Purification Or Recovery Patents (Class 570/177)
-
Patent number: 7015368Abstract: A purification process of thermoprocessable tetrafluoroethylene (TFE) copolymers comprising the following steps: A) the polymer latex is transformed into gel form, under mechanical stirring, by addition of an acid electrolyte having pH values ?2; B) washing of the polymer gel with aqueous solutions having pH from 1 to 7.Type: GrantFiled: July 26, 2002Date of Patent: March 21, 2006Assignee: Ausimont S.p.A.Inventors: Hua Wu, Vincenzo Arcella
-
Patent number: 6992229Abstract: The present invention has an object to provide a method for purifying a fluorinated hydroxyl compound of the formula 1 safely in a high yield under industrially practical conditions. Namely, a mixture containing a fluorinated hydroxyl compound of Rf—CR1R2—OH (Formula 1, wherein Rf is a C1-20 polyfluoroalkyl group, and each of R1 and R2 is a hydrogen atom or a C1-3 alkyl group) such as 2,2,3,3-tetrafluoropropanol, and a compound having an unshared electron pair, is distilled by heating in the presence of a solid acid catalyst such as a cation exchange resin catalyst, or by adding a proton source such as water.Type: GrantFiled: November 19, 2002Date of Patent: January 31, 2006Assignee: Asahi Glass Company, LimitedInventors: Hidekazu Okamoto, Akihiro Wada, Toshihiko Toma, Nobuyuki Yamagishi
-
Patent number: 6972094Abstract: Upon recovering a fluorochemical surfactant from a fluorochemical-containing aqueous solution, there is provided a method for recovering the fluorochemical surfactant from the aqueous solution containing the surfactant. In the method, the fluorochemical surfactant is recovered by subjecting the aqueous solution containing the fluorochemical surfactant to a filtration treatment step with a reverse osmosis membrane so as to obtain from the aqueous solution, a concentrated aqueous solution in which the concentration of the fluorochemical surfactant is increased.Type: GrantFiled: August 8, 2001Date of Patent: December 6, 2005Assignee: Daikin Industries, Ltd.Inventors: Takuya Ichida, Masahiro Kondo
-
Patent number: 6967260Abstract: Tetrafluoromethane containing ethylene compound, hydrocarbon compounds, carbon monoxide and/or carbon dioxide is contacted with zeolite having an average pore size of 3.4 to 11 ? and an Si/Al ratio of 1.5 or less and/or a carbonaceous adsorbent having an average pore size of 3.4 to 11 ?. Thus, high-purity tetrafluoromethane can be obtained which is advantageous in industry and provides good profitability.Type: GrantFiled: April 26, 2001Date of Patent: November 22, 2005Assignee: Showa Denko K.K.Inventors: Hiromoto Ohno, Toshio Ohi
-
Patent number: 6927312Abstract: Disclosed are improved fluorination processes and fluorine-containing compositions which involve introducing to one or more fluorination process compositions a water reactive agent in an amount and under conditions effective to decrease the amount of water in that composition. The water reactive agent is preferably introduced to the fluorination reaction process at a location proximate to the site of the fluorination reaction, or upstream of the fluorination reaction, in amounts and under conditions effective to produce a relatively lower concentration of water in the composition, and preferably throughout the fluorination process.Type: GrantFiled: November 12, 2003Date of Patent: August 9, 2005Assignee: Honeywell International Inc.Inventors: Jason T. Stuck, Hsueh Sung Tung, Michael Van Der Puy, Timothy R. Demmin, Franklin S. Wong, Andrew J. Poss, Matthew H. Luly
-
Patent number: 6900362Abstract: A process for the production of HFC-227ea from HF and HFP is provided. This process takes advantage of an azeotropic composition of HF and HFC-227ea in order to produce HFC-227ea essentially free of HF and recycle unreacted HF back to the reactor. The recycle of said azeotropic composition, also allows the use of HFC-227ea as a diluent to aid in control of reactor temperature for a highly exothermic reaction.Type: GrantFiled: October 31, 2002Date of Patent: May 31, 2005Assignee: E. I. du Pont de Nemours and CompanyInventors: Ralph Newton Miller, Mario J. Nappa, Donald J. Toton
-
