Patents by Inventor Mark K. Brayden
Mark K. Brayden 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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Patent number: 11772053Abstract: A carbon molecular sieve (CMS) membrane having improved separation characteristics for separating olefins from their corresponding paraffins is comprised of carbon with at most trace amounts of sulfur and a group 13 metal. The CMS membrane may be made by pyrolyzing a precursor polymer devoid of sulfur in which the precursor polymer has had a group 13 metal incorporated into it, wherein the metal is in a reduced state. The pyrolyzing for the precursor having the group 13 metal incorporated into it is performed in a nonoxidizing atmosphere and at a heating rate and temperature such that the metal in a reduced state (e.g., covalently bonded to carbon or nitrogen or in the metal state).Type: GrantFiled: October 27, 2022Date of Patent: October 3, 2023Assignees: Dow Global Technologies LLC, Georgia Tech Research CorporationInventors: Yu-Han Chu, William J. Koros, Liren Xu, Mark K. Brayden, Marcos V. Martinez
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Patent number: 11666865Abstract: The invention is an improved method of making an improved carbon molecular sieve (CMS) membrane in which a precursor polymer (e.g., polyimide) is pyrolyzed at a pyrolysis temperature to form a CMS membrane that is cooled to ambient temperature (about 40° C. or 30° C. to about 20° C.). The CMS membrane is then reheated to a reheating temperature of at least 250° C. to 400° C. to form the improved CMS membrane. The CMS have a novel microstructure as determined by Raman spectroscopy. The improved CMS membranes have shown an improved combination of selectivity and permeance as well as stability for separating light hydrocarbon gas molecules such as C1 to C6 hydrocarbon gases (e.g., methane, ethane, propane, ethylene, propylene, butane, butylene).Type: GrantFiled: April 3, 2019Date of Patent: June 6, 2023Assignees: Dow Global Technologies LLC, Georgia Tech Research CorporationInventors: Liren Xu, Thomas Fitzgibbons, Mark K. Brayden, Marcos V. Martinez, William J. Koros, Wulin Qiu
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Publication number: 20230088542Abstract: A carbon molecular sieve (CMS) membrane having improved separation characteristics for separating olefins from their corresponding paraffins is comprised of carbon with at most trace amounts of sulfur and a group 13 metal. The CMS membrane may be made by pyrolyzing a precursor polymer devoid of sulfur in which the precursor polymer has had a group 13 metal incorporated into it, wherein the metal is in a reduced state. The pyrolyzing for the precursor having the group 13 metal incorporated into it is performed in a nonoxidizing atmosphere and at a heating rate and temperature such that the metal in a reduced state (e.g., covalently bonded to carbon or nitrogen or in the metal state).Type: ApplicationFiled: October 27, 2022Publication date: March 23, 2023Applicants: Dow Global Technologies LLC, Georgia Tech Research CorporationInventors: Yu-Han Chu, William J. Koros, Liren Xu, Mark K. Brayden, Marcos V. Martinez
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Patent number: 11517857Abstract: A method of making a hollow fiber carbon molecular sieve is comprised of heating a hollow polymer fiber to a carbonization temperature in an atmosphere that is non-oxidizing to form a hollow fiber carbon molecular sieve, wherein during at least a portion of the heating a tensile force is applied to the hollow polymer fiber. The method may improve the separation of gases similar in size such a propylene from propane.Type: GrantFiled: March 20, 2018Date of Patent: December 6, 2022Assignee: Dow Global Technologies LLCInventors: Liren Xu, Rahul Sharma, Thomas Fitzgibbons, Mark K. Brayden, Marcos V. Martinez
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Patent number: 11504675Abstract: A carbon molecular sieve (CMS) membrane having improved separation characteristics for separating olefins from their corresponding paraffins is comprised of carbon with at most trace amounts of sulfur and a group 13 metal. The CMS membrane may be made by pyrolyzing a precursor polymer devoid of sulfur in which the precursor polymer has had a group 13 metal incorporated into it, wherein the metal is in a reduced state. The pyrolyzing for the precursor having the group 13 metal incorporated into it is performed in a nonoxidizing atmosphere and at a heating rate and temperature such that the metal in a reduced state (e.g., covalently bonded to carbon or nitrogen or in the metal state).Type: GrantFiled: June 8, 2018Date of Patent: November 22, 2022Assignees: Dow Global Technologies LLC, Georgia Tech Research CorporationInventors: Yu-Han Chu, William J. Koros, Liren Xu, Mark K. Brayden, Marcos V. Martinez
