Including Distillation Patents (Class 570/178)
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Patent number: 6120652Abstract: 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: GrantFiled: March 10, 1998Date of Patent: September 19, 2000Assignee: Central Glass CompanyInventors: Yasuo Hibino, Ryouichi Tamai
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Patent number: 6107267Abstract: 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: GrantFiled: August 20, 1998Date of Patent: August 22, 2000Assignee: E. I. du Pont de Nemours and CompanyInventors: V. N. Mallikarjuna Rao, Allen Capron Sievert, Munirpallam A. Subramanian
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Patent number: 6099694Abstract: 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: GrantFiled: March 23, 1998Date of Patent: August 8, 2000Assignee: AlliedSignal Inc.Inventors: Hang Thanh Pham, Rajiv R. Singh, Addison M. Smith, David P. Wilson, Raymond Hilton Percival Thomas, Gustavo Cerri
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Patent number: 6060629Abstract: 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: GrantFiled: September 10, 1999Date of Patent: May 9, 2000Assignee: AlliedSignal Inc.Inventors: Hang Thanh Pham, Rajiv Ratna Singh, Ian Robert Shankland, Hsueh Sung Tung
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Patent number: 6059933Abstract: 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: April 25, 1995Date of Patent: May 9, 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: 6047560Abstract: 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: GrantFiled: March 12, 1998Date of Patent: April 11, 2000Assignee: Showa Denko K.K.Inventors: Atsuo Nishimura, Toshio Nagayasu, Reiji Takahashi
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Patent number: 6039845Abstract: 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: GrantFiled: January 2, 1998Date of Patent: March 21, 2000Assignee: Elf Atochem S.A.Inventors: Rene Bertocchio, Eric Lacroix, Sylvain Perdrieux
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Patent number: 5948381Abstract: 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: GrantFiled: July 3, 1996Date of Patent: September 7, 1999Assignee: AlliedSignal Inc.Inventors: Richard Elmer Eibeck, Hang Thanh Pham, Valentine Theodore Zuba
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Patent number: 5928479Abstract: 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: GrantFiled: September 19, 1996Date of Patent: July 27, 1999Assignee: Imperial Chemical Industries PLCInventors: Paul Nicholas Ewing, Stuart Corr, John Stuart Martin, Michael John Watson
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Patent number: 5922175Abstract: 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: GrantFiled: January 30, 1998Date of Patent: July 13, 1999Assignee: ELF Atochem S.A.Inventors: Rene Bertocchio, Eric Deslandes, Eric Lacroix
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Patent number: 5919340Abstract: 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: GrantFiled: February 14, 1997Date of Patent: July 6, 1999Assignee: Daikin Industries Ltd.Inventors: Satoru Kohno, Takashi Shibanuma
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Patent number: 5874657Abstract: 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: GrantFiled: October 29, 1997Date of Patent: February 23, 1999Assignee: E. I. du Pont de Nemours and CompanyInventors: Ralph Newton Miller, Barry Asher Mahler
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Patent number: 5866730Abstract: 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: GrantFiled: April 2, 1993Date of Patent: February 2, 1999Assignee: E. I. du Pont de Nemours and CompanyInventor: V. N. Mallikarjuna Rao
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Patent number: 5856595Abstract: 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: GrantFiled: March 3, 1998Date of Patent: January 5, 1999Assignee: AlliedSignal Inc.Inventors: Daniel Christopher Merkel, Addison Miles Smith, Kim Marie Fleming
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Patent number: 5853550Abstract: 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: GrantFiled: April 12, 1996Date of Patent: December 29, 1998Assignee: E. I. du Pont de Nemours and CompanyInventors: Robert Brent Landers, Vijay Kumar Gupta, Vinci Martinez Felix
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Patent number: 5852223Abstract: 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: GrantFiled: January 28, 1997Date of Patent: December 22, 1998Assignee: Daikin Industries, Ltd.Inventors: Satoru Kohno, Takashi Shibanuma
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Patent number: 5849160Abstract: 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: GrantFiled: July 2, 1997Date of Patent: December 15, 1998Assignee: Daikin Industries, Ltd.Inventors: Yukio Homoto, Takashi Shibanuma, Masanobu Nishitsuji