Patent number: 6897344Abstract: Divalent and trivalent metal salts are added to the solution containing the fluorine compound to precipitate the layered double hydroxide containing the fluorine compound between layers. By these processes, the fluorine compound can be fixed with high rate. Moreover, if necessary, the precipitated layered double hydroxide can be recovered to separate the fluorine compound or its salt between layers. Therefore, the burden to environment or the ecosystem by the fluorine compound can be reduced.Type: GrantFiled: July 26, 2001Date of Patent: May 24, 2005Assignee: Jemco Inc.Inventors: Kiyoshi Fuda, Toshiaki Matsunaga, Takeshi Kamiya, Kota Omori
-
Patent number: 6849772Abstract: 1,1-Difluoroethane containing less than 10 mg/kg of vinyl chloride is obtained by treatment, with hydrogen fluoride, of a crude 1,1-difluoroethane containing less than 1 mol of hydrogen chloride per mole of 1,1-difluoroethane.Type: GrantFiled: October 7, 2002Date of Patent: February 1, 2005Assignee: Solvay (Societe Anonyme)Inventors: Charles-Marie Anciaux, Vincent Wilmet, Dominique Lecroc
-
Patent number: 6825043Abstract: A method of increasing the fluorous nature of a compound includes the step of reacting the compound with at least one second compound having the formula: wherein Rf is a fluorous group, Rs is a spacer group, d is 1 or 0, m is 1, 2 or 3, Ra is an alkyl group and X is a suitable leaving group. A compound has the formula: wherein Rf is a fluorous group, n is an integer between 0 and 6, m is 1, 2 or 3, Ra is an alkyl group and X is a leaving group.Type: GrantFiled: May 5, 2000Date of Patent: November 30, 2004Assignee: University of PittsburghInventors: Dennis P. Curran, Roger Read, Zhiyong Luo
-
Publication number: 20040236161Abstract: The present invention relates to processes for reducing the concentration of acidic impurities HF, HCl, HBr, HI, HNO3 and H2SO4 in fluorinated hydrocarbons. The process involves: (i) contacting the fluorinated hydrocarbon with a phosphorous oxyacid salt, and (ii) recovering the fluorinated hydrocarbon having reduced concentration of, or substantially free of, said acidic contaminant, provided that said fluorinated hydrocarbon is not CF3CH2CF3 or CF3CHFCF3.Type: ApplicationFiled: May 23, 2003Publication date: November 25, 2004Inventors: Velliyur Nott Mallikarjuna Rao, Allen C. Sievert
-
Publication number: 20040236162Abstract: Process for the obtention of HFC-227ea having a reduced content of organic impurities, comprising at least subjecting a crude HFC-227ea to two distillation steps at different pressures.Type: ApplicationFiled: March 5, 2004Publication date: November 25, 2004Inventors: Thomas Muller, Dominique Balthasart, Bernd Kutzner
-
Patent number: 6787678Abstract: Disclosed are improved fluorination processes and fluorine-containing compositions which involve introducing to one or more fluorination process compositions a water reactive agent in an amount and under conditions effective to decrease the amount of water in that composition. The water reactive agent is preferably introduced to the fluorination process at a location downstream of the fluorination reaction, in amounts and under conditions effective to produce a relatively lower concentration of water in the composition, and preferably throughout the fluorination process.Type: GrantFiled: December 11, 2003Date of Patent: September 7, 2004Assignee: Honeywell International Inc.Inventors: Hsueh Sung Tung, Jason T. Stuck
-
Publication number: 20040167366Abstract: A process is disclosed for purifying a hydrofluoropropane of undesirable C2-C4 olefinic and C1-C4 saturated chlorinated impurities, comprising the steps of: contacting a first mixture of hydrofluoropropane, olefinic impurity and saturated chlorinated impurity with hydrogen and hydrogen fluoride concurrently in the presence of a bifunctional catalyst, for example an alloy of gold and palladium supported on carbon, capable of catalyzing hydrogenation and fluorination. During the contacting step, olefinic impurity is converted to saturated hydrogenated derivative and/or saturated hydrofluorinated derivativ, and saturated chlorinated impurity is converted to a saturated hydrodechlorinated derivative and/or saturated fluorinated derivative. The hydrofluoropropane thus formed is substantially free of both the olefinic and saturated chlorinated impurities and may be used as obtained or subject to further purification steps such as distillation to remove the process derivatives (e.g.Type: ApplicationFiled: December 11, 2003Publication date: August 26, 2004Inventors: Velliyur Nott Mallikarjuna Rao, Allen C. Sievert
-
