Including Distillation Patents (Class 570/178)
  • Patent number: 6863780
    Abstract: 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: Grant
    Filed: September 28, 2001
    Date of Patent: March 8, 2005
    Inventors: Tatsuo Nakada, Noriaki Shibata, Takashi Shibanuma
  • Patent number: 6849772
    Abstract: 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: Grant
    Filed: October 7, 2002
    Date of Patent: February 1, 2005
    Assignee: Solvay (Societe Anonyme)
    Inventors: Charles-Marie Anciaux, Vincent Wilmet, Dominique Lecroc
  • Patent number: 6849163
    Abstract: There is provided a process for recovering tetrafluoroethylene wherein an amount of energy required to obtain TFE is reduced.
    Type: Grant
    Filed: February 27, 2001
    Date of Patent: February 1, 2005
    Assignee: Daikin Industries, Ltd.
    Inventors: Shigeyuki Yoshii, Yukio Homoto
  • Patent number: 6844474
    Abstract: 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: Grant
    Filed: October 28, 1997
    Date of Patent: January 18, 2005
    Assignee: Allied Signal Inc.
    Inventors: Paul Gene Clemmer, Addison Miles Smith, Hsueh Sung Tung, John Stephen Bass
  • Patent number: 6794550
    Abstract: 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: Grant
    Filed: August 28, 2001
    Date of Patent: September 21, 2004
    Assignee: 3M Innovative Properties Company
    Inventors: Klaus Hintzer, Gernot Löhr, Albert Killich, Werner Schwertfeger
  • Publication number: 20040144637
    Abstract: 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: Application
    Filed: November 4, 2003
    Publication date: July 29, 2004
    Inventors: Gultekin Erdem, Morris Leckebusch, Gunter Olf, Kay-Jochen Rinck, Gunter Zuhlke
  • Patent number: 6759381
    Abstract: 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: Grant
    Filed: May 6, 2003
    Date of Patent: July 6, 2004
    Assignee: Honeywell International Inc.
    Inventors: Robert C. Johnson, Daniel C. Merkel, Hsuehsung Tung
  • Publication number: 20040073072
    Abstract: 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: Application
    Filed: July 18, 2003
    Publication date: April 15, 2004
    Inventors: John David Scott, Charles Brian Blake, Paul Nicholas Ewing, Jeremy Charles Bauser Hunns, Steven Toplis, Andrew Neil Irwin, Mark Spruce
  • Patent number: 6676809
    Abstract: 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: Grant
    Filed: November 12, 1997
    Date of Patent: January 13, 2004
    Assignee: Daikin Industries Ltd.
    Inventors: Takehide Tsuda, Takeo Matsumoto, Yoshinori Tanaka, Satoshi Komatsu, Satoshi Koyama
  • Patent number: 6673264
    Abstract: 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: Grant
    Filed: June 3, 2002
    Date of Patent: January 6, 2004
    Assignee: Honeywell International Inc.
    Inventors: Hang T. Pham, Rajiv R. Singh, Hsueh S. Tung
  • Patent number: 6660130
    Abstract: 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: Grant
    Filed: April 11, 2001
    Date of Patent: December 9, 2003
    Assignee: Ineos Fluor Holdings Limited
    Inventors: John David Scott, Charles Brian Blake, Paul Nicholas Ewing, Jeremy Charles Bauser Hunns, Steven Toplis, Andrew Neil Irwin, Mark Spruce
  • Patent number: 6646171
    Abstract: 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: Grant
    Filed: November 13, 2001
    Date of Patent: November 11, 2003
    Assignee: Amersham Health AS
    Inventor: Jan Cervenka
  • Patent number: 6642415
    Abstract: 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: Grant
    Filed: April 12, 2002
    Date of Patent: November 4, 2003
    Assignee: 3M Innovative Properties Company
    Inventors: Stephan Führer, Klaus Hintzer, Gernot Löhr, Werner Schwertfeger
  • Publication number: 20030164283
    Abstract: 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: Application
    Filed: February 14, 2002
    Publication date: September 4, 2003
    Inventors: Stephan M. Brandstater, Mitchel Cohn, Victoria E. Hedrick, Yuichi Iikubo
  • Patent number: 6605193
    Abstract: 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: Grant
    Filed: April 25, 2001
    Date of Patent: August 12, 2003
    Assignee: Atofina Chemicals, Inc.
    Inventor: John A. Wismer
  • Publication number: 20030121769
    Abstract: The invention relates to the purification of pentafluoroethane (F125) containing chloropentafluoroethane (F115) by liquid/liquid extraction or by extractive distillation.
    Type: Application
    Filed: September 16, 2002
    Publication date: July 3, 2003
    Inventors: Emmanuel Guiraud, Cathy Descamps
  • Patent number: 6555086
    Abstract: 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: Grant
    Filed: October 7, 1999
    Date of Patent: April 29, 2003
    Assignee: Ineos Fluor Holdings Limited
    Inventors: Paul Nicholas Ewing, Charles John Shields, Robert Elliott Low
  • Patent number: 6552238
    Abstract: 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: Grant
    Filed: August 31, 2001
    Date of Patent: April 22, 2003
    Assignee: Vulcan Chemicals
    Inventors: Eric L. Mainz, Richard L. Wilson
  • Patent number: 6540882
    Abstract: 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: Grant
    Filed: March 22, 2000
    Date of Patent: April 1, 2003
    Assignee: Solvay (Societe Anonyme)
    Inventors: Ferdinand Reif, Dominique Balthasart
  • Patent number: 6527917
    Abstract: 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: Grant
    Filed: March 20, 2000
    Date of Patent: March 4, 2003
    Assignee: Daikin Industries Ltd.
    Inventors: Satoru Kohno, Takashi Shibanuma
  • Publication number: 20030010618
    Abstract: 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: Application
    Filed: March 23, 2001
    Publication date: January 16, 2003
    Inventor: Paul G. Clemmer
  • Publication number: 20030009065
    Abstract: 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: Application
    Filed: June 3, 2002
    Publication date: January 9, 2003
    Inventors: Hang T. Pham, Rajiv R. Singh, Hsueh S. Tung
  • Patent number: 6500994
    Abstract: 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: Grant
    Filed: June 8, 2001
    Date of Patent: December 31, 2002
    Assignee: Solvay Fluor und Derivate GmbH
    Inventors: Carsten Brosch, Heinz Gress, Matthias Rieland
  • Patent number: 6488817
    Abstract: 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: Grant
    Filed: March 31, 1998
    Date of Patent: December 3, 2002
    Assignee: AlliedSignal Inc.
    Inventors: Charles Francis Swain, Rajiv Ratna Singh, Hang Thanh Pham
  • Publication number: 20020157938
    Abstract: 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: Application
    Filed: April 25, 2001
    Publication date: October 31, 2002
    Inventor: John A. Wismer
  • Publication number: 20020156331
    Abstract: 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: Application
    Filed: October 7, 1999
    Publication date: October 24, 2002
    Inventors: PAUL NICHOLAS EWING, CHARLES JOHN SHIELDS, ROBERT ELLIOTT LOW
  • Patent number: 6458249
    Abstract: 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: Grant
    Filed: November 9, 1998
    Date of Patent: October 1, 2002
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Ralph Newton Miller, Chien-Ping Chai Kao, Barry Asher Mahler
  • Patent number: 6414203
    Abstract: 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: Grant
    Filed: May 9, 2001
    Date of Patent: July 2, 2002
    Assignee: Asahi Glass Company, Limited
    Inventors: Hidekazu Okamoto, Keiichi Ohnishi
  • Patent number: 6407297
    Abstract: 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: Grant
    Filed: July 13, 2000
    Date of Patent: June 18, 2002
    Assignee: Ineos Fluor Holdings Limited
    Inventor: Paul Nicholas Ewing
  • Patent number: 6403849
    Abstract: A method for obtaining purified perfluorocarbon compositions, and purified compositions containing such perfluorocarbons.
    Type: Grant
    Filed: September 26, 2000
    Date of Patent: June 11, 2002
    Assignee: 3M Innovative Properties Company
    Inventors: Zai-Ming Qiu, Zhongxing Zhang
  • Patent number: 6375808
    Abstract: 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: Grant
    Filed: April 26, 1999
    Date of Patent: April 23, 2002
    Assignee: Daikin Industries Ltd.
    Inventors: Takehide Tsuda, Takashi Shibanuma, Yasufu Yamada
  • Publication number: 20020035300
    Abstract: 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: Application
    Filed: August 19, 1999
    Publication date: March 21, 2002
    Inventors: V.N. MALLIKARJUNA RAO, ALLEN CAPRON SIEVERT
  • Patent number: 6346172
    Abstract: 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: Grant
    Filed: April 13, 1999
    Date of Patent: February 12, 2002
    Assignee: Daikin Industries, Ltd.
    Inventors: Takehide Tsuda, Takashi Shibanuma
  • Patent number: 6340781
    Abstract: 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: Grant
    Filed: April 3, 1995
    Date of Patent: January 22, 2002
    Assignee: Imperial Chemical Industries PLC
    Inventors: Charles John Shields, Gary Goodyear
  • Publication number: 20020007099
    Abstract: 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: Application
    Filed: November 30, 1998
    Publication date: January 17, 2002
    Inventors: CHARLES-MARIE ANCIAUX, VINCENT WILMET, DOMINIQUE LECROC
  • Publication number: 20020001560
    Abstract: 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: Application
    Filed: November 9, 1998
    Publication date: January 3, 2002
    Inventors: RALPH NEWTON MILLER, BARRY ASHER MAHLER, CHIEN-PING CHAI KAO
  • Patent number: 6333440
    Abstract: 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: Grant
    Filed: April 4, 2001
    Date of Patent: December 25, 2001
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: V. N. Malikarjuna
  • Patent number: 6328907
    Abstract: 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: Grant
    Filed: July 23, 1998
    Date of Patent: December 11, 2001
    Assignee: Daikin Industries, Ltd.
    Inventors: Tatsuo Nakada, Noriaki Shibata, Takashi Shibanuma
  • Patent number: 6307115
    Abstract: 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: Grant
    Filed: November 13, 1997
    Date of Patent: October 23, 2001
    Inventors: Emmanuel Guiraud, Cathy Descamps
  • Patent number: 6303838
    Abstract: 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: Grant
    Filed: March 31, 2000
    Date of Patent: October 16, 2001
    Assignee: E.I. du Pont de Nemours and Company
    Inventors: Sara W. Boehmer, Barry Asher Mahler, Ralph Newton Miller
  • Patent number: 6294055
    Abstract: 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: Grant
    Filed: September 11, 1998
    Date of Patent: September 25, 2001
    Assignee: Solvay S.A.
    Inventors: Ralf Herkelmann, Carsten Brosch, Vincent Wilmet
  • Patent number: 6288294
    Abstract: 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: Grant
    Filed: March 6, 2001
    Date of Patent: September 11, 2001
    Assignee: Atofina Chemicals, Inc.
    Inventor: Michael S. Bolmer
  • Patent number: 6281396
    Abstract: 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: Grant
    Filed: August 11, 1995
    Date of Patent: August 28, 2001
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Leo Ernest Manzer, V. N. Mallikarjuna Rao
  • Publication number: 20010004961
    Abstract: 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: Application
    Filed: September 11, 1998
    Publication date: June 28, 2001
    Inventors: RALF HERKELMANN, CARSTEN BROSCH, VINCENT WILMET
  • Patent number: 6235161
    Abstract: 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: Grant
    Filed: November 25, 1997
    Date of Patent: May 22, 2001
    Assignee: Atofina Chemicals, Inc.
    Inventors: Richard M. Crooker, Maher Y. Elsheikh, Anthony D. Kelton, Morris P. Walker, Danny W. Wright
  • Patent number: 6221830
    Abstract: 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: Grant
    Filed: April 17, 1997
    Date of Patent: April 24, 2001
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Ralph Newton Miller, Mark Richard Deschere, Barry Asher Mahler, Olagappan Muthu
  • Patent number: 6179967
    Abstract: 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: Grant
    Filed: May 25, 1994
    Date of Patent: January 30, 2001
    Assignee: Showa Denko K.K.
    Inventors: Atsuo Nishimura, Reiji Takahashi
  • Patent number: 6175045
    Abstract: 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: Grant
    Filed: November 22, 1999
    Date of Patent: January 16, 2001
    Assignee: Daikin Industries Ltd.
    Inventors: Satoru Kohno, Takashi Shibanuma
  • Patent number: 6159346
    Abstract: 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: Grant
    Filed: November 25, 1997
    Date of Patent: December 12, 2000
    Assignee: Elf Atochem North America, Inc.
    Inventors: Richard M. Crooker, Maher Y. Elsheikh, Anthony D. Kelton, Morris P. Walker, Danny W. Wright
  • Patent number: 6156161
    Abstract: 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: Grant
    Filed: July 12, 1996
    Date of Patent: December 5, 2000
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Ralph Newton Miller