Including Distillation Patents (Class 570/178)
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Patent number: 6863780Abstract: There is provided an azeotropic mixture having 1,1,1,3,3-pentafluoropropane and hydrogen fluoride. Further, there is provided a process of separating/purifying R-245fa and/or HF from a mixture of R-245fa and HF wherein the mixture of 1,1,1,3,3-pentafluoropropane and hydrogen fluoride is subjected to a distillation step so that a distillate is obtained which has the azeotropic mixture of 1,1,1,3,3-pentafluoropropane and hydrogen fluoride, and a bottom product is obtained which has separated/purified 1,1,1,3,3-pentafluoropropane or hydrogen fluoride.Type: GrantFiled: September 28, 2001Date of Patent: March 8, 2005Inventors: Tatsuo Nakada, Noriaki Shibata, Takashi Shibanuma
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Patent number: 6849772Abstract: 1,1-Difluoroethane containing less than 10 mg/kg of vinyl chloride is obtained by treatment, with hydrogen fluoride, of a crude 1,1-difluoroethane containing less than 1 mol of hydrogen chloride per mole of 1,1-difluoroethane.Type: GrantFiled: October 7, 2002Date of Patent: February 1, 2005Assignee: Solvay (Societe Anonyme)Inventors: Charles-Marie Anciaux, Vincent Wilmet, Dominique Lecroc
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Patent number: 6849163Abstract: There is provided a process for recovering tetrafluoroethylene wherein an amount of energy required to obtain TFE is reduced.Type: GrantFiled: February 27, 2001Date of Patent: February 1, 2005Assignee: Daikin Industries, Ltd.Inventors: Shigeyuki Yoshii, Yukio Homoto
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Patent number: 6844474Abstract: The present invention provides a vapor phase process for the production of difluoromethane, HFC-32. The process of this invention provides for the preparation of HFC-32 by a process that exhibits both good product yield and selectivity.Type: GrantFiled: October 28, 1997Date of Patent: January 18, 2005Assignee: Allied Signal Inc.Inventors: Paul Gene Clemmer, Addison Miles Smith, Hsueh Sung Tung, John Stephen Bass
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Patent number: 6794550Abstract: The invention provides a process for removing steam-volatile fluorinated emulsifiers in their free acid form, from aqueous fluoropolymer dispersions. The process comprises adding a nonionic emulsifier, to the aqueous fluoropolymer dispersion and, at a pH-value of the aqueous fluoropolymer dispersion below 5, removing steam-volatile fluorinated emulsifier by distillation until the concentration of steam-volatile fluorinated emulsifier in the dispersion reaches the desired value.Type: GrantFiled: August 28, 2001Date of Patent: September 21, 2004Assignee: 3M Innovative Properties CompanyInventors: Klaus Hintzer, Gernot Löhr, Albert Killich, Werner Schwertfeger
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Publication number: 20040144637Abstract: A process for the separation of dichlorobenzene mixtures containing m- and p-dichlorobenzene by means of extractive rectification using an extracting agent is described.Type: ApplicationFiled: November 4, 2003Publication date: July 29, 2004Inventors: Gultekin Erdem, Morris Leckebusch, Gunter Olf, Kay-Jochen Rinck, Gunter Zuhlke
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Patent number: 6759381Abstract: Provided are azeotropic and azeotrope-like mixtures of 1-chloro-1,3,3,3-tetrafluoropropane and 1,2-dichloro-3,3,3-trifluoropropene that are useful as an intermediate in the production of HFC-245fa. HFC-245fa is useful as a nontoxic, zero ozone depleting fluorocarbon useful as solvents, blowing agents, refrigerants, cleaning agents, aerosol propellants, heat transfer media, gaseous dielectrics, fire extinguishing compositions and power cycle working fluids.Type: GrantFiled: May 6, 2003Date of Patent: July 6, 2004Assignee: Honeywell International Inc.Inventors: Robert C. Johnson, Daniel C. Merkel, Hsuehsung Tung
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Publication number: 20040073072Abstract: Prior to carrying out a gaseous phase chemical reaction, a liquid phase organic compound which is prone to degrade is vaporised at elevated pressures with the aid of a second compound. In one embodiment of the invention, vaporisation is effected by co-vaporising a mixture of the two compounds in a vaporiser. In another embodiment, the first compound is injected into a hot gaseous stream and undergoes atomisation into droplets which then vaporise within the gaseous stream. The second compound is used to assist the atomisation process and/or to sweep atomised droplets of the first compound away from hot surfaces where the first compound would otherwise tend to undergo degradation if the droplets are allowed to reside in contact with such surfaces.Type: ApplicationFiled: July 18, 2003Publication date: April 15, 2004Inventors: John David Scott, Charles Brian Blake, Paul Nicholas Ewing, Jeremy Charles Bauser Hunns, Steven Toplis, Andrew Neil Irwin, Mark Spruce