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Patent number: 11471824Abstract: A carbon molecular sieve (CMS) membrane having improved separation characteristics for separating olefins from their corresponding paraffins is comprised of carbon with at most trace amounts of sulfur and a transition metal, wherein the transition metal is one or more of a group 4-10 and 12 transition metal. The CMS membrane may be made by pyrolyzing a precursor polymer devoid of sulfur in which the precursor polymer has had a transition metal incorporated into it. The pyrolyzing for the precursor having the transition metal incorporated into it is performed in a nonoxidizing atmosphere and at a heating rate and temperature such that the metal has a valence greater than zero (i.e., not metal bonded) to a valence desirably closer to its maximum valence.Type: GrantFiled: April 25, 2017Date of Patent: October 18, 2022Assignees: Dow Global Technologies LLC, Georgia Tech Research CorporationInventors: Yu-Han Chu, William J. Koros, Liren Xu, Mark K. Brayden, Marcos V. Martinez
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Patent number: 11420154Abstract: The invention is an improved method of making an improved carbon molecular sieve (CMS) membrane in which a precursor polymer (e.g., polyimide) is pyrolyzed at a pyrolysis temperature to form a CMS membrane that is cooled to ambient temperature (about 40° C. or 30° C. to about 20° C.). The CMS membrane is then reheated to a reheating temperature less than the pyrolysis temperature to form the improved CMS membrane. The improved CMS membranes have shown an improved combination of selectivity and permeance as well as stability for separating hydrogen from gas molecules (e.g., methane, ethane, propane, ethylene, propylene, butane, carbon dioxide, nitrogen, butylene, and combinations thereof).Type: GrantFiled: April 3, 2019Date of Patent: August 23, 2022Assignees: Dow Global Technologies LLC, Georgia Tech Resarch CorporationInventors: Justin T. Vaughn, Wulin Qiu, William J. Koros, Liren Xu, Mark K. Brayden, Marcos V. Martinez
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Patent number: 11167248Abstract: An asymmetric hollow fiber (CMS) carbon molecular sieve is made by providing a dope solution comprised of a polvimide and a solvent, at a temperature greater than 250° C. that is less than the storage modulus at a temperature of 250° C., but no more than ten times less as measured using dynamic mechanical thermal analysis from 250° C. to a temperature where the polyimide carbonizes. The polvimide is shaped into a hollow polvimide fiber, the solvent removed and the polyimide hollow fiber is heated to pyroiyze the polvimide and form the asymmetric hollow carbon molecular sieve. The asymmetric hollow fiber carbon molecular sieve has a wall that is defined by an inner surface and outer surface of said fiber and the wall has an inner porous support region extending from the inner surface to an outer raicroporous separation region that extends from the inner porous support region to the outer surface.Type: GrantFiled: September 25, 2017Date of Patent: November 9, 2021Assignee: Dow Global Technologies LLCInventors: Liren Xu, Rahul Sharma, William J. Harris, Mark K. Brayden, Marcos V. Martinez
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Publication number: 20210324142Abstract: A cross-linked polyimide of the reaction product of a crosslinking agent and a polyimide. The cross-linking agent having at least two cross-linking moieties and the polyimide has a plurality of polyimide chains having an aryl constituent with a moiety comprised of a reactive substituent. The polyimide has crosslinks from the reaction of the reactive substituent of the aryl constituents of the polyimide chains and the cross-linking moieties of the cross-linking agent. The cross-linking may be induced by thermally treating a mixture of the polyimide and crosslinking agent above about 150° C. to a temperature where the polyimide begins to decompose under an inert atmosphere. The membrane can be used for separations involving gases such as hydrogen and light hydrocarbons.Type: ApplicationFiled: August 20, 2019Publication date: October 21, 2021Applicants: Dow Global Technologies LLC, Georgia Tech Research CorporationInventors: Justin T. Vaughn, Wulin Qiu, William J. Koros, Liren Xu, Mark K. Brayden
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Patent number: 11130098Abstract: The invention is an improved method of making a carbon molecular sieve (CMS) membrane in which a precursor polymer is pyrolyzed to form a carbon molecular sieve membrane that is then exposed to a conditioning atmosphere comprised of a target permeate gas molecule such as ethylene when the membrane is desired to separate it from a light hydrocarbon gas stream. The exposure to the ethylene desirably occurs prior to the CMS permeance and selectivity combination substantially changing (e.g., within 5 days) of cooling from the pyrolyzing temperature. The CMS membranes have shown an improved combination of selectivity and permeance as well as stability and are useful to separate gases in gas streams such methane from natural gas, oxygen from air and ethylene or propylene from light hydrocarbon streams.Type: GrantFiled: November 30, 2016Date of Patent: September 28, 2021Assignee: Dow Global Technologies LLCInventors: John Hessler, William J. Koros, Liren Xu, Mark K. Brayden, Marcos V. Martinez