Patent number: 6774270Abstract: A method of removing hexafluoropropylene dimers (“HFP dimers”), dimer hydrides and other oligomers from a fluid is described. The method comprises heating the fluid to isomerize the HFP dimers to the thermodynamic isomer, and contacting the fluid with a tertiary amine (or salts thereof) to form a hexafluoropropylene dimer—tertiary amine adduct. The method may further comprise the step of separating the dimer adducts from the reaction mixture.Type: GrantFiled: April 1, 2003Date of Patent: August 10, 2004Assignee: 3M Innovative Properties CompanyInventors: Zhongxing Zhang, Zai-Ming Qiu, Daniel R. Vitcak, Richard M. Flynn
-
Publication number: 20040133051Abstract: A process for removing one or more unsaturated halocarbons from a halocarbon mixture comprising one or more unsaturated halocarbons and one or more saturated halocarbons, which process comprises contacting the halocarbon mixture with a mixture of a solid chemical oxidant and a solid support in the presence of water.Type: ApplicationFiled: February 5, 2004Publication date: July 8, 2004Inventors: Stephen Andrew Flaherty, Paul Hendry Stewart
-
Patent number: 6743957Abstract: Divalent and trivalent metal salts are added to the solution containing the fluorine compound and the polymer containing fluorine to precipitate the layered double hydroxide containing the fluorine compound between layers. At this time, the polymer containing fluorine suspended in the solution is also coagulated to precipitate. By these processes, the fluorine compound is fixed with high rate to separate from the solution with the polymer containing fluorine, and recovered if necessary. By this treatment process, the fluorine compound and the polymer containing fluorine, contained in the wastewater etc. can be separated easily, and the burden to environment or ecosystem can be reduced.Type: GrantFiled: June 26, 2002Date of Patent: June 1, 2004Assignee: JEMCO, Inc.Inventors: Kiyoshi Fuda, Toshiaki Matsunaga, Takeshi Na Kamiya, Kota Omori
-
Patent number: 6720465Abstract: A process for preparing purified, saturated, partially fluorinated or perfluorinated hydrocarbon compounds from crude products which are contaminated with impurity compounds which absorb light at a wavelength of &lgr;>200 nm by irradiating the crude product with UV radiation of a wavelength of &lgr;>200 nm and thereafter recovering highly pure, partially fluorinated or perfluorinated hydrocarbon compounds from the irradiated reaction product, for example, by simple vacuum distillation.Type: GrantFiled: March 4, 2002Date of Patent: April 13, 2004Assignee: Solvay Fluor und Derivate GmbHInventors: Max Braun, Carsten Brosch, Heinz Gress
-
Patent number: 6710216Abstract: In a closed-loop biomass extraction apparatus (10), strategies for purifying HFC solvents used therein include: (i) contacting an adsorbent and a desiccant, e.g. in a container (26) with contaminated HFC solvent branched from the main flow loop; and, optionally, (ii) washing contaminated HFC solvent with water, e.g. in a vessel (34) to separate a co-solvent or entrainer, such as ethanol, thereform.Type: GrantFiled: September 5, 2000Date of Patent: March 23, 2004Assignee: Imperial Chemical Industries PLCInventors: Stuart Corr, Paul A. Dowdle, Robert E. Low, James David Morrison, Frederick Thomas Murphy
-
Patent number: 6673264Abstract: The invention relates to azeotropic and azeotrope-like mixtures of 1,1,1,3,3-pentafluorobutane (HFC-365) and hydrogen fluoride and a process for separating the azeotrope-like mixtures. The compositions of the invention are useful as an intermediate in the production of HFC-365. The latter is useful as a nontoxic, zero ozone depleting fluorocarbon useful as a solvent, blowing agent, refrigerant, cleaning agent and aerosol to propellant.Type: GrantFiled: June 3, 2002Date of Patent: January 6, 2004Assignee: Honeywell International Inc.Inventors: Hang T. Pham, Rajiv R. Singh, Hsueh S. Tung
-
Patent number: 6660893Abstract: A process for separating and recovering hydrogen fluoride from a mixture with an organic compound especially a fluorine-containing compound by extraction with a solution of an alkali metal fluoride in hydrogen fluoride, phase separation and recovery. A process for producing a fluorine-containing organic compound by fluorinating a starting material with hydrogen fluoride and similarly recovering hydrogen fluoride from the product stream. The solution may be anhydrous or aqueous.Type: GrantFiled: June 5, 2001Date of Patent: December 9, 2003Assignee: Ineca Fluor Holdings LimitedInventors: Paul Nicholas Ewing, Charles John Shields, Christopher Roberts
-
Patent number: 6646171