Including Distillation Patents (Class 570/178)
  • Patent number: 6120652
    Abstract: The invention relates to a method for purifying a crude 1,1,1,3,3-pentafluoropropane (HFC-245fa) containing HFC-245fa and 1-chloro-3,3,3-trifluoro-trans-1-propene (HCFC-1233zd(t)), by distillation. This method is characterized in that the distillation is conducted in the presence of a solvent having a boiling point which is higher than that of HCFC-1233zd(t), thereby to substantially remove HCFC-1233zd(t) from the crude HFC-245fa. This solvent may be selected from carbon chlorides, chlorohydrocarbons, fluorochlorohydrocarbons, saturated hydrocarbons, and mixtures thereof. With the use of this solvent, it becomes possible to substantially easily separate HFC-245fa from HCFC-1233zd(t).
    Type: Grant
    Filed: March 10, 1998
    Date of Patent: September 19, 2000
    Assignee: Central Glass Company
    Inventors: Yasuo Hibino, Ryouichi Tamai
  • Patent number: 6107267
    Abstract: A process is disclosed for recovering HF from a product mixture including HF and CF.sub.3 CF.sub.2 CHF.sub.2. The process involves (1) distilling the product mixture to remove all products which have a lower boiling point than the lowest boiling azeotrope containing HF and CF.sub.3 CF.sub.2 CHF.sub.2 ; and (2) distilling the azeotrope to recover HF as an azeotropic composition containing HF and CF.sub.3 CF.sub.2 CHF.sub.2. Also disclosed are compositions of hydrogen fluoride in combination with an effective amount of CF.sub.3 CF.sub.2 CHF.sub.2 to form an azeotrope or azeotrope-like composition with hydrogen fluoride, (e.g., compositions containing from about 57.1 to 67.2 mole percent CF.sub.3 CF.sub.2 CHF.sub.2).A process for producing certain compositions comprising(a) CF.sub.3 CF.sub.2 CHF.sub.2 and (b) at least one saturated halogenated hydrocarbon and/or ether having the formula:C.sub.n H.sub.2n+2-a-b Cl.sub.a F.sub.b O.sub.
    Type: Grant
    Filed: August 20, 1998
    Date of Patent: August 22, 2000
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: V. N. Mallikarjuna Rao, Allen Capron Sievert, Munirpallam A. Subramanian
  • Patent number: 6099694
    Abstract: The invention relates to an improvement in a process in which chlorine and difluoromethane are present in a distillation column, for example, a fluorination reaction. By controlling the chlorine feed such that the concentration of chlorine relative to difluoromethane in the distillation column is maintained below about 22 weight percent (the flammability threshold for chlorine in a mixture of difluoromethane and chlorine), formation of a flammable difluoromethane/chlorine mixture may be minimized or avoided. The invention is particularly useful in a process for the preparation of difluoromethane wherein at least one distillation column separates difluoromethane from unreacted starting materials such as methylene chloride, hydrogen fluoride and monochloromonofluoromethane.
    Type: Grant
    Filed: March 23, 1998
    Date of Patent: August 8, 2000
    Assignee: AlliedSignal Inc.
    Inventors: Hang Thanh Pham, Rajiv R. Singh, Addison M. Smith, David P. Wilson, Raymond Hilton Percival Thomas, Gustavo Cerri
  • Patent number: 6060629
    Abstract: Provided are azeotropic and azeotrope-like mixtures of 1,1,1,3,3-pentafluoropropane (HFC-245fa) and hydrogen fluoride. Such are useful as an intermediate in the production of HFC-245fa. The latter is useful as a nontoxic, zero ozone depleting fluorocarbon useful as a solvent, blowing agent, refrigerant, cleaning agent, aerosol propellant, heat transfer medium, dielectric, fire extinguishing composition and power cycle working fluid.
    Type: Grant
    Filed: September 10, 1999
    Date of Patent: May 9, 2000
    Assignee: AlliedSignal Inc.
