Purification Or Recovery Patents (Class 570/177)
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Patent number: 6281396Abstract: A halocarbon product made from the reaction of excess hydrogen fluoride with a halocarbon, containing excess hydrogen fluoride as an azeotrope is purified by fluorination in the presence of additional halocarbon or halo-olefin.Type: GrantFiled: August 11, 1995Date of Patent: August 28, 2001Assignee: E. I. du Pont de Nemours and CompanyInventors: Leo Ernest Manzer, V. N. Mallikarjuna Rao
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Patent number: 6235161Abstract: Inhibition of the formation of unsaturated carbon compounds during the heating of 141b involving the addition of various inhibitors such as butylene oxide and/or the use of a vessel made of a nickel alloy.Type: GrantFiled: November 25, 1997Date of Patent: May 22, 2001Assignee: Atofina Chemicals, Inc.Inventors: Richard M. Crooker, Maher Y. Elsheikh, Anthony D. Kelton, Morris P. Walker, Danny W. Wright
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Patent number: 6180840Abstract: A production method in which reaction processes are divided into two regions comprising one reaction region where mainly perchloroethylene is made to react with HF in a vapor phase in the presence of a catalyst and the other reaction region where HCFC-123 (CF3CHCl2) and/or HCFC-124 (CF3CFHCl) is made to react with HF in a vapor phase in the presence of a catalyst, the former region being kept at a higher pressure and the latter region at a lower pressure during the reaction procedure. By this method it is possible to keep the conversion of perchloroethylene at a high level while securing the life of a catalyst, and it is also possible to raise the selectivity of HFC-125. This is a method of producing HFC-125 in which the content of CFC-115 is lowered to not more than 15 vol % of the total amount of HFC-125 and CFC-115, and then CFC-115 is made to react with hydrogen in the presence of a catalyst.Type: GrantFiled: June 30, 1998Date of Patent: January 30, 2001Assignee: Daiken Industries Ltd.Inventors: Takashi Shibanuma, Yukio Homoto, Satoshi Komatsu, Toshikazu Yoshimura
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Patent number: 6156944Abstract: A process for the separation of mixtures containing halocarbons and hydrogen fluoride. Either water alone or a blend comprising water and hydrogen fluoride is added to a mixture comprising a halocarbon and hydrogen fluoride to thereby form a first phase rich in the halocarbon and a second phase rich in hydrogen fluoride and water. The most preferred halocarbon is 1,1,1,3,3-pentafluoropropane. Preferably, the first and second phases are then separated. Optionally, the second phase rich in hydroger fluoride and water is also separated.Type: GrantFiled: March 3, 1998Date of Patent: December 5, 2000Assignee: Honeywell International Inc.Inventors: Hang T. Pham, Rajiv R. Singh, Charles F. Swain, Michael Van Der Puy
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Patent number: 6147268Abstract: A method for removing one or more fluorinated alkenes from a fluid comprises the step of contacting the fluid with an N-, S-, or P-containing nucleophile for a time sufficient to form an N-, S-, or P-containing nucleophile-fluoroalkene adduct. The nucleophile, and therefore the adduct, can be covalently bonded, coated or sorbed to a particulate support which can be enmeshed in a porous, fibrous web. In a preferred embodiment the fluorinated alkene can have the formula ##STR1## wherein A=F or R.sub.f ; X=H, F, Cl, R.sub.f, or YR.sub.f ; Z=H, F, Cl, or R.sub.f ; and Y=O, N, or S; with the proviso that at least one A=F, and at most one of Z and X is H; wherein each R.sub.f is independently selected from the group consisting of highly fluorinated or perfluorinated alkyl groups; and a combination of any two R.sub.f groups can be linked to form a cyclic structure. The R.sub.f alkyl chains may contain from 1-20 carbon atoms, with 1-12 carbon atoms preferred. The R.sub.Type: GrantFiled: September 16, 1998Date of Patent: November 14, 2000Assignee: 3M Innovative Properties CompanyInventors: Mark Eugene Mueller, Donald Frederick Hagen, Yuri Cheburkov, Fred Lynn DeRoos, Glenn Delmont Johnson, John Stephen Marhevka, Venkateswarlu Pothapragada
