Patents by Inventor Barry Mahler
Barry Mahler 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: 20050016829Abstract: Disclosed is a distillation process for reducing the concentration of impurities dinitrogen difluoride and dinitrogen tetrafluoride in nitrogen trifluoride. The process comprises: (a) distilling a mixture comprising nitrogen trifluoride and dinitrogen difluoride and/or dinitrogen tetrafluoride in a distillation column in the presence of a compound having a higher normal boiling point than nitrogen trifluoride; (b) removing a mixture comprising dinitrogen difluoride and/or dinitrogen tetrafluoride as a sidedraw from the distillation column; (c) removing a mixture comprising the compound having a higher normal boiling point than nitrogen trifluoride from the bottom of the distillation column; and (d) removing a nitrogen trifluoride product having reduced concentration of dinitrogen difluoride and/or dinitrogen tetrafluoride from the top of the distillation column.Type: ApplicationFiled: April 7, 2004Publication date: January 27, 2005Inventors: Ralph Miller, Barry Mahler
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Patent number: 6635187Abstract: A process is disclosed for producing compositions including (a) a compound selected from the group consisting of CHF2CF3, CHF2CHF2, CH2FCF3, CH3CF3, CH3CHF2, CH2FCF2CHF2 and CHF2CF2CF2CHF2 and (b) at least one saturated halogenated hydrocarbon and/or ether having the formula: CnH2n+2-a-bClaFbOc wherein n is an integer from 1 to 4, a is an integer from 0 to 2n+1, b is an integer from 1 to 2n+2-a, and c is 0 or 1, provided that when c is 1 then n is an integer from 2 to 4, and provided that component (b) does not include the selected component (a) compound, wherein the molar ratio of component (b) to component (a) is between about 1:99 and a molar ratio of HF to component (a) in an azeotrope or azeotrope-like composition of component (a) with HF.Type: GrantFiled: November 15, 2000Date of Patent: October 21, 2003Assignee: E. I. du Pont de Nemours and CompanyInventors: Barry A. Mahler, V. N. Mallikarjuna Rao, Allen Capron Sievert
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Patent number: 6274781Abstract: A process for producing difluoromethane is disclosed which includes the step of contacting a gaseous mixture containing CH2Cl2 and hydrogen fluoride with a catalyst containing a catalytically effective amount of trivalent chromium supported on a carbon having an ash content of less than 0.5 percent by weight, at a temperature of from about 180 ° C. to about 375° C. The catalyst and temperature conditions of this process allow the concurrent reaction CCl3CF3 with HF to form CCl2FCF3. CH2ClF and unreacted CH2Cl2, each of which may be recovered as an azeotrope with HF, may be recycled.Type: GrantFiled: November 1, 1993Date of Patent: August 14, 2001Assignee: E. I. du Pont de Nemours and CompanyInventors: Paul S. Furmanek, David A. Glasscock, Michael Keane, Jr., Barry A. Mahler, V. N. Mallikarjuna Rao
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Patent number: 6224781Abstract: A process is disclosed for producing compositions including (a) a compound selected from the group consisting of CHF2CF3, CHF2CHF2, CH2FCF3, CH3CF3, CH3CHF2, CH2FCF2CHF2 and CHF2CF2CF2CHF2 and (b) at least one saturated halogenated hydrocarbon and/or ether having the formula: CnH2n+2−a−bClaFbOc wherein n is an integer from 1 to 4, a is an integer from 0 to 2n+1, b is an integer from 1 to 2n+2−a, and c is 0 or 1, provided that when c is 1 then n is an integer from 2 to 4, and provided that component (b) does not include the selected component (a) compound, wherein the molar ratio of component (b) to component (a) is between about 1:99 and a molar ratio of HF to component (a) in an azeotrope or azeotrope-like composition of component (a) with HF.Type: GrantFiled: August 20, 1998Date of Patent: May 1, 2001Assignee: E. I. du Pont de Nemours and CompanyInventors: Barry A. Mahler, V. N. Mallikarjuna Rao, Allen Capron Sievert, Munirpallam A. Subramanian, Edwin James Warwas
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Patent number: 6077819Abstract: A process is disclosed for recovering HF from a product mixture comprising HF and at least one compound having the formula CF.sub.3 CCl.sub.2+x F.sub.1-x (where x is 0 or 1). The process includes the steps of distilling the product mixture to remove all products which have a lower boiling point than the lowest boiling azeotrope containing HF and said at least one compound; and distilling said azeotrope to recover HF as an azeotropic composition containing HF and said at least one compound. Also disclosed are azeotrope and azeotrope-like compositions which consist essentially of hydrogen fluoride in combination with from about 10 to 27 mole percent CCl.sub.3 CF.sub.3 or from about 35 to 56 mole percent CCl.sub.2 FCF.sub.3.Type: GrantFiled: November 1, 1993Date of Patent: June 20, 2000Assignee: E. I. du Pont de Nemours and CompanyInventors: Barry A. Mahler, Ralph N. Miller, V. N. Mallikarjuna Rao