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Patent number: 5846388Abstract: 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: GrantFiled: September 29, 1995Date of Patent: December 8, 1998Assignee: Daiken Industries Ltd.Inventors: Takehide Tsuda, Satoshi Komatsu
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Patent number: 5830325Abstract: 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: GrantFiled: March 28, 1996Date of Patent: November 3, 1998Assignee: E. I. du Pont de Nemours and CompanyInventors: Barry Asher Mahler, Ralph Newton Miller
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Patent number: 5800682Abstract: 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: GrantFiled: October 8, 1996Date of Patent: September 1, 1998Assignee: AlliedSignal Inc.Inventors: Gustavo Cerri, Kin Ching Kong
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Patent number: 5789632Abstract: 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: GrantFiled: June 20, 1996Date of Patent: August 4, 1998Assignee: Daikin Industries, Ltd.Inventors: Tatsuo Nakada, Hirokazu Aoyama
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Patent number: 5789633Abstract: 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: GrantFiled: March 18, 1996Date of Patent: August 4, 1998Assignee: E. I. du Pont de Nemours and CompanyInventors: Maria U. D. Beug-Deeb, Barry Asher Mahler, Ralph Newton Miller
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Patent number: 5785822Abstract: 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: GrantFiled: May 23, 1996Date of Patent: July 28, 1998Assignee: AlliedSignal Inc.Inventors: Gustavo Cerri, Kin Ching Kong, Charles Francis Swain, Rajat Subhra Basu
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Patent number: 5779863Abstract: 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: GrantFiled: January 16, 1997Date of Patent: July 14, 1998Assignees: Air Liquide America Corporation, Air Liquide Process and ConstructionInventors: Bao Ha, Timothy Arcuri
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Patent number: 5772852Abstract: A process for separating HCl from pentafluoroethane, chloropentafluoroethane, chlorotrifluoroethane, trifluoromethane, and other fully saturated and unsaturated fluorocarbons, chlorofluorocarbons and chlorocarbons.Type: GrantFiled: July 6, 1995Date of Patent: June 30, 1998Assignee: E. I. du Pont de Nemours and CompanyInventors: Barry Asher Mahler, Vinci Martinez Felix, Ralph Newton Miller
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Patent number: 5718807Abstract: 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: GrantFiled: September 20, 1994Date of Patent: February 17, 1998Assignee: 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: 5707497Abstract: 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: GrantFiled: February 27, 1995Date of Patent: January 13, 1998Assignee: Elf Atochem S.A.Inventors: Jean-Michel Galland, Dominique Rouzies
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Patent number: 5696309Abstract: 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: GrantFiled: April 17, 1995Date of Patent: December 9, 1997Assignee: LaRoche Industries, Inc.Inventors: Andrew Jackson, C. Bradford Boyce
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Patent number: 5696310Abstract: 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: GrantFiled: April 12, 1996Date of Patent: December 9, 1997Inventors: Andrew Jackson, Randolph Kenneth Belter
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Patent number: 5683554Abstract: 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: GrantFiled: August 1, 1995Date of Patent: November 4, 1997Assignee: Elf Atochem North America, Inc.Inventors: Wayne E. Brooks, Craig Jolley
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Patent number: 5656137Abstract: 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: GrantFiled: August 25, 1994Date of Patent: August 12, 1997Assignee: Elf Atochem North America, Inc.Inventors: Wayne E. Brooks, Craig Jolley
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Patent number: 5626725Abstract: 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: GrantFiled: April 10, 1995Date of Patent: May 6, 1997Assignee: Solvay (Societe Anonyme)Inventors: Dominique Balthasart, Philippe Decap
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Patent number: 5569798Abstract: 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: GrantFiled: April 17, 1995Date of Patent: October 29, 1996Assignee: LaRoche Industries, Inc.Inventor: Andrew Jackson
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Patent number: 5567281Abstract: 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: June 6, 1995Date of Patent: October 22, 1996Assignee: Elf Atochem North America, IncorporatedInventors: Richard M. Crooker, Maher Y. Elsheikh, Anthony D. Kelton, Morris P. Walker, Danny W. Wright