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Patent number: 6676809Abstract: Hydrogen fluoride is effectively removed from a mixture of hydrogen fluoride, dichloromethane, chlorofluoromethane and/or difluoromethane by distilling the mixture so that two-component azeotropic mixtures of hydrogen fluoride and dichloromethane, hydrogen fluoride and chlorofluoromethane and hydrogen fluoride and difluoromethane are removed, or by liquid-separating the mixture into an upper liquid phase rich in hydrogen fluoride and a lower liquid phase not rich in hydrogen fluoride before each liquid phase is distilled as described above.Type: GrantFiled: November 12, 1997Date of Patent: January 13, 2004Assignee: Daikin Industries Ltd.Inventors: Takehide Tsuda, Takeo Matsumoto, Yoshinori Tanaka, Satoshi Komatsu, Satoshi Koyama
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Patent number: 6673264Abstract: The invention relates to azeotropic and azeotrope-like mixtures of 1,1,1,3,3-pentafluorobutane (HFC-365) and hydrogen fluoride and a process for separating the azeotrope-like mixtures. The compositions of the invention are useful as an intermediate in the production of HFC-365. The latter is useful as a nontoxic, zero ozone depleting fluorocarbon useful as a solvent, blowing agent, refrigerant, cleaning agent and aerosol to propellant.Type: GrantFiled: June 3, 2002Date of Patent: January 6, 2004Assignee: Honeywell International Inc.Inventors: Hang T. Pham, Rajiv R. Singh, Hsueh S. Tung
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Patent number: 6660130Abstract: Prior to carrying out a gaseous phase chemical reaction, a liquid phase organic compound which is prone to degrade is vaporized at elevated pressures with the aid of a second compound which together with the organic compound produces a mixture having a boiling point less than that of the organic compound. In one embodiment of the invention, vaporization is effected by co-vaporizing a mixture of the two compounds in a vaporiser. In another embodiment, the first compound is injected into a hot gaseous stream and undergoes atomization into droplets which then vaporize within the gaseous stream. The second compound is used to assist the atomization process and/or to sweep atomized droplets of the first compound away from hot surfaces where the first compound would otherwise tend to undergo degradation if the droplets are allowed to reside in contact with such surfaces.Type: GrantFiled: April 11, 2001Date of Patent: December 9, 2003Assignee: Ineos Fluor Holdings LimitedInventors: John David Scott, Charles Brian Blake, Paul Nicholas Ewing, Jeremy Charles Bauser Hunns, Steven Toplis, Andrew Neil Irwin, Mark Spruce
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Patent number: 6646171Abstract: A process for the crystallisation of a sterically hindered organic compound from a saturated or supersaturated solution of said compound in a solvent therefor, characterised in that crystallisation is effected under elevated pressure at a temperature above the boiling point of said solution at atmospheric pressure and up to the boiling point of said solution at said elevated pressure.Type: GrantFiled: November 13, 2001Date of Patent: November 11, 2003Assignee: Amersham Health ASInventor: Jan Cervenka
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Patent number: 6642415Abstract: Fluorinated emulsifiers, in particular, perfluorooctanoic acid are bound to anionic exchange resins for the purification of aqueous effluent from the production of fluoropolymers. Said emulsifiers may be quantitatively eluted from the exchanger with a water-miscible organic solvent, containing a small amount of ammonia. It is of advantage to distil off the ammonia containing solvent, recycle the emulsifier to a further polymerization and recycle the ammoniacal solvent for elution. Addition of alkalis improves the elution efficiency.Type: GrantFiled: April 12, 2002Date of Patent: November 4, 2003Assignee: 3M Innovative Properties CompanyInventors: Stephan Führer, Klaus Hintzer, Gernot Löhr, Werner Schwertfeger