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Patent number: 11084000Abstract: The invention is an improved method of making a carbon molecular sieve (CMS) membrane in which a polyimide precursor polymer is pyrolyzed to form a carbon molecular sieve membrane by heating, in a furnace, said polyimide precursor polymer to a final pyrolysis temperature of 600 C to 700 C at a pyrolysis heating rate of 3 to 7 C/minute from 400 C to the final pyrolysis temperature, the final pyrolysis temperature being held for a pyrolysis time of at most 60 minutes in a non-oxidizing atmosphere. In a particular embodiment, the cooling rate from the pyrolysis temperature is accelerated by methods to remove heat. The CMS membranes have shown an improved combination of selectivity and permeance as well as being particularly suitable to separate gases in gas streams such methane from natural gas, oxygen from air and ethylene or propylene from light hydrocarbon streams.Type: GrantFiled: March 2, 2017Date of Patent: August 10, 2021Assignees: Dow Global Technologies LLC, Georgia Tech Research CorporationInventors: John Hessler, William J. Koros, Liren Xu, Mark K. Brayden, Marcos V. Martinez
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Publication number: 20210229030Abstract: The invention is an improved method of making an improved carbon molecular sieve (CMS) membrane in which a precursor polymer (e.g., polyimide) is pyrolyzed at a pyrolysis temperature to form a CMS membrane that is cooled to ambient temperature (about 40° C. or 30° C. to about 20° C.). The CMS membrane is then reheated to a reheating temperature less than the pyrolysis temperature to form the improved CMS membrane. The improved CMS membranes have shown an improved combination of selectivity and permeance as well as stability for separating hydrogen from gas molecules (e.g., methane, ethane, propane, ethylene, propylene, butane, carbon dioxide, nitrogen, butylene, and combinations thereof).Type: ApplicationFiled: April 3, 2019Publication date: July 29, 2021Applicants: Dow Global Technologies LLC, Georgia Tech Research CorporationInventors: Justin T. Vaughn, Wulin Qiu, William J. Koros, Liren Xu, Mark K. Brayden, Marcos V. Martinez
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Publication number: 20210129085Abstract: The invention is an improved method of making an improved carbon molecular sieve (CMS) membrane in which a precursor polymer (e.g., polyimide) is pyrolyzed at a pyrolysis temperature to form a CMS membrane that is cooled to ambient temperature (about 40° C. or 30° C. to about 20° C.). The CMS membrane is then reheated to a reheating temperature of at least 250° C. to 400° C. to form the improved CMS membrane. The CMS have a novel microstructure as determined by Raman spectroscopy. The improved CMS membranes have shown an improved combination of selectivity and permeance as well as stability for separating light hydrocarbon gas molecules such as C1 to C6 hydrocarbon gases (e.g., methane, ethane, propane, ethylene, propylene, butane, butylene).Type: ApplicationFiled: April 3, 2019Publication date: May 6, 2021Applicants: Dow Global Technologies LLC, Georgia Tech Research CorporationInventors: Liren Xu, Thomas Fitzgibbons, Mark K. Brayden, Marcos V. Martinez, William J. Koros, Wulin Qiu
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Publication number: 20200276542Abstract: A carbon molecular sieve (CMS) membrane having improved separation characteristics for separating olefins from their corresponding paraffins is comprised of carbon with at most trace amounts of sulfur and a group 13 metal. The CMS membrane may be made by pyrolyzing a precursor polymer devoid of sulfur in which the precursor polymer has had a group 13 metal incorporated into it, wherein the metal is in a reduced state. The pyrolyzing for the precursor having the group 13 metal incorporated into it is performed in a nonoxidizing atmosphere and at a heating rate and temperature such that the metal in a reduced state (e.g., covalently bonded to carbon or nitrogen or in the metal state).Type: ApplicationFiled: June 8, 2018Publication date: September 3, 2020Applicants: Dow Global Technologies LLC, Georgia Tech Research CorporationInventors: Yu-Han Chu, William J. Koros, Liren Xu, Mark K. Brayden, Marcos V. Martinez
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Publication number: 20200254393Abstract: A method of making a hollow fiber carbon molecular sieve is comprised of heating a hollow polymer fiber to a carbonization temperature in an atmosphere that is non-oxidizing to form a hollow fiber carbon molecular sieve, wherein during at least a portion of the heating a tensile force is applied to the hollow polymer fiber. The method may improve the separation of gases similar in size such a propylene from propane.Type: ApplicationFiled: March 20, 2018Publication date: August 13, 2020Applicant: Dow Global Technologies LLCInventors: Liren Xu, Rahul Sharma, Thomas Fitzgibbons, Mark K. Brayden, Marcos V. Martinez