    Inventors: Hang Thanh Pham, Rajiv Ratna Singh, Ian Robert Shankland, Hsueh Sung Tung
  • Patent number: 6059933
    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: April 25, 1995
    Date of Patent: May 9, 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: 6047560
    Abstract: A process for separating pentafluoroethane and 1,1,1-trifluoroethane, which comprises extraction distilling a mixed fluid comprising pentafluoroethane and 1,1,1-trifluoroethane in the presence of at least one extracting agent selected from the group consisting of esters and ketones each having a standard boiling point of from -10.degree. C. to 100.degree. C. Also disclosed is a process for separating pentafluoroethane, 1,1,1-trifluoroethane and chloropentafluoroethane, which comprises extraction distilling a mixed fluid comprising pentafluoroethane, 1,1,1-trifluoroethane and chloropentafluoroethane in the presence of at least one extracting agent selected from the group consisting of esters and ketones each having a standard boiling point of from -10.degree. C. to 100.degree. C.
    Type: Grant
    Filed: March 12, 1998
    Date of Patent: April 11, 2000
    Assignee: Showa Denko K.K.
    Inventors: Atsuo Nishimura, Toshio Nagayasu, Reiji Takahashi
  • Patent number: 6039845
    Abstract: A process for the purification of pentafluoroethane (F125) containing chloropentafluoroethane (F115). The F125-F115 mixture to be purified is subjected to an extractive distillation, the extractant being a C.sub.5 -C.sub.8 perfluoroalkyl halide.
    Type: Grant
    Filed: January 2, 1998
    Date of Patent: March 21, 2000
    Assignee: Elf Atochem S.A.
    Inventors: Rene Bertocchio, Eric Lacroix, Sylvain Perdrieux
  • Patent number: 5948381
    Abstract: The invention provides a process for separating fluorinated organic compounds from mixtures of the such compounds and hydrogen fluoride. More particularly, the invention provides a method for separating a fluorinated organic compound from a mixture containing at least one fluorinated organic compound and hydrogen fluoride by adding an inorganic salt to the mixture.
    Type: Grant
    Filed: July 3, 1996
    Date of Patent: September 7, 1999
    Assignee: AlliedSignal Inc.
    Inventors: Richard Elmer Eibeck, Hang Thanh Pham, Valentine Theodore Zuba
  • Patent number: 5928479
    Abstract: A process for the purification of pentafluoroethane by removing chloropentafluoroethane therefrom which comprises adding to the impure pentafluoroethane a component which undergoes a non-ideal interaction with chloropentafluoroethane and/or with the azeotrope of chloropentafluoroethane and pentafluoroethane such that the volatility of chloropentafluoroethane and/or the azeotrope of chloropentafluoroethane and pentafluoroethane relative to bulk pentafluoroethane is increased and distilling the mixture.
    Type: Grant
    Filed: September 19, 1996
    Date of Patent: July 27, 1999
    Assignee: Imperial Chemical Industries PLC
    Inventors: Paul Nicholas Ewing, Stuart Corr, John Stuart Martin, Michael John Watson
  • Patent number: 5922175
    Abstract: A process for the purification of 1-chloro-1,2,2,2-tetrafluoroethane (F124) containing 1,2-dichlorotetrafluoroethane (F114) and/or 1,1-dichlorotetrafluoroethane (F114a). The F124 to be purified is subjected to extractive distillation, the extractant being chosen from C.sub.5 -C.sub.8 aliphatic or cycloaliphatic hydrocarbons and C.sub.4 -C.sub.8 perfluoroalkyl halides.
    Type: Grant
    Filed: January 30, 1998
    Date of Patent: July 13, 1999
    Assignee: ELF Atochem S.A.
    Inventors: Rene Bertocchio, Eric Deslandes, Eric Lacroix
  • Patent number: 5919340
    Abstract: There is provided a process of effectively separating pentafluorethane (HFC-125) out of a mixture of HFC and chloropentafluoroethane (CFC-115). When the mixture of HFC-125 and CFC-115 is subjected to extractive distillation so as to obtain concentrated HFC-125, methanol, ethanol, butanol, propyl alcohol, pentafluoropropanol, tetrafluoropropanol or acetone is used as an extractant, whereby CFC-115 is obtained as a distillate product and a mixture of HFC-125 and the extractant is separated from HFC-125 by distilling the mixture and re-used in the extractive distillation.
    Type: Grant
    Filed: February 14, 1997
    Date of Patent: July 6, 1999
    Assignee: Daikin Industries Ltd.