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Patent number: 6147267Abstract: A process is disclosed for recovering at least one perfluorocycloalkane selected from the group consisting of octafluorocyclobutane, hexafluoro-bis(trifluoromethyl)cyclobutane (1,2 and 1,3; cis and trans), and heptafluoro(trifluoromethyl)cyclobutane from a mixture comprising (a) the perfluorocycloalkane, (b) olefinic impurity and, optionally, (c) saturated chlorine-containing impurity selected from the group consisting of chlorocarbons, hydrochlorocarbons, hydrochlorofluorocarbons, chlorofluorocarbons and mixtures thereof.Type: GrantFiled: October 29, 1999Date of Patent: November 14, 2000Assignee: E. I. du Pont de Nemours and CompanyInventors: Allen Capron Sievert, V. N. Mallikarjuna Rao
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Patent number: 6143938Abstract: A process is disclosed for recovering at least one perhalocycloalkane selected from the group consisting of octafluorocyclobutane, hexafluoro-bis(trifluoromethyl)cyclobutane (1,2 and 1,3; cis and trans), 1,2-dichloro-1,2,3,3,4,4-hexafluorocyclobutane (cis and trans), 1,1,2,2-tetrachloro-3,3,4,4-tetrafluorocyclobutane, 1-chloro-1,2,2,3,3,4-hexafluoro-4-(trifluoromethyl)-cyclobutane, heptafluoro(trifluoromethyl)cyclobutane and chloroheptafluoro-cyclobutane from a mixture comprising (a) the perhalocycloalkane, (b) olefinic impurity and optionally (c) saturated fluorine-containing impurity selected from the group consisting of hydrochlorofluorocarbons, hydrofluorocarbons and mixtures thereof.Type: GrantFiled: October 29, 1999Date of Patent: November 7, 2000Assignee: E. I. du Pont de Nemours and CompanyInventors: Allen Capron Sievert, V. N. Mallikarjuna Rao
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Patent number: 6111151Abstract: Process for removing water from compositions containing water, organics and hydrogen fluoride (e.g. product stream from vapour phase hydrofluorination processes, e.g. manufacture of HFA 134a, HFA 125 or HFA 32) by phase separation and purge of the aqueous layer.Type: GrantFiled: February 8, 1999Date of Patent: August 29, 2000Assignee: Imperial Chemical Industries PLCInventors: Paul Nicholas Ewing, Paul David Bernard Bujac, David William Bonniface
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Patent number: 6101818Abstract: A method for separating water from a chemical mixture is provided. In the process of the invention, water is separated from a chemical mixture by contacting the chemical mixture with a water-soluble polymer.Type: GrantFiled: November 10, 1997Date of Patent: August 15, 2000Assignee: AlliedSignal Inc.Inventors: Raymond Hilton Percival Thomas, Rajiv Ratna Singh, Jeffrey Warren McKown, Roy Phillip Robinson, Stephen Alan Cottrell
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Patent number: 6103944Abstract: Water present in a hot gaseous product stream from a reactor system A.B (FIG. 1) containing hydrogen fluoride is separated from the stream in order to eliminate a potentially corrosive combination of water and HF. The water is removed by contacting the gaseous product stream with liquid HF in a distillation column so as to obtain a bottoms product containing liquid HF and water and a top product containing dry HF and the product to be recovered. The invention encompasses the separation process, a vessel for carrying out the process (FIGS. 2 to 4), a control system for the liquid HF supply to the distillation column (FIGS. 5 and 6) and a recovery system for recovering HF employed during operation of the reactor system in different regimes employing HF as a fluorination agent, as a diluent during catalyst regeneration and/or catalyst prefluorination (FIG. 7).Type: GrantFiled: May 2, 1994Date of Patent: August 15, 2000Assignee: Imperial Chemical Industries PLCInventors: Charles Brian Blake, James Malcolm Forsyth, Ann San Liow, Stephen John Adams, Ralph Jones Doy, Rowland John Porter Brierley, Jane Andrea Eileen Roberts, Brian Schofield, Neil David Shilling