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Publication number: 20030164283Abstract: The present invention involves processes that utilize an olefinic compound, in particular, hexafluoropropene (HFP) or chlorotrifluoroethene (CFC-1113) as extracting agents in the purification of pentafluoroethane (HFC-125). These processes can utilize recovered HFP as a precursor for the production of heptafluoropropane (HFC-227) or other derivatives.Type: ApplicationFiled: February 14, 2002Publication date: September 4, 2003Inventors: Stephan M. Brandstater, Mitchel Cohn, Victoria E. Hedrick, Yuichi Iikubo
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Patent number: 6605193Abstract: A method for isolating 32 from a crude mixture containing HCl and an azeotropic mixture of 32 and HF is provided without the need to isolate any HF azeotrope.Type: GrantFiled: April 25, 2001Date of Patent: August 12, 2003Assignee: Atofina Chemicals, Inc.Inventor: John A. Wismer
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Publication number: 20030121769Abstract: The invention relates to the purification of pentafluoroethane (F125) containing chloropentafluoroethane (F115) by liquid/liquid extraction or by extractive distillation.Type: ApplicationFiled: September 16, 2002Publication date: July 3, 2003Inventors: Emmanuel Guiraud, Cathy Descamps
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Patent number: 6555086Abstract: Processes for separating and recovering hydrogen fluoride from a gaseous mixture of an organic compound and hydrogen fluoride are disclosed. The processes include contacting the gaseous mixture with a solution of an alkali metal fluoride in hydrogen fluoride, separating a gas phase depleted in hydrogen fluoride and containing the organic compound from a liquid phase, and recovering hydrogen fluoride from the liquid phase.Type: GrantFiled: October 7, 1999Date of Patent: April 29, 2003Assignee: Ineos Fluor Holdings LimitedInventors: Paul Nicholas Ewing, Charles John Shields, Robert Elliott Low
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Patent number: 6552238Abstract: Provided is a method and system for separating heavy ends from a halogenated alkane in a waste stream. The method includes: (a) removing a bottom fraction containing heavy ends from a catalyst recovery unit and conveying the bottom fraction to a vessel; (b) introducing steam into the bottom fraction containing heavy ends; (c) removing a halogenated alkane vapor and a water vapor from the waste treatment unit; (d) condensing the halogenated alkane and water vapors; and (e) separating the halogenated alkane phase and water phase from the heavy ends.Type: GrantFiled: August 31, 2001Date of Patent: April 22, 2003Assignee: Vulcan ChemicalsInventors: Eric L. Mainz, Richard L. Wilson
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Patent number: 6540882Abstract: The invention relates to a process of separation of mixtures containing HFC-365mfc/HF azeotropic compositions by two distillations at different pressures, as well as to a process of synthesis of HFC-365mfc which integrates this process of separation and a recycling of certain fractions towards the hydrofluorination step.Type: GrantFiled: March 22, 2000Date of Patent: April 1, 2003Assignee: Solvay (Societe Anonyme)Inventors: Ferdinand Reif, Dominique Balthasart
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Patent number: 6527917Abstract: A method for efficiently separating pentafluoroethane (HFC-125) from a mixture thereof with chloropentafluoroethane (CFC-115). This method is performed by subjecting a mixture (2) of HFC-125 (6) and CFC-115 (4) to extractive distillation (1) to give highly concentrated HFC-125 (6). A hydrofluorocarbon compound (3) having two carbon atoms, particularly 1,1,1,2-tetrafluoroethane, is used as an extractant to obtain concentrated CFC-115 as a distillate and a mixture of HFC-125 having a reduced content of CFC-115 with the extractant as a bottom (5), the extractant being separated from HFC-124 in this mixture by distillation (9) and reused in the extractive distillation.Type: GrantFiled: March 20, 2000Date of Patent: March 4, 2003Assignee: Daikin Industries Ltd.Inventors: Satoru Kohno, Takashi Shibanuma
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Publication number: 20030010618Abstract: A method for separating difluoromethane from a mixture of said difluoromethane and at least one impurity, said method comprising extractively distilling said mixture using dichloromethane as the extractive agent to recover a product stream of purified difluoromethane having a concentration of said impurity lower than that of said mixture.Type: ApplicationFiled: March 23, 2001Publication date: January 16, 2003Inventor: Paul G. Clemmer