    Inventors: Satoru Kohno, Takashi Shibanuma
  • Patent number: 5874657
    Abstract: The present invention relates to processes for separating 1,1-difluoroethane (HFC-152a) from vinyl chloride by using extractive distillation with an extractive agent selected from the aliphatic hydrocarbons, chlorocarbons and alcohols.
    Type: Grant
    Filed: October 29, 1997
    Date of Patent: February 23, 1999
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Ralph Newton Miller, Barry Asher Mahler
  • Patent number: 5866730
    Abstract: A process is disclosed for enriching the amount of CFC-114 relative to the amount of CFC-114a from an initial mixture containing both isomers, by contacting said initial mixture with hydrogen chloride in the vapor phase at an elevated temperature in the presence of a catalyst to produce a product mixture containing C.sub.2 Cl.sub.2 F.sub.3 and chlorination products of CCl.sub.2 FCF.sub.3 wherein the weight ratio of CClF.sub.2 CClF.sub.2 to the total C.sub.2 Cl.sub.2 F.sub.4 is higher than the weight ratio of CClF.sub.2 CClF.sub.2 to the total C.sub.2 Cl.sub.2 F.sub.4 in the initial mixture. The chlorination products of CFC-114a (e.g., CCl.sub.3 CF.sub.3) in the product mixture may then be separated from the C.sub.2 Cl.sub.2 F.sub.4 therein (e.g., by distillation).
    Type: Grant
    Filed: April 2, 1993
    Date of Patent: February 2, 1999
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: V. N. Mallikarjuna Rao
  • Patent number: 5856595
    Abstract: A 1,1,1,3,3,3-hexafluoropropane product of greater than about 99.9 weight percent purity containing less than about 100 parts per million unsaturated fluorocarbons and a method for its purification from a distillation mixture of 1,1,1,3,3,3-hexafluoropropane with at least one unsaturated fluorocarbon which method includes the steps of:a) reacting the mixture with chlorine to saturate the unsaturated fluorocarbons,b) washing the reacted mixture with an aqueous solution to remove residual hydrochloric acid and chlorine,c) removing the aqueous solution, andd) distilling the reacted mixture to obtain a 1,1,1,3,3,3-hexafluoropropane product of greater than about 99.9 weight percent purity containing less than about 100 parts per million unsaturated fluorocarbons.
    Type: Grant
    Filed: March 3, 1998
    Date of Patent: January 5, 1999
    Assignee: AlliedSignal Inc.
    Inventors: Daniel Christopher Merkel, Addison Miles Smith, Kim Marie Fleming
  • Patent number: 5853550
    Abstract: Disclosed is a process for the separation of tar and non-volatile reagents from a reaction mixture formed when chlorinated carbon compounds are allowed to react with anhydrous hydrogen fluoride in a liquid phase to form fluorinated carbon compounds. The disclosed process leaves tar essentially free of HF and in a form allowing for safe, easy, and economical transfer and disposal.
    Type: Grant
    Filed: April 12, 1996
    Date of Patent: December 29, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Robert Brent Landers, Vijay Kumar Gupta, Vinci Martinez Felix
  • Patent number: 5852223
    Abstract: The purification of pentafluoroethane (HFC-125) which is composed of a process A, in which an unpurified mixture (1), containing at least chloropentafluoroethane (CFC-115) and pentafluoroethane (HFC-125) is reacted with hydrogen (4) in the presence of a catalyst in gas phase to reduce the said chloropentafluoroethane (CFC-115); and a process B, in which a reaction mixture produced by the preceding reaction is separated into a first mixture (3) composed mainly of hydrogen and a second mixture (2), composed mainly of pentafluoroethane (HFC-125). In this method, purification is performed by adding the said first mixture (3) to the said unpurified mixture (1) in a state that the hydrogen chloride is removed from the first mixture (3) in process B until the level of hydrogen chloride drops to 0.
    Type: Grant
    Filed: January 28, 1997
    Date of Patent: December 22, 1998
    Assignee: Daikin Industries, Ltd.