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Patent number: 6077982Abstract: In the synthesis of 1,1,1,3,3-pentafluoropropane (R-245fa), a mixture of R-245fa and the impurity 1-chloro-3,3,3-trifluoropropene (R-1233zd) is purified and R-1233zd is removed from the mixture by contacting the mixture with 1-5 mols of chlorine for each mol of R-1233zd in the presence of ultraviolet light having a wavelength between about 300 to 400 nm which provides at least 0.02 watts-hour/kg of the mixture, the R-1233zd being reduced to below 10 wt. ppm or lower, as it is converted to 1,2,2-trichloro-3,3,3-trifluoropropane (R-233) or other propane which contains more chlorine and which has a higher boiling point than R-245fa and can be separated easily from R-245fa, the photochlorination being effected in a manner such that at least about 96 wt. % of the starting amount of R-245fa is maintained in the mixture.Type: GrantFiled: July 27, 1998Date of Patent: June 20, 2000Assignee: Allied Signal Inc.Inventors: Stephen Frederic Yates, Romulus Gaita
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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: 6013846Abstract: An azeotrope containing HF and 1233zd is provided, as are methods for separating this azeotrope from mixtures of HF and 1233zd which are HF-rich or 1233zd-rich and methods for making use of the azeotrope and separation methods to improve processes for preparing 1233zd, an intermediate used in the preparation of 245fa. 245fa is a known foam blowing agent and refrigerant.Type: GrantFiled: March 5, 1998Date of Patent: January 11, 2000Assignee: Elf Atochem North America, Inc.Inventors: John A. Wismer, Michael S. Bolmer, Bin Chen
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Patent number: 5990364Abstract: In order to purify a crude pentafluoroethane (F125) containing chloropentafluoroethane (F115), it is subjected to a heat treatment in the presence of hydrogen, the treatment being carried out at a temperature at least equal to 550.degree. C. and with an H.sub.2 /F115 molar ratio of at least 10.Type: GrantFiled: July 30, 1997Date of Patent: November 23, 1999Inventors: Jean-Pierre Schirmann, Serge Hub, Eric Lacroix, Andre Lantz
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Patent number: 5973215Abstract: A process is disclosed for the liquid phase separation and recovery of hydrogen fluoride from a mixture comprising hydrogen fluoride and a fluorinated organic hydrocarbon. The process requires that the mixture be treated with a sufficient amount of a coupled phase-separating agent comprising an organic or inorganic salt, an alkanolamine or mixtures thereof and a substituted or unsubstituted aromatic compound to form a first and a second phase. The first phase that is formed is a hydrogen fluoride-rich phase that additionally contains substantially all of said salt, said alkanolamine or mixtures thereof from the coupled phase-separating agent. The second phase comprises substantially all of said aromatic compound and the fluorinated organic hydrocarbon. It is substantially free of hydrogen fluoride. The phases are separated from each other.Type: GrantFiled: March 16, 1998Date of Patent: October 26, 1999Assignee: LaRoche Industries IncInventor: Randolph K. Belter
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Patent number: 5962753Abstract: Process for the manufacture of pentafluoroethane ?HFC 125! by reaction of perchloroethylene with hydrogen fluoride in the vapor phase over a fluorination catalyst in a fluorination reactor with recycle of dichlorotrifluoroethane ?HCFC 123! and chlorotetrafluoroethane ?HCFC 124! to the fluorination reactor, wherein tetrafluoroethane ?HFC 134a! is also recycled to the fluorination reactor. The tetrafluoroethane and the chlorotetrafluoroethane can both be separated from the product stream in a single distillation column and recycled, together to the fluorination reactor.Type: GrantFiled: February 18, 1997Date of Patent: October 5, 1999Assignee: Imperial Chemical Industries PLCInventors: Charles John Shields, Paul Nicholas Ewing
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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: 5919994Abstract: Processes for decreasing the chlorine to carbon ratio for halogenated hydrocarbons containing chlorine and from 1 to 6 carbon atoms, in the presence of a catalyst are disclosed. The processes are each characterized by employing a catalyst comprising ruthenium on a support of (i) fluorided alumina, (ii) aluminum fluoride, or (iii) fluorides of Zn, Mg, Ca, Ba, Y, Sm, Eu, and/or Dy. Also disclosed are multiphase catalyst compositions of ruthenium supported on fluorides of Zn, Mg, Ca, Ba, Y, Sm, Eu and/or Dy.Type: GrantFiled: July 28, 1997Date of Patent: July 6, 1999Assignee: E. I. du Pont de Nemours and CompanyInventor: Velliyur Nott Mallikarjuna Rao