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Publication number: 20190275471Abstract: An asymmetric hollow fiber (CMS) carbon molecular sieve is made by providing a dope solution comprised of a polvimide and a solvent, at a temperature greater than 250° C. that is less than the storage modulus at a temperature of 250° C., but no more than ten times less as measured using dynamic mechanical thermal analysis from 250° C. to a temperature where the polyimide carbonizes. The polvimide is shaped into a hollow polvimide fiber, the solvent removed and the polyimide hollow fiber is heated to pyroiyze the polvimide and form the asymmetric hollow carbon molecular sieve. The asymmetric hollow fiber carbon molecular sieve has a wall that is defined by an inner surface and outer surface of said fiber and the wall has an inner porous support region extending from the inner surface to an outer raicroporous separation region that extends from the inner porous support region to the outer surface.Type: ApplicationFiled: September 25, 2017Publication date: September 12, 2019Inventors: Liren Xu, Rahul Sharma, William J. Harris, Mark K. Brayden, Marcos V. Martinez
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Publication number: 20190247806Abstract: A polyimide separation membrane is comprised of a polyimide, a halogen compound (e.g., halogenated aromatic epoxide) that is soluble in the polyimide and a hydrocarbon having 2 to 5 carbons (e.g., ethane, ethylene, propane or propylene). The gas separation membrane has improved selectivity for small gas molecules such as hydrogen compared to polyimide membrane not containing the halogen compound or hydrocarbon. The polyimide separation membrane may be made by shaping a dope solution comprised of a polyimide, a halogen containing compound that is soluble in the polyimide, removing the solvent and then exposing the untreated polyimide membrane to a treating atmosphere comprising a hydrocarbon having 2 to 5 carbons for a sufficient time to form the polyimide membrane.Type: ApplicationFiled: September 25, 2017Publication date: August 15, 2019Inventors: Liren Xu, Justin T. Vaughn, Wulin Qiu, William J. Koros, Mark K. Brayden, Marcos V. Martinez
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Publication number: 20190118133Abstract: A carbon molecular sieve (CMS) membrane having improved separation characteristics for separating olefins from their corresponding paraffins is comprised of carbon with at most trace amounts of sulfur and a transition metal, wherein the transition metal is one or more of a group 4-10 and 12 transition metal. The CMS membrane may be made by pyrolyzing a precursor polymer devoid of sulfur in which the precursor polymer has had a transition metal incorporated into it. The pyrolyzing for the precursor having the transition metal incorporated into it is performed in a nonoxidizing atmosphere and at a heating rate and temperature such that the metal has a valence greater than zero (i.e., not metal bonded) to a valence desirably closer to its maximum valence.Type: ApplicationFiled: April 25, 2017Publication date: April 25, 2019Inventors: Yu-Han Chu, William J. Koros, Liren Xu, Mark K. Brayden, Marcos V. Martinez
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Publication number: 20190099722Abstract: The invention is an improved method of making a carbon molecular sieve (CMS) membrane in which a polyimide precursor polymer is pyrolyzed to form a carbon molecular sieve membrane by heating, in a furnace, said polyimide precursor polymer to a final pyrolysis temperature of 600 C to 700 C at a pyrolysis heating rate of 3 to 7 C/minute from 400 C to the final pyrolysis temperature, the final pyrolysis temperature being held for a pyrolysis time of at most 60 minutes in a non-oxidizing atmosphere. In a particular embodiment, the cooling rate from the pyrolysis temperature is accelerated by methods to remove heat. The CMS membranes have shown an improved combination of selectivity and permeance as well as being particularly suitable to separate gases in gas streams such methane from natural gas, oxygen from air and ethylene or propylene from light hydrocarbon streams.Type: ApplicationFiled: March 2, 2017Publication date: April 4, 2019Inventors: John Hessler, William J. Koros, Liren Xu, Mark K. Brayden, Marcos V. Martinez
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Publication number: 20180369761Abstract: The invention is an improved method of making a carbon molecular sieve (CMS) membrane in which a precursor polymer is pyrolyzed to form a carbon molecular sieve membrane that is then exposed to a conditioning atmosphere comprised of a target permeate gas molecule such as ethylene when the membrane is desired to separate it from a light hydrocarbon gas stream. The exposure to the ethylene desirably occurs prior to the CMS permeance and selectivity combination substantially changing (e.g., within 5 days) of cooling from the pyrolyzing temperature. The CMS membranes have shown an improved combination of selectivity and permeance as well as stability and are useful to separate gases in gas streams such methane from natural gas, oxygen from air and ethylene or propylene from light hydrocarbon streams.Type: ApplicationFiled: November 30, 2016Publication date: December 27, 2018Inventors: John Hessler, William J. Koros, Liren Xu, Mark K. Brayden, Marcos V. Martinez