    Inventors: Satoru Kohno, Takashi Shibanuma
  • Patent number: 5849160
    Abstract: Pentafluoroethane (HFC-125) is more effectively and more simply separated from a reaction mixture in a process of producing HFC-125.A gas mixture containing perchloroethylene (PCE), HFC-125, hydrogen chloride (HCl) and hydrogen fluoride (HF) is passed through the first condensation stage to obtain the first vapor phase, which is passed through the second condensation stage to obtain the second vapor phase mainly containing HFC-125 and HCl and the second liquid phase, which is passed to a distillation stage to obtain a top fraction mainly containing HFC-125 and HCl and a bottom fraction containing the rest of the second liquid phase which bottom fraction is substantially free from HFC-125 and HCl, and HCl is separated out of the second vapor phase portion and the top fraction to obtain HFC-125, a concentration of PCE in the second liquid phase being such that it does not separate into immiscible liquid phases.
    Type: Grant
    Filed: July 2, 1997
    Date of Patent: December 15, 1998
    Assignee: Daikin Industries, Ltd.
    Inventors: Yukio Homoto, Takashi Shibanuma, Masanobu Nishitsuji
  • Patent number: 5846388
    Abstract: There is provided an azeotropic mixture of hydrogen fluoride (HF) and 1,1-difluoroethane (HFC152a). In addition, there is provided a process for the production of HFC152a having a step of more effectively recovering HF which does not contain HFC152a or HFC152a which does not contain HF in which step an azeotropic mixture is distilled off from a column top by subjecting a mixture containing HFC152a and HF, so that HF which does not contain HFC152a or HFC152a which does not contain HF is recovered from a column bottom.
    Type: Grant
    Filed: September 29, 1995
    Date of Patent: December 8, 1998
    Assignee: Daiken Industries Ltd.
    Inventors: Takehide Tsuda, Satoshi Komatsu
  • Patent number: 5830325
    Abstract: The disclosure relates to separating 1,1,1-trifluoroethane (HFC-143a 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: Grant
    Filed: March 28, 1996
    Date of Patent: November 3, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Barry Asher Mahler, Ralph Newton Miller
  • Patent number: 5800682
    Abstract: A liquid and vapor phase processes for the production of difluoromethane in which the risk of exposure to, and equipment fouling from, chlorofluoromethane is reduced. This reduction is accomplished from removing a sidestream containing monochloromonofluoromethane from a fluorination process distillation column.
    Type: Grant
    Filed: October 8, 1996
    Date of Patent: September 1, 1998
    Assignee: AlliedSignal Inc.
    Inventors: Gustavo Cerri, Kin Ching Kong
  • Patent number: 5789632
    Abstract: A mixture containing hydrogen fluoride and 1,1,1,3,3-pentafluoro-2,3-dichloropropane is subjected to distillation to form an azeotropic composition of 85 to 95 mol % of hydrogen fluoride and 15 to 5 mol % of 1,1,1,3,3-pentafluoro-2,3-dichloropropane, and the azeotropic composition is liquid-separated to form a lower liquid phase. Then, an azeotropic composition is withdrawn from the lower liquid phase by distillation, whereby 1,1,1,3,3-pentafluoro-2,3-dichloropropane is obtained.Without formation of an aqueous solution of diluted hydrofluoric acid, 1,1,1,3,3-pentafluoro-2,3-dichloropropane is obtained which is substantially free of hydrogen fluoride.
    Type: Grant
    Filed: June 20, 1996
    Date of Patent: August 4, 1998
    Assignee: Daikin Industries, Ltd.
    Inventors: Tatsuo Nakada, Hirokazu Aoyama
  • Patent number: 5789633
    Abstract: The instant invention relates to azeotropic or azeotrope-like compositions of hydrofluoric acid with at least one of 1,1-dichloroethane, 1-chloro-1-fluoroethane and 1,1-difluoroethane. The invention also relates to manufacturing processes for separating hydrofluoric acid from a mixture comprising hydrofluoric acid and one or more of the 1,1-dihaloethane.
    Type: Grant
    Filed: March 18, 1996
    Date of Patent: August 4, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Maria U. D. Beug-Deeb, Barry Asher Mahler, Ralph Newton Miller
  • Patent number: 5785822
    Abstract: The present invention provides a method for separating dichlorodifluoromethane from difluoromethane. More specifically, a process is provided for separating dichlorodifluoromethane and difluoromethane using azeotropic distillation.