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Patent number: 5914432Abstract: A halogenated compound (I) containing one or more >C.dbd.O, olefinic and/or aromatic >C.dbd.C< groups is hydrogenated for producing a halogenated compound (II) having no or a decreased level of >C.dbd.O, olefinic and/or aromatic >C.dbd.C< groups. In the hydrogenation process a liquid feed stream comprising one or more of these compounds (I) is contacted with a hydrogen-rich gaseous stream and a liquid recycle stream comprising one or more of these compounds (II) in the presence of a catalyst.Type: GrantFiled: March 27, 1997Date of Patent: June 22, 1999Assignee: The Dow Chemical CompanyInventor: Celio Lume-Pereira
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Patent number: 5895639Abstract: The invention provides a process for the separation of azeotropic mixtures of fluorocarbons from hydrogen fluoride. The most preferred fluorocarbon for this invention is 1,1,1,3,3-pentafluoropropane, which is also known as HFC-245fa. The separation in conducted by adding sulfuric acid to the mixture while the mixture is in either the liquid or gaseous states.Type: GrantFiled: July 3, 1996Date of Patent: April 20, 1999Assignee: AlliedSignal Inc.Inventors: Charles Francis Swain, Rajiv Ratna Singh, Hang Thanh Pham
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Patent number: 5874658Abstract: A method is disclosed for separating a mixture of at least one hydrofluorocarbon from hydrogen fluoride. The method comprising treating said mixture with a compound selected from the group consisting of an alkanolamine of formulaNH.sub.a (CH.sub.b R.sub.c).sub.dwhere R is C.sub.1 to C.sub.6 linear or branched alkylene substituted with at least one hydroxy group, wherein a and d are the integers 1 or 2 and a+d=3 and b is 0 or the integer 1 or 2 and b+c=3, C.sub.6 to C.sub.10 aryl unsubstituted or substituted with halo or halo-substituted C.sub.1 to C.sub.6, alkyl, sulfuric acid and sulfuric acid admixed with at least one alkali metal sulfate. The hydrofluorocabon and HF form two separate phases by this treatment. The phases are readily separated.Type: GrantFiled: September 12, 1997Date of Patent: February 23, 1999Assignee: LaRoche Industries Inc.Inventor: Randolph K. Belter
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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: 5847244Abstract: A production method in which reaction processes are divided into two regions comprising one reaction region where mainly perohloroethylene is made to react with HF in a vapor phase in the presence of a catalyst and the other reaction region where HCFC-123 (CF.sub.3 CHCl.sub.2) and/or HCFC-124 (CF.sub.3 CFHCl) is made to react with HF in a vapor phase in the presence of a catalyst, the former region being kept at a higher pressure and the latter region at a lower pressure during the reaction procedure. By this method it is possible to keep the conversion of perchloroethylene at a high level while securing the life of a catalyst, and it is also possible to raise the selectivity of HFC-125. This is a method of producing HFC-125 in which the content of CFC-115 is lowered to not more than 15 vol % of the total amount of HFC-125 and CFC-115, and then CFC-115 is made to react with hydrogen in the presence of a catalyst.Type: GrantFiled: February 13, 1998Date of Patent: December 8, 1998Assignee: Daikin Industries, Ltd.Inventors: Takashi Shibanuma, Yukio Homoto, Satoshi Komatsu, Toshikazu Yoshimura
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Patent number: 5801294Abstract: In order to remove olefinic impurities present in a hydrofluorocarbon such as pentafluoroethane (R-125), the impure hydrofluorocarbon is treated with oxygen in the absence of catalyst or of active charcoal.The process is well suited to the purification of fluoroethanes and, more particularly, to that of pentafluoroethane.Type: GrantFiled: June 5, 1997Date of Patent: September 1, 1998Assignee: Elf Atochem S.A.Inventors: Jean-Marc Sage, Eric Lacroix