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Patent number: 5563306Abstract: 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: GrantFiled: November 3, 1994Date of Patent: October 8, 1996Assignee: Pharmpur GmbHInventor: Hasso Meinert
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Patent number: 5545778Abstract: 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: GrantFiled: May 25, 1994Date of Patent: August 13, 1996Assignee: AlliedSignal Inc.Inventors: Hsueh S. Tung, Addison M. Smith, Charles F. Swain
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Patent number: 5540818Abstract: 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: GrantFiled: March 29, 1995Date of Patent: July 30, 1996Assignee: Central Glass Co., Ltd.Inventors: Kenji Fujii, Tamio Nakamura, Yoshiyuki Kobayashi
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Patent number: 5531867Abstract: 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: September 10, 1993Date of Patent: July 2, 1996Assignee: 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: 5514251Abstract: 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: GrantFiled: March 22, 1994Date of Patent: May 7, 1996Assignee: Solvay (Societe Anonyme)Inventors: Dominique Balthasart, Andre Jacquemart
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Patent number: 5475169Abstract: 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: GrantFiled: May 7, 1992Date of Patent: December 12, 1995Assignee: Hoechst AGInventors: Peter Hopp, Rolf-Michael Jansen
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Patent number: 5470442Abstract: The disclosure relates to separating 1,1,2,2 tetrafluoroethane (HFC-134) and 1,1,1,2 tetrafluoroethane (HFC-134a) from each other and/or from fluorocarbon impurities by using extractive distillation with an extractive agent comprising an alcohol. Examples of suitable extractive agents comprise at least one member from the group of methanol, butanol, ethanol, propanol, their isomers and cyclic compounds thereof, among others.Type: GrantFiled: March 11, 1994Date of Patent: November 28, 1995Assignee: E. I. Du Pont de Nemours and CompanyInventors: Barry A. Mahler, Ralph N. Miller
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Patent number: 5461177Abstract: 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: February 2, 1994Date of Patent: October 24, 1995Assignee: E. I. Du Pont de Nemours and CompanyInventors: Leo E. Manzer, V. N. M. Rao
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Patent number: 5429720Abstract: 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: GrantFiled: January 26, 1994Date of Patent: July 4, 1995Assignee: The Dow Chemical CompanyInventors: James A. Mertens, Felipe A. Donate
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Patent number: 5430206Abstract: 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: GrantFiled: October 25, 1991Date of Patent: July 4, 1995Assignee: E. I. Du Pont de Nemours and CompanyInventors: Abid N. Merchant, Allen C. Sievert
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Patent number: 5426254Abstract: 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: GrantFiled: September 10, 1993Date of Patent: June 20, 1995Assignee: d'Elf Atochem S.A.Inventors: Jean-Michel Galland, Rene Perdriau, Dominique Rouzies
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Patent number: 5426251Abstract: 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 1,1Type: GrantFiled: July 21, 1993Date of Patent: June 20, 1995Assignee: Daikin Industries, Ltd.Inventors: Satoshi Komatsu, Satoshi Koyama, Yoshinori Tanaka, Takehide Tsuda
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Patent number: 5421964Abstract: The present invention discloses an extractive distillation process for separating HCl from pentafluoroethane, chloropentafluoroethane, chlorotrifluoroethane, trifluoromethane, and other fully saturated and unsaturated fluorocarbons, chlorofluorocarbons and chlorocarbons.Type: GrantFiled: April 30, 1993Date of Patent: June 6, 1995Assignee: E. I. Du Pont de Nemours and CompanyInventors: Barry A. Mahler, Vinci M. Felix, Ralph N. Miller
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Patent number: 5414167Abstract: 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: GrantFiled: April 28, 1994Date of Patent: May 9, 1995Assignee: Ausimont S.p.A.Inventors: Letanzio Bragante, Paolo Cuzzato, Antonio Masiero
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Patent number: 5401430Abstract: 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: GrantFiled: October 18, 1993Date of Patent: March 28, 1995Assignee: Daikin Industries, Ltd.Inventors: Takehide Tsuda, Nobuyoshi Iwashita, Satoshi Komatsu, Satoshi Koyama
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Patent number: 5399796Abstract: 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: GrantFiled: November 29, 1993Date of Patent: March 21, 1995Assignee: Societe AtochemInventors: Yves Correia, Michel Bergougnan, Jean Lesparre, Sylvain Perdrieux