    Type: Grant
    Filed: May 23, 1996
    Date of Patent: July 28, 1998
    Assignee: AlliedSignal Inc.
    Inventors: Gustavo Cerri, Kin Ching Kong, Charles Francis Swain, Rajat Subhra Basu
  • Patent number: 5779863
    Abstract: Provided is a novel method and system for separating and purifying perfluorocompounds (PFCs). The method comprises the steps of: (a) introducing a perfluorocompound-containing gas stream into a first distillation column; (b) removing a light product from the first column, and removing a heavy product from the first column; (c) introducing the first column light product into a second distillation column; (d) removing a light product from the second column, and removing a heavy product from the second column; (e) introducing the second column light product into a third distillation column; and (f) removing a light product from the third column, and removing a heavy product from the third column. The method and system can be advantageously used in the treatment of exhaust gases from semiconductor processing tools, and results in highly purified PFCs which can be recycled, thereby avoiding the release of PFCs into the atmosphere.
    Type: Grant
    Filed: January 16, 1997
    Date of Patent: July 14, 1998
    Assignees: Air Liquide America Corporation, Air Liquide Process and Construction
    Inventors: Bao Ha, Timothy Arcuri
  • Patent number: 5772852
    Abstract: A process for separating HCl from pentafluoroethane, chloropentafluoroethane, chlorotrifluoroethane, trifluoromethane, and other fully saturated and unsaturated fluorocarbons, chlorofluorocarbons and chlorocarbons.
    Type: Grant
    Filed: July 6, 1995
    Date of Patent: June 30, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Barry Asher Mahler, Vinci Martinez Felix, Ralph Newton Miller
  • Patent number: 5718807
    Abstract: The disclosure relates to removing impurities from hexafluoroethane (CF.sub.3 CF.sub.3), also known as PerFluoroCarbon 116 (PFC-116) or FluoroCarbon 116 (FC-116), by using azeotropic distillation such that an overhead product containing an 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: September 20, 1994
    Date of Patent: February 17, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Ralph Newton Miller, Mark Richard Deschere, Barry Asher Mahler, Olagappan Muthu
  • Patent number: 5707497
    Abstract: A process for the separation of hydrogen fluoride (HF) and of difluoromethane (F32) by fractional distillation and/or condensation, in at least one stage, including in at least one stage obtaining a stream whose HF and F32 contents correspond.
    Type: Grant
    Filed: February 27, 1995
    Date of Patent: January 13, 1998
    Assignee: Elf Atochem S.A.
    Inventors: Jean-Michel Galland, Dominique Rouzies
  • Patent number: 5696309
    Abstract: Disclosed is a method of chlorinating vinylidene chloride contained in a solution 1,1 -dichloro-1-fluoroethane to provide a chlorinated compound having a boiling point different from the 1,1-dichloro-1-fluoroethane to permit separation therefrom. The method comprises providing a solution containing 1,1-dichloro-1-fluoroethane and vinylidene chloride; introducing chlorine to the solution; and contacting the chlorine containing solution with a metal oxide to effect chlorination of the vinylidene chloride to produce one of 1,1,1,2-tetrachloroethane, trichloroethylene and pentachloroethane.
    Type: Grant
    Filed: April 17, 1995
    Date of Patent: December 9, 1997
    Assignee: LaRoche Industries, Inc.
    Inventors: Andrew Jackson, C. Bradford Boyce
  • Patent number: 5696310
    Abstract: A process for producing a substantially pure polyfluorinated aliphatic hydrocarbon from a crude reaction solution thereof containing unsaturated hydrocarbon and halogenated saturated and unsaturated aliphatic hydrocarbon impurities is disclosed. The process comprises, as a first step, treating said crude reaction solution with a dehydrohalogenation agent that does not substantially react with the polyfluorinated aliphatic hydrocarbon. The treatment converts the halogenated aliphatic impurities into olefinic impurities.As a second step to the process of this invention, the solution formed from the first step is further treated with an agent that transforms the olefinic hydrocarbon impurities into compounds that have a boiling point than the desired polyfluorinated aliphatic hydrocarbon. The transformed impurities are then separated from the polyfluorinated aliphatic hydrocarbon.