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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: 5780695Abstract: A process for saturating an olefin-containing halogenated organic stream to produce saturated halogenated organic compounds while minimizing the hydrodehalogenation of the organic compounds.Type: GrantFiled: October 31, 1995Date of Patent: July 14, 1998Assignee: UOPInventor: Tom N. Kalnes
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Patent number: 5773671Abstract: The invention relates to a novel process for purifying HCFC-123 and HCFC-124 comprising:(a) reacting a fluorination reaction product comprising HCFC-123 and HCFC-123a and/or HCFC-124 and HCFC-124a wherein at least one of said HCFC-123a or HCFC-124a is present in an amount not less than 5 weight percent relative to HCFC-123 or HCFC-124 respectively in the product with anhydrous HF in the presence of a fluorination catalyst under conditions such that the amount of HCFC-123a and/or HCFC-124a relative to HCFC-123 and/or HCFC-124 respectively in the product is reduced to less than 5 weight percent.The pure product (i.e., HCFC-123 or HCFC-124) may be used in a variety of applications including solvent, refrigerant, sterilant gas and blowing agent applications.Type: GrantFiled: December 17, 1996Date of Patent: June 30, 1998Assignee: Allied SignalInventor: Hsueh Sung Tung
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Patent number: 5750808Abstract: A process is disclosed for the dehydrohalogenation of partially halogenated ethanes of the formula C.sub.2 H.sub.a Cl.sub.b F.sub.c where a is an integer from 1 to 4, b is an integer from 0 to 3 and c is an integer form 1 to 5 to produce olefins selected from the group consisting of C.sub.2 H.sub.a-1 Cl.sub.b-1 F.sub.c and C.sub.2 H.sub.a-1 Cl.sub.b F.sub.c-1. The process involves contacting C.sub.2 H.sub.a Cl.sub.b F.sub.c with a zeolite selected from the group consisting of NaX and CsY. Selective reaction of one isomer from a mixture of two isomers is disclosed as a means for purification of the relatively unreactive isomer. Also disclosed is a process for producing perfluorocyclobutane which involves contacting CHF.sub.2 CClF.sub.2 with such zeolites.Type: GrantFiled: July 9, 1996Date of Patent: May 12, 1998Assignee: E. I. du Pont de Nemours and CompanyInventors: Wendell Richard Cassel, David Richard Corbin, V.N. Mallikarjuna Rao
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Patent number: 5744661Abstract: A method for removing unsaturated impurities from 1,1-difluoroethane by intimately contacting the impure 1,1-difluoroethane with sulfuric acid. This process is especially useful for removing one or more unsaturated halocarbons having two carbon atoms such as vinyl chloride, vinyl fluoride and blends thereof from the 1,1-difluoroethane.Type: GrantFiled: October 7, 1996Date of Patent: April 28, 1998Assignee: AlliedSignal Inc.Inventors: Matthew Hermes Luly, Addison Miles Smith, Kane David Cook
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Patent number: 5744669Abstract: A process for the conversion of a halogenated organic stream containing trace quantities of organic nitrates to produce a stream comprising hydrogenated hydrocarbonaceous compounds free from organic nitrates and halogenated organic compounds by means of contacting the feed stream and hydrogen with a selective hydrogenation catalyst in a first hydrogenation zone at hydrogenation conditions to convert the organic nitrates into water-soluble nitrogen compounds while effectively minimizing the production of hydrogen halide compounds. The resulting effluent from the first hydrogenation zone is contacted with an aqueous scrubbing solution to recover at least a portion of the water-soluble nitrogen compounds in order to produce a stream containing halogenated organic compounds and essentially free of nitrogen compounds which is then introduced into a second hydrogenation zone operated at selected hydrogenation conditions to produce water-soluble hydrogen halide compounds and hydrogenated hydrocarbonaceous compounds.Type: GrantFiled: January 30, 1997Date of Patent: April 28, 1998Assignee: UOPInventors: Tom N. Kalnes, George R. Hibel, Chwu-Ching Jan
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Patent number: 5723702Abstract: There is a process for removing moisture from chlorodifluoromethane (CHClF.sub.2) containing moisture in excess in the preparation of chlorodifluoromethane comprising lowering the partial pressure of water in the chlorodifluoromethane gas by contacting the chlorodifluoromethane gas with an aqueous solution of calcium chloride of more than 5% by weight.Type: GrantFiled: March 13, 1996Date of Patent: March 3, 1998Assignee: Korea Institute of Science and TechnologyInventors: Young Soo Kwon, Kun You Park, Sang-Deuk Lee, Honggon Kim
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Patent number: 5705718Abstract: To remove the unsaturated impurities (in particular 1-chloro-2,2-difluoroethylene and polyfluoropropenes) present in crude 1,1,1,2-tetrafluoroethane (F134a), a gaseous mixture of crude F134a, of hydrofluoric acid and of chlorine is treated in gaseous phase in the presence of a fluorination catalyst at a temperature of between 100.degree. and 300.degree. C. and at a pressure between atmospheric pressure and 2.5 MPa, the molar ratio HF/F134a being between 0.05 and 0.5 and the molar ratio Cl.sub.2 /F134a between 0.0001 and 0.1.Type: GrantFiled: October 15, 1996Date of Patent: January 6, 1998Assignee: Elf Atochem S.A.Inventors: Bernard Cheminal, Andre Lantz
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Patent number: 5698750Abstract: Refrigerants, such as Freon.RTM. 12 and other potential ozone depleting substances will be in short supply as their production is phased out, and until existing refrigeration equipment is retrofitted to receive more environmentally friendly refrigerants. Existing supplies of such refrigerants when contaminated with other refrigerants especially hydrofluoroalkanes like Freon 22 can form azeotropes, which are not readily separated by conventional distillation methods, are selectively decomposed in-situ by reacting with aqueous solutions of metal hydroxides or other bases. The remaining non-reacted refrigerant-containing composition is readily recycled by separation and recovery methods from the reaction mixture to provide a reusable refrigerant composition virtually free of contaminating refrigerant.Type: GrantFiled: October 30, 1995Date of Patent: December 16, 1997Assignee: Commodore Laboratories, Inc.Inventors: Robert W. Mouk, Albert E. Abel
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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: 5684219Abstract: A process is disclosed for the preparation of a fluorinated aliphatic olefin having the formulaCH.sub.a F.sub.3-a --CH.sub.2 --CH.sub.b F.sub.3-bwherein a is 0 or the integer 1 or d and b is 0 or the integer 1, 2 or 3.In the first step of the process, a chlorinated olefinic hydrocarbon of the formulaCH.sub.c Cl.sub.2-c .dbd.CH--CH.sub.d Cl.sub.3-dwherein c is 0 or the integer 1 and d is 0 or the integer 1 or 2 is reacted with anhydrous hydrogen fluoride for a period of time and at a temperature sufficient to form a chlorofluoro olefin of the formulaCH.sub.e Cl.sub.2-e .dbd.CH--CH.sub.f F.sub.3-fwherein e is 0 or the integer 1 and f is 0 or the integer 1 or 2.The chlorofluoro olefin produced in the first step is then reacted with anhydrous hydrogen fluoride in a second reaction. This second reaction is catalyzed with at least one compound that is a metal oxide or metal halide. Mixtures of said metal oxides, metal halides and metal oxides with metal halides may also be used.Type: GrantFiled: November 5, 1996Date of Patent: November 4, 1997Assignee: LaRoche Industries Inc.Inventors: C. Bradford Boyce, Randolph Kenneth Belter
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Patent number: 5679876Abstract: The invention relates to the purification of pentafluoroethane (F125) containing chloropentafluoroethane (F115) by vapor-phase catalytic hydrogenolysis.A catalyst based on palladium deposited on aluminium trifluoride is employed.Type: GrantFiled: May 10, 1996Date of Patent: October 21, 1997Assignee: Elf Atochem S.A.Inventors: Serge Hub, Pierre Ravenel
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Patent number: 5637782Abstract: A process for saturating an olefin-containing halogenated organic stream to produce saturated halogenated organic compounds while minimizing the hydrodehalogenation of the organic compounds.Type: GrantFiled: December 2, 1994Date of Patent: June 10, 1997Assignee: UOPInventor: Tom N. Kalnes
