005 inch, that include discrete carbon-based molecular sieve particles with sizes of between about 0.5 microns to about 5.0 microns. The preferred ratio of particles to polymer is about 20% to about 50% by volume. A preferred method for preparing the mixed matrix membrane is by dispersing the particles in a solvent, adding a small quantity of the desired polymer or “sizing agent” to “size” or “prime” the particles, adding a polymer, casting a film of the polymer solution, and evaporating the solvent to form a mixed matrix membrane film.Type: GrantFiled: September 20, 2000Date of Patent: January 7, 2003Assignees: Chevron U.S.A. Inc., The University of Texas SystemInventors: William J. Koros, De Q. Vu, Rajiv Mahajan, Stephen J. Miller
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Publication number: 20020056369Abstract: Mixed matrix membranes capable of separating carbon dioxide from mixtures including carbon dioxide and methane, and processes for purifying methane using the membranes, are disclosed. The membranes are preferably polymer membranes with a selective layer thickness of between about 1000 Angstroms to about 0.005 inch, that include discrete carbon-based molecular sieve particles with sizes of between about 0.5 microns to about 5.0 microns. The particles are formed by pyrolyzing a precursor polymer in the form of a powder or film. The pyrolyzed polymer is then ideally milled to desired small size particles. The preferred ratio of particles to polymer is about 0.25 to about 1.0 by volume.Type: ApplicationFiled: April 12, 2001Publication date: May 16, 2002Inventors: William J. Koros, De Q. Vu, Rajiv Mahajan, Stephen J. Miller
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Publication number: 20020053284Abstract: Mixed matrix membranes capable of separating carbon dioxide from mixtures including carbon dioxide and methane, and processes for purifying methane using the membranes, are disclosed. The membranes are preferably polymer membranes with a selective layer thickness of between about 1000 Angstroms to about 0.005 inch, that include discrete carbon-based molecular sieve particles with sizes of between about 0.5 microns to about 5.0 microns. The particles are formed by pyrolyzing a precursor polymer in the form of a powder or film. The pyrolyzed polymer is then ideally milled to desired small size particles. The preferred ratio of particles to polymer is about 0.25 to about 1.0 by volume.Type: ApplicationFiled: April 12, 2001Publication date: May 9, 2002Inventors: William J. Koros, De Q. Vu, Rajiv Mahajan, Stephen J. Miller