    Type: Grant
    Filed: April 12, 1996
    Date of Patent: December 9, 1997
    Inventors: Andrew Jackson, Randolph Kenneth Belter
  • Patent number: 5683554
    Abstract: Separation of 1,1-dichloro-1-fluoroethane (141b) from lower boiling components contained in a crude 141b feed stream mixture by adding the feed stream mixture, and, based upon the weight of 141b in the feed stream mixture, between 100 and 300 ppm of a component that will inhibit formation of 1,1-difluoro-1-chloroethane into a feed line of a distillation column operated at between 3 and 165 psig pressure with a temperature between 100.degree. F. and 250.degree. F. in the bottom reboiler section of the column.
    Type: Grant
    Filed: August 1, 1995
    Date of Patent: November 4, 1997
    Assignee: Elf Atochem North America, Inc.
    Inventors: Wayne E. Brooks, Craig Jolley
  • Patent number: 5656137
    Abstract: Inhibition of the formation of unsaturated carbon compounds during the heating of 141b by the use of a vessel pre-treated with HF to form an iron fluoride coating on the internal surfaces of said vessel.
    Type: Grant
    Filed: August 25, 1994
    Date of Patent: August 12, 1997
    Assignee: Elf Atochem North America, Inc.
    Inventors: Wayne E. Brooks, Craig Jolley
  • Patent number: 5626725
    Abstract: The invention relates to a process for separating 1,1-difluoroethane from its mixtures with hydrogen fluoride, in which the mixture is subjected to a distillation in a column operating at a pressure of less than 10 bar.
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: May 6, 1997
    Assignee: Solvay (Societe Anonyme)
    Inventors: Dominique Balthasart, Philippe Decap
  • Patent number: 5569798
    Abstract: A method of chlorinating vinylidene chloride contained in a solution 1,1-dichloro-1-fluoroethane to provide a chlorinated compound having a boiling point different from the 1,1-dichloro-1-fluoroethane to permit separation therefrom, the method comprising providing a solution containing 1,1-dichloro-1-fluoroethane and vinylidene chloride; and contacting said solution with chlorine and an alumina catalyst to effect chlorination of said vinylidene chloride to produce a chlorinated compound having a boiling point different than said 1,1 dichloro-1-fluoroethane.
    Type: Grant
    Filed: April 17, 1995
    Date of Patent: October 29, 1996
    Assignee: LaRoche Industries, Inc.
    Inventor: Andrew Jackson
  • Patent number: 5567281
    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: June 6, 1995
    Date of Patent: October 22, 1996
    Assignee: Elf Atochem North America, Incorporated
    Inventors: Richard M. Crooker, Maher Y. Elsheikh, Anthony D. Kelton, Morris P. Walker, Danny W. Wright
  • Patent number: 5563306
    Abstract: Described is a method for the purification of perfluorocarbons, or mixtures of perfluorocarbons, having impurities containing hydrogen and/or carbon-carbon double bonds. The impure perfluorocarbons or perfluorocarbon mixtures are reacted with strong aqueous bases in the presence of Ca.sup.2+ or Ba.sup.2+ ions and alcoholate ions together with secondary amines.
    Type: Grant
    Filed: November 3, 1994
    Date of Patent: October 8, 1996
    Assignee: Pharmpur GmbH
    Inventor: Hasso Meinert
  • Patent number: 5545778
    Abstract: A process for the preparation of one or more of CHClFCF.sub.3 (HCFC-124), CHF.sub.2 CClF.sub.2 (HCFC-124a) and CHF.sub.2 CF.sub.3 (HFC-125) by reaction of perchloroethylene with hydrogen fluoride in a single stage reaction vessel in the presence of a fluorination catalyst. These compounds are useful in a variety of industrial applications including blowing agents, refrigerants, sterilant gases and solvent applications. Distilling the reaction product produces a distillate comprising HCl, CHClFCF.sub.3, CHF.sub.2 CClF.sub.2 and CHF.sub.2 CF.sub.3 and a minor amount of HF which distillate is scrubbed to remove the acids. The bottoms product comprises perchloroethylene, hydrogen fluoride and organic by-products which is phase separated to sequester the hydrogen fluoride from the mixture of perchloroethylene and organic by-products. The hydrogen fluoride and mixture of perchloroethylene with organic by-products are then preferably re-mixed at a controlled rate and recycled to the reaction vessel.