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Patent number: 5616821Abstract: Refrigerants, such as Freon.RTM. 12 and other potential ozone depleting substances will be in short supply as their production is phased out, and until existing refrigeration equipment is retrofitted to receive more environmentally friendly refrigerants. Existing supplies of such refrigerants when contaminated with other refrigerants especially chlorofluorohydrocarbons like Freon 22 form azeotropes, which are not readily separated by conventional distillation methods, are selectively decomposed in-situ by reacting with bases such as metal hydroxides in aqueous solutions or compatible organic solvents. The remaining non-reacted refrigerant-containing composition is readily recycled by separation and recovery methods from the reaction mixture to provide a reusable refrigerant composition practically free of contaminating refrigerant.Type: GrantFiled: January 30, 1995Date of Patent: April 1, 1997Assignee: Commodore Laboratories, Inc.Inventors: Robert W. Mouk, Albert E. Abel
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Patent number: 5600041Abstract: A process for treating a stream containing halogenated organic compounds and having trace quantities of organic nitrates to produce a stream comprising halogenated organic compounds free from organic nitrates by the utilization of a hydrogenation zone operated at selective hydrogenation conditions in order to convert the organic nitrates to water-soluble nitrogen compounds while minimizing the production of hydrogen halide compounds. The resulting water-soluble nitrogen compounds are removed by extraction with an aqueous stream.Type: GrantFiled: February 13, 1995Date of Patent: February 4, 1997Assignee: UOPInventors: Chwu-Ching Jan, Tom N. Kalnes, George R. Hibel
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Patent number: 5600037Abstract: 1,1,2-trifluoro-1,2-dichloroethane (Al23a) is isomerized to 1,1,1-tri-fluoro-2,2-dichloroethane (Al23) by contacting it with AlF.sub.3 at temperatures ranging from 180.degree. to 400.degree. C. Advantageously, it is operated with mixtures of Al23a with Al23 and/or other chlorofluorocarbons coming from the preparation of Al23 by hydrofluorination of perchloroethylene.Type: GrantFiled: June 7, 1995Date of Patent: February 4, 1997Assignee: Ausimont S.p.A.Inventors: Paolo Cuzzato, Letanzio Bragante, Antonio Masiero
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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: 5569797Abstract: A process for preparing a hydrochlorofluorocarbon essentially free of olefinic impurities by selectively hydrogenating the olefinic impurities. The process may be controlled such that at least a portion of the hydrochlorofluorocarbon is converted into a fluorohydrocarbon.Type: GrantFiled: January 7, 1992Date of Patent: October 29, 1996Assignee: E. I. Du Pont de Nemours and CompanyInventors: Ta-Wei Fu, Velliyur N. M. Rao
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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: 5563305Abstract: 1,1,1-trifluoro-2-fluoroethane (CFC 134a) is purified from 1,1-difluoro-2-chloroethylene (CFC 1122) by reacting a mixture comprising said compounds with hydrofluoric acid, at temperatures from 200.degree. C. to 450.degree. C., in one presence of chrome oxide (Cr.sub.2 O.sub.3) in substantially crystalline form.Type: GrantFiled: June 6, 1995Date of Patent: October 8, 1996Assignee: Ausimont S.p.A.Inventors: Antonio Masiero, Paolo Cuzzato, Letanzio Bragante
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Patent number: 5560899Abstract: The invention relates to a process for separating HF contained in liquid mixtures comprising HCFC 123 and/or 124. The mixtures, enriched in C.sub.2 Cl.sub.4 up to a content of such compound of 20-75% by weight, is subjected to a treatment for separating liquid phases, thereby obtaining an acid phase very rich in Hf and an organic phase impoverished in HF, which is subjected to a flash, so obtaining a liquid phase containing 123, 124 and C.sub.2 Cl.sub.4, having a very low HF content, and a gas phase enriched in HF. As an alternative to flash, a separation in a distillation column can be carried out.Type: GrantFiled: February 20, 1996Date of Patent: October 1, 1996Assignee: Ausimont S.p.A.Inventors: Giampaolo Solinas, Giampiero Basile