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Publication number: 20030009065Abstract: The invention relates to azeotropic and azeotrope-like mixtures of 1,1,1,3,3-pentafluorobutane (HFC-365) and hydrogen fluoride and a process for separating the azeotrope-like mixtures. The compositions of the invention are useful as an intermediate in the production of HFC-365. The latter is useful as a nontoxic, zero ozone depleting fluorocarbon useful as a solvent, blowing agent, refrigerant, cleaning agent and aerosol to propellant.Type: ApplicationFiled: June 3, 2002Publication date: January 9, 2003Inventors: Hang T. Pham, Rajiv R. Singh, Hsueh S. Tung
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Patent number: 6500994Abstract: A process for purification of 1,1,1,3,3-pentafluorobutane (HFC-365mfc) containing a decreased amount of hydrogen chloride, hydrogen fluoride and/or unsaturated impurities. To this end crude 1,1,1,3,3-pentafluorobutane is treated in the liquid phase with a solid, inorganic sorption agent and/or with diatomic molecules which and to C—C multiple bonds. The product to be purified is preferably treated with elemental fluorine. The contents of hydrogen chloride and hydrogen can each be decreased to below 1 ppm. The content of unsaturated (chlorine)-fluorine-compounds can be decreased to below 20 ppm, and the content of unsaturated C2 compounds can be decreased to below 10 ppm. It has also been discovered that fluorotrichloroethylene can be used as a control substance to monitor the purification of 1,1,1,3,3-pentafluorobutane.Type: GrantFiled: June 8, 2001Date of Patent: December 31, 2002Assignee: Solvay Fluor und Derivate GmbHInventors: Carsten Brosch, Heinz Gress, Matthias Rieland
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Patent number: 6488817Abstract: A process for the purification of difluoromethane comprising: (a) subjecting a mixture comprising at least difluoromethane (HFC-32) and dichlorodifluoromethane (CFC-12) to a first distillation step in which a majority of either CFC-12 or HFC-32 is concentrated in a first distillate and a majority of the other component is concentrated in a first bottoms; and (b) subjecting the first distillate in step (a) to at least one additional second distillation step conducted at a different pressure in which a majority of the component concentrated in said first distillate is concentrated in a second bottoms and in which the other component is concentrated in a second distillate; and (c) recovering purified HFC-32 from one of said first or second bottoms.Type: GrantFiled: March 31, 1998Date of Patent: December 3, 2002Assignee: AlliedSignal Inc.Inventors: Charles Francis Swain, Rajiv Ratna Singh, Hang Thanh Pham
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Publication number: 20020157938Abstract: A method for isolating 32 from a crude mixture containing HCl and an azeotropic mixture of 32 and HF is provided without the need to isolate any HF azeotrope.Type: ApplicationFiled: April 25, 2001Publication date: October 31, 2002Inventor: John A. Wismer
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Publication number: 20020156331Abstract: A process for recovery of hydrogen fluoride comprises contacting a gaseous mixture containing hydrogen fluoride and an organic compound with a solution of an alkali metal fluoride in hydrogen fluoride, separating a gas phase depleted in hydrogen fluoride and containing the organic compound from a liquid phase enriched in hydrogen fluoride, and then recovering the hydrogen fluoride from the liquid phase.Type: ApplicationFiled: October 7, 1999Publication date: October 24, 2002Inventors: PAUL NICHOLAS EWING, CHARLES JOHN SHIELDS, ROBERT ELLIOTT LOW
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Patent number: 6458249Abstract: Nitrogen trifluoride (NF3) containing less than 10 parts-per-million molar impurities, e.g., tetrafluoromethane (PFC-14), is disclosed. Azeotropic and extractive distillation processes using entraining agents for separating NF3 and PFC-14 from each other and from mixtures with other electronics industry materials are disclosed.Type: GrantFiled: November 9, 1998Date of Patent: October 1, 2002Assignee: E. I. du Pont de Nemours and CompanyInventors: Ralph Newton Miller, Chien-Ping Chai Kao, Barry Asher Mahler
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Patent number: 6414203Abstract: A method for reducing the content of unsaturated impurities contained in 1,1,1,3,3-pentafluoropropane (R245fa), while maintaining the loss of R245fa at a minimum level. R245fa containing unsaturated impurities is contacted in a gas phase with chlorine gas in the presence of an activated carbon catalyst, thereby converting the unsaturated impurities to the chlorine addition compounds to reduce the content of the unsaturated impurities.Type: GrantFiled: May 9, 2001Date of Patent: July 2, 2002Assignee: Asahi Glass Company, LimitedInventors: Hidekazu Okamoto, Keiichi Ohnishi
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Patent number: 6407297Abstract: Preparation of a fluorine-containing organic compound by reacting a haloalkene with hydrogen fluoride wherein both the fluorine-containing organic compound and the haloalkene separately form azeotropes with hydrogen fluoride and wherein the haloalkene/hydrogen fluoride azeotrope is more volatile than the fluorine-containing organic compound/hydrogen fluoride azeotrope.Type: GrantFiled: July 13, 2000Date of Patent: June 18, 2002Assignee: Ineos Fluor Holdings LimitedInventor: Paul Nicholas Ewing
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Patent number: 6403849Abstract: A method for obtaining purified perfluorocarbon compositions, and purified compositions containing such perfluorocarbons.Type: GrantFiled: September 26, 2000Date of Patent: June 11, 2002Assignee: 3M Innovative Properties CompanyInventors: Zai-Ming Qiu, Zhongxing Zhang
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Patent number: 6375808Abstract: A process for refining difluoromethane by removing hydrogen fluoride, which is contained in difluoromethane difficult to remove. The process involves distilling a mixture of difluoromethane with hydrogen fluoride where the mixture is in contact with sulfuric acid. The hydrogen fluoride remains in the liquid phase and the difluoromethane goes into the vapor phase.Type: GrantFiled: April 26, 1999Date of Patent: April 23, 2002Assignee: Daikin Industries Ltd.Inventors: Takehide Tsuda, Takashi Shibanuma, Yasufu Yamada
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Publication number: 20020035300Abstract: A process is disclosed for producing the pentafluoropropenes of the formula CF 3 CX═CF 2 , where X is H or Cl. The process involves hydrodehalogenating CF 3 CCl 2 CF 3 with hydrogen at an elevated temperature in the vapor phase over a catalyst comprising an elemental metal, metal oxide, metal halide and/or metal oxyhalide (the metal being copper, nickel, chromium and the halogen of said halides and said oxyhalides being fluorine and/or chlorine).Type: ApplicationFiled: August 19, 1999Publication date: March 21, 2002Inventors: V.N. MALLIKARJUNA RAO, ALLEN CAPRON SIEVERT
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Patent number: 6346172Abstract: A process for refining difluoromethane by removing water which is contained in difluoromethane and has been believed to be difficult to be removed includes distilling difluoromethane which contains water so as to obtain difluoromethane as a distillate and a mixture as a bottom product of difluoromethane and chlorofluoromethane and/or dichloromethane which mixture contains water. The bottom product is recycled to a reaction step to be reused together with a feedstock.Type: GrantFiled: April 13, 1999Date of Patent: February 12, 2002Assignee: Daikin Industries, Ltd.Inventors: Takehide Tsuda, Takashi Shibanuma
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Patent number: 6340781Abstract: A process for the removal of chloroalkane, chlorofluoroalkane and/or hydrofluoroalkane impurities from pentafluoroethane which comprises contacting the impure pentafluoroethane with hydrogen at elevated temperature in the presence of a hydrogenation catalyst to convert the impurity or impurities to a hydrofluoroalkane and/or a hydrocarbon and separating the resulting hydrofluoroalkane and/or hydrocarbon from the pentafluoroethane.Type: GrantFiled: April 3, 1995Date of Patent: January 22, 2002Assignee: Imperial Chemical Industries PLCInventors: Charles John Shields, Gary Goodyear
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Publication number: 20020007099Abstract: 1,1-Difluoroethane containing less than 10 mg/kg of vinyl chloride is obtained by treatment, with hydrogen fluoride, of a crude 1,1-difluoroethane containing less than 1 mol of hydrogen chloride per mole of 1,1-difluoroethane.Type: ApplicationFiled: November 30, 1998Publication date: January 17, 2002Inventors: CHARLES-MARIE ANCIAUX, VINCENT WILMET, DOMINIQUE LECROC
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Publication number: 20020001560Abstract: Nitrogen trifluoride (NF3) containing less than 10 parts-per-million molar impurities, e.g., tetrafluoromethane (PFC-14), is disclosed. Azeotropic and extractive distillation processes using entraining agents for separating NF3 and PFC-14 from each other and from mixtures with other electronics industry materials are disclosed.Type: ApplicationFiled: November 9, 1998Publication date: January 3, 2002Inventors: RALPH NEWTON MILLER, BARRY ASHER MAHLER, CHIEN-PING CHAI KAO
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Patent number: 6333440Abstract: A process is disclosed for obtaining octafluorocyclobutane of increased purity from a mixture comprising (a) octafluorocyclobutane and (b) at least one halocarbon impurity which is difficult to separate from octafluorocyclobutane by distillation (e.g., azeotropes of octafluorocyclobutane with such halocarbons). The process involves (1) contacting the mixture with a catalyst in the vapor phase in the presence HCl and/or HF at a temperature sufficient to react component (b) impurity with HCl and/or HF to provide a product mixture comprising halogenated product which is more easily separated from octafluorocyclobutane by distillation than the unreacted impurity; and (2) separating halogenated product obtained in (1) from octafluorocyclobutane by distillation.Type: GrantFiled: April 4, 2001Date of Patent: December 25, 2001Assignee: E. I. du Pont de Nemours and CompanyInventor: V. N. Malikarjuna
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Patent number: 6328907Abstract: There is provided an azeotropic mixture consisting substantially of 1,1,1, 3,3-pentafluoropropane and hydrogen fluoride. Further, there is provided a process of separating/purifying R-245fa and/or HF from a mixture comprising R-245fa and HF wherein the mixture comprising 1,1,1,3,3-pentafluoropropane and hydrogen fluoride is subjected to a distillation step so that a distillate is obtained which comprises the azeotropic mixture consisting substantially of 1,1,1,3,3-pentafluoropropane and hydrogen fluoride, and a bottom product is obtained which comprises separated/purified 1,1,1,3,3-pentafluoropropane or hydrogen fluoride.Type: GrantFiled: July 23, 1998Date of Patent: December 11, 2001Assignee: Daikin Industries, Ltd.Inventors: Tatsuo Nakada, Noriaki Shibata, Takashi Shibanuma
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Patent number: 6307115Abstract: The invention relates to the purification of pentafluoroethane (F125) containing chloropentafluoroethane (F115) by liquid/liquid extraction or by extractive distillation. Perchloroethylene is used as extraction agent.Type: GrantFiled: November 13, 1997Date of Patent: October 23, 2001Inventors: Emmanuel Guiraud, Cathy Descamps
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Patent number: 6303838Abstract: Disclosed are processes for separating 1,1,1,3,3-pentafluoropropane (HFC-245fa) from hydrogen fluoride (HF) by distillation, wherein hydrocarbons, chloroflurocarbons, hydrochlorofluorocarbons and fluorocarbons are used as entraining agents. The processes comprise: contacting a first mixture comprising HFC-245fa and HF with an entraining agent selected from the group consisting of hydrocarbons, chlorofluorocarbons, hydrochlorofluorocarbons and fluorocarbons to form a second mixture, distilling the second mixture and thereby separating the HFC-245fa from HF and entraining agent, and recovering HFC-245fa substantially-free of HF.Type: GrantFiled: March 31, 2000Date of Patent: October 16, 2001Assignee: E.I. du Pont de Nemours and CompanyInventors: Sara W. Boehmer, Barry Asher Mahler, Ralph Newton Miller
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Patent number: 6294055Abstract: Process for the separation of hydrogen fluoride from its mixtures with a hydrofluoroalkane containing from 3 to 6 carbon atoms, by extraction using an organic solvent.Type: GrantFiled: September 11, 1998Date of Patent: September 25, 2001Assignee: Solvay S.A.Inventors: Ralf Herkelmann, Carsten Brosch, Vincent Wilmet
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Patent number: 6288294Abstract: A method for purifying a 133a product mixture containing olefinic impurities is provided wherein the mixture is contacted with a diene under conditions sufficient to convert the olefinic impurities to cyclohexenes.Type: GrantFiled: March 6, 2001Date of Patent: September 11, 2001Assignee: Atofina Chemicals, Inc.Inventor: Michael S. Bolmer
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Patent number: 6281396Abstract: A halocarbon product made from the reaction of excess hydrogen fluoride with a halocarbon, containing excess hydrogen fluoride as an azeotrope is purified by fluorination in the presence of additional halocarbon or halo-olefin.Type: GrantFiled: August 11, 1995Date of Patent: August 28, 2001Assignee: E. I. du Pont de Nemours and CompanyInventors: Leo Ernest Manzer, V. N. Mallikarjuna Rao
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Publication number: 20010004961Abstract: Process for the separation of hydrogen fluoride from its mixtures with a hydrofluoroalkane containing from 3 to 6 carbon atoms, by extraction using an organic solvent.Type: ApplicationFiled: September 11, 1998Publication date: June 28, 2001Inventors: RALF HERKELMANN, CARSTEN BROSCH, VINCENT WILMET
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Patent number: 6235161Abstract: Inhibition of the formation of unsaturated carbon compounds during the heating of 141b involving the addition of various inhibitors such as butylene oxide and/or the use of a vessel made of a nickel alloy.Type: GrantFiled: November 25, 1997Date of Patent: May 22, 2001Assignee: Atofina Chemicals, Inc.Inventors: Richard M. Crooker, Maher Y. Elsheikh, Anthony D. Kelton, Morris P. Walker, Danny W. Wright
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Patent number: 6221830Abstract: The disclosure relates to removing impurities from hexafluoroethane (CF3CF3), also known as Perfluorocarbon 116 (PFC-116) or Fluorocarbon 116 (FC-116), by using azeotropic distillation such that an overhead product consisting essentially of HCl-hexafluoroethane is formed, optionally combined with a phase separation step to break the HCl-hexafluoroethane azeotropic or azeotrope-like composition thereby permitting recovery of substantially pure hexafluoroethane. Unreacted hydrogen fluoride (HF) may be removed from hexafluoroethane during the above azeotropic distillation with HCl or alternatively by an azeotropic distillation wherein an HF-hexafluoroethane azeotropic or azeotrope-like composition exits overhead and substantially pure HF exits in the bottoms stream.Type: GrantFiled: April 17, 1997Date of Patent: April 24, 2001Assignee: E. I. du Pont de Nemours and CompanyInventors: Ralph Newton Miller, Mark Richard Deschere, Barry Asher Mahler, Olagappan Muthu
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Patent number: 6179967Abstract: A purification process of pentafluoroethane from a crude pentafluoroethane containing chloropentafluoroethane as a by-product by extractive distillation using an extracting reagent having a standard boiling point of from −10° C. to 100° C. and being selected from paraffinic hydrocarbons, alcohols, ethers, esters, and ketones.Type: GrantFiled: May 25, 1994Date of Patent: January 30, 2001Assignee: Showa Denko K.K.Inventors: Atsuo Nishimura, Reiji Takahashi
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Patent number: 6175045Abstract: There is provided a process of effectively separating pentafluoroethane (HFC-125) from a mixture of HFC-125 and chloropentafluoroethane (CFC-115). When the mixture of HFC-125 and CFC-115 is subjected to an extractive distillation to obtain a concentrated HFC-125, ethyleneglycol-based compounds (3) having a general formula: R1O(CH2CH2O)nR2 wherein R1 and R2 may be the same or different and are each independently selected from the group consisting of hydrogen and an alkyl group having 1 to 4 carbon atoms, and n is an integer with a value from 1 to 3 is used as an extractant, whereby CFC-115 is obtained as a distillate product (4) and a mixture of HFC-125 and the extractant as a bottom product (5) is obtained. Then, the extractant is separated from HFC-125 by distilling the mixture and re-used in the extractive distillation.Type: GrantFiled: November 22, 1999Date of Patent: January 16, 2001Assignee: Daikin Industries Ltd.Inventors: Satoru Kohno, Takashi Shibanuma
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Patent number: 6159346Abstract: Inhibition of the formation of unsaturated carbon compounds during the heating of 141b involving the addition of various inhibitors such as dialkylhydroxylamine and/or the use of a vessel made of a nickel alloy.Type: GrantFiled: November 25, 1997Date of Patent: December 12, 2000Assignee: Elf Atochem North America, Inc.Inventors: Richard M. Crooker, Maher Y. Elsheikh, Anthony D. Kelton, Morris P. Walker, Danny W. Wright
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Patent number: 6156161Abstract: A process is disclosed for removing chloropentafluoroethane (CFC-115) from a mixture comprising CFC-115, difluoromethane (HFC-32), pentafluoroethane (HFC-125), or from mixtures of these compounds, by azeotropic or extractive distillation.Type: GrantFiled: July 12, 1996Date of Patent: December 5, 2000Assignee: E. I. du Pont de Nemours and CompanyInventor: Ralph Newton Miller