    Type: Grant
    Filed: May 25, 1994
    Date of Patent: August 13, 1996
    Assignee: AlliedSignal Inc.
    Inventors: Hsueh S. Tung, Addison M. Smith, Charles F. Swain
  • Patent number: 5540818
    Abstract: A process for producing methanesulfonyl fluoride involves reacting methanesulfonyl chloride, a metal fluoride and water to obtain a reaction product, subjecting the reaction product to distillation in the presence of water in an amount of 0.7 times or more the amount of the methanesulfonyl chloride to obtain a distillate. The distillate has a water layer and a methanesulfonyl fluoride layer. The distillate is subjected to phase separation to separate the methanesulfonyl fluoride layer from the water layer, and the methanesulfonyl fluoride is recovered.
    Type: Grant
    Filed: March 29, 1995
    Date of Patent: July 30, 1996
    Assignee: Central Glass Co., Ltd.
    Inventors: Kenji Fujii, Tamio Nakamura, Yoshiyuki Kobayashi
  • Patent number: 5531867
    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: September 10, 1993
    Date of Patent: July 2, 1996
    Assignee: Elf Atochem North America, Inc.
    Inventors: Richard M. Crooker, Maher Y. Elsheikh, Anthony D. Kelton, Morris P. Walker, Danny W. Wright
  • Patent number: 5514251
    Abstract: The invention relates to binary azeotropic compositions between water and 1,1-dichloro-1-fluoroethane, 1-chloro-1,1-difluoroethane, 1,1,1-trifluoroethane, 1,1,1,2-tetrafluoroethane, 1,1-difluoroethane or trifluoroethylene, to a process for the removal of water from solutions by azeotropic distillation using these compositions, as well as to a process for the production of a hydrofluoroalkane in which water is removed from the mixture of reaction products by azeotropic distillation using these compositions.
    Type: Grant
    Filed: March 22, 1994
    Date of Patent: May 7, 1996
    Assignee: Solvay (Societe Anonyme)
    Inventors: Dominique Balthasart, Andre Jacquemart
  • Patent number: 5475169
    Abstract: Process for the removal of olefinic impurities from 1,1,1,2,3,3,3-heptafluoropropaneThe invention relates to a process for the removal of olefinic impurities from 1,1,1,2,3,3,3-heptafluoropropane (R 227) in which the contaminated R 227 is brought into contact with an alcohol and a base, and the R 227 is simultaneously or subsequently removed by distillation.
    Type: Grant
    Filed: May 7, 1992
    Date of Patent: December 12, 1995
    Assignee: Hoechst AG
    Inventors: Peter Hopp, Rolf-Michael Jansen
  • Patent number: 5470442
    Abstract: 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: Grant
    Filed: March 11, 1994
    Date of Patent: November 28, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Barry A. Mahler, Ralph N. Miller
  • Patent number: 5461177
    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: February 2, 1994
    Date of Patent: October 24, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Leo E. Manzer, V. N. M. Rao
  • Patent number: 5429720
    Abstract: A distillation process for separating spent organic solvents such as trichloroethane or d-limonene from their contaminants such as oil is improved by the addition of a perfluorinated alkane or mixture of such alkanes to permit more efficient separation of the solvents from the oil.
    Type: Grant
    Filed: January 26, 1994
    Date of Patent: July 4, 1995
    Assignee: The Dow Chemical Company
    Inventors: James A. Mertens, Felipe A. Donate
  • Patent number: 5430206
    Abstract: A method of recovering pure dichloropentafluoropropane from a mixture of dichloropentaflouropropane and chloroform (including breaking the azeotropic mixture thereof) involving selectively fluorinating the chloroform to the lower boiling dichloromonofluoromethane and then distilling to separate and recover pure dichloropentafluoropropane.
    Type: Grant
    Filed: October 25, 1991
    Date of Patent: July 4, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Abid N. Merchant, Allen C. Sievert
  • Patent number: 5426254
    Abstract: The invention relates to the separation of hydrogen fluoride (HF) from its mixtures with 1,1,1-trifluoro-2-chloroethane (F133a).By settling of the mixture of HF and F133a in the presence of trichloroethylene at a temperature below 0.degree. C., a lower organic phase which is poor in HF and an upper phase which is rich in HF are obtained. The latter can be directly recycled to the fluorination reactor or subjected to a distillation in order to separate, at the head, the HF/F133a azeotrope which is returned to the settler, and to recover, at the foot, practically pure HF. By distillation of the lower phase, the HF/F133a azeotrope which is returned to the settler is separated at the head and a mixture of F133a and trichloroethylene is recovered at the foot. The latter mixture is subjected to a distillation which makes it possible to separate, at the head, pure F133a from trichloroethylene at the foot.
    Type: Grant
    Filed: September 10, 1993
    Date of Patent: June 20, 1995
    Assignee: d'Elf Atochem S.A.
    Inventors: Jean-Michel Galland, Rene Perdriau, Dominique Rouzies
  • Patent number: 5426251
    Abstract: A process for preparing 1,1,1-trifluoro-2-chloroethane and/or 1,1,1,2-tetrafluoroethane, comprising the steps of reacting trichloroethylene and/or 1,1,1-trifluoro-2-chloroethane with hydrogen fluoride in the presence of a fluorinating catalyst in a gas pase, separating 1,1,1-trifluoro-2-chloroethane, hydrogen fluoride, and optionally trichloroethylene, from the reaction mixture obtained by the above reaction which contains 1,1,1-trifluoro-2-chloroethane, 1,1,1,2-tetrafluoroethane, hydrogen fluoride, and optionally trichloroethylene, and recycling them to the reaction step above, characterized in that at least a part of the reaction mixture is distilled in a distillation tower, 1,1,1,2-tetrafluoroethane-rich components are discharged from the top of the tower, and a mixture of 1,1,1-trifluoro-2-chloroethane and hydrogen fluoride, and optionally trichloroethylene, is discharged in the form of gas from the middle part of the tower at a temperature which is above the boiling point of the azeotropic mixture of 1,1
    Type: Grant
    Filed: July 21, 1993
    Date of Patent: June 20, 1995
    Assignee: Daikin Industries, Ltd.
    Inventors: Satoshi Komatsu, Satoshi Koyama, Yoshinori Tanaka, Takehide Tsuda
  • Patent number: 5421964
    Abstract: 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: Grant
    Filed: April 30, 1993
    Date of Patent: June 6, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Barry A. Mahler, Vinci M. Felix, Ralph N. Miller
  • Patent number: 5414167
    Abstract: The 1,1,2-trifluoro-1,2-dichloroethane content is reduced or removed from 1,1,1-trifluoro-2,2-dichloroethane by contacting a gaseous mixture comprising said compounds with chrome oxide (Cr.sub.2 O.sub.3) either as such or supported, at temperatures from 180.degree. to 400.degree. C.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: May 9, 1995
    Assignee: Ausimont S.p.A.
    Inventors: Letanzio Bragante, Paolo Cuzzato, Antonio Masiero
  • Patent number: 5401430
    Abstract: Hydrogen fluoride and 1,1,1-trifluoro-2-chloroethane forms an azeotropic mixture of which molar ratio of HF/1,1,1-trifluoro-2-chloroethane varies, for example, from about 60/40 at a pressure of 1.5 Kg/cm.sup.2 G and a temperature of 20.degree. C. to about 45/55 at a pressure of 15 Kg/cm.sup.2 G and a temperature of 87.degree.C.
    Type: Grant
    Filed: October 18, 1993
    Date of Patent: March 28, 1995
    Assignee: Daikin Industries, Ltd.
    Inventors: Takehide Tsuda, Nobuyoshi Iwashita, Satoshi Komatsu, Satoshi Koyama
  • Patent number: 5399796
    Abstract: This invention relates to a process for the purification of 1,1-dichloro-1-fluorethane.To remove unsaturated impurities such as 1,1-dichloroethylene and dichloracetylene the crude 1,1-dichloro-1-fluoroethane is subjected to the action of chlorine and/or of a hydracid. This treatment is carried out in the presence of a Lewis acid, or, only in the case of chlorine, by photochemical catalysis.
    Type: Grant
    Filed: November 29, 1993
    Date of Patent: March 21, 1995
    Assignee: Societe Atochem
    Inventors: Yves Correia, Michel Bergougnan, Jean Lesparre, Sylvain Perdrieux