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Patent number: 5858066Abstract: An improved process is disclosed for separating and recovering a fluorocarbon and hydrogen chloride (HCl) from a gaseous fluorocarbon/HCl mixture, wherein the fluorocarbon and HCl are difficult to separate by conventional means because of the presence or potential formation of an azeotrope or azeotrope-like composition in the mixture, such process comprising using a semi-permeable membrane unit to form a fluorocarbon-depleted stream and a fluorocarbon-enriched stream which may then be further processed individually by distillation.Type: GrantFiled: May 21, 1997Date of Patent: January 12, 1999Assignee: E. I. du Pont de Nemours and CompanyInventors: William G. O'Brien, Barry A. Mahler
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Patent number: 5600040Abstract: Separation of CF.sub.3 CH.sub.2 F and CHF.sub.2 CHF.sub.2 from a mixture thereof is effectively achieved using either inorganic molecular sieves having suitable intermediate electronegaativities (compared to Zeolite Na-X) or activated carbon.Type: GrantFiled: February 17, 1995Date of Patent: February 4, 1997Assignee: E. I. Du Pont de Nemours and CompanyInventors: David R. Corbin, Barry A. Mahler
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Patent number: 5585529Abstract: Separation of CClF.sub.2 CF.sub.3 from CHF.sub.2 CF.sub.3 is effectively achieved using either acidic inorganic molecular sieves, non-acidic silicate molecular sieves, or activated carbon.Type: GrantFiled: November 28, 1995Date of Patent: December 17, 1996Assignee: E. I. Du Pont de Nemours and CompanyInventors: David R. Corbin, Michael P. Diebold, Barry A. Mahler
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Patent number: 5523499Abstract: A process is disclosed for purifying a hexafluoroethane product containing CClF.sub.3 and/or CHF.sub.3 impurities which comprises the step of contacting the product with a sorbent for said impurities selected from activated carbons and inorganic (i.e. zeolite) molecular sieves. Also disclosed is an improvement to a process for producing CF.sub.3 CF.sub.3 wherein CClF.sub.3 and/or CHF.sub.3 impurities are removed from the product utilizing said sorbents.Type: GrantFiled: December 28, 1994Date of Patent: June 4, 1996Assignee: E. I. Du Pont de Nemours and CompanyInventors: David R. Corbin, Richard E. Fernandez, Barry A. Mahler
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Patent number: 5470442Abstract: The disclosure relates to separating 1,1,2,2 tetrafluoroethane (HFC-134) and 1,1,1,2 tetrafluoroethane (HFC-134a) from each other and/or from fluorocarbon impurities by using extractive distillation with an extractive agent comprising an alcohol. Examples of suitable extractive agents comprise at least one member from the group of methanol, butanol, ethanol, propanol, their isomers and cyclic compounds thereof, among others.Type: GrantFiled: March 11, 1994Date of Patent: November 28, 1995Assignee: E. I. Du Pont de Nemours and CompanyInventors: Barry A. Mahler, Ralph N. Miller
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Patent number: 5421964Abstract: The present invention discloses an extractive distillation process for separating HCl from pentafluoroethane, chloropentafluoroethane, chlorotrifluoroethane, trifluoromethane, and other fully saturated and unsaturated fluorocarbons, chlorofluorocarbons and chlorocarbons.Type: GrantFiled: April 30, 1993Date of Patent: June 6, 1995Assignee: E. I. Du Pont de Nemours and CompanyInventors: Barry A. Mahler, Vinci M. Felix, Ralph N. Miller
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Patent number: 5399549Abstract: An improved process for the manufacture of CF.sub.3 CHF.sub.2 by contacting CF.sub.3 CHCl.sub.2 or CF.sub.3 CHClF with HF in the presence of a Cr.sub.2 O.sub.3 catalyst prepared by pyrolysis of ammonium dichromate, the reaction being conducted under controlled conditions whereby the production of CF.sub.3 CHF.sub.2 is maximized, and the formation of chloropentafluoroethane (CF.sub.3 CClF.sub.2) and other perhalo derivatives is minimized. The subject hydrogen-containing compound is useful as a blowing agent, propellant, refrigerant, fire extinguishing agent, or sterilant carrier gas.Type: GrantFiled: January 10, 1994Date of Patent: March 21, 1995Assignee: E. I. Du Pont de Nemours and CompanyInventors: Vinci M. Felix, William H. Gumprecht, Barry A. Mahler
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Patent number: 5334787Abstract: An improved process for the manufacture of CF.sub.3 CHF.sub.2 by contacting 1,2-dichloro-1,1,2-trifluoroethane (CClF.sub.2 CHClF) or 1-chloro-1,1,2,2-tetrafluoroethane (CHF.sub.2 CClF.sub.2) or mixtures of CF.sub.3 CHCl.sub.2 and CClF.sub.2 CHClF or mixtures of CF.sub.3 CHClF and CHF.sub.2 CClF.sub.2 with HF in the presence of a Cr.sub.2 O.sub.3 catalyst prepared by pyrolysis of ammonium dichromate, the reaction being conducted under controlled conditions whereby the production of CF.sub.3 CHF.sub.2 is maximized, and the formation of chloropentafluoroethane (CF.sub.3 CClF.sub.2) and other perhalo derivatives is minimized. The subject hydrogen-containing compound is useful as a blowing agent, propellant, refrigerant, fire extinguishing agent, or sterilant carrier gas.Type: GrantFiled: November 12, 1992Date of Patent: August 2, 1994Assignee: E. I. Du Pont de Nemours and CompanyInventors: Vinci M. Felix, William H. Gumprecht, Barry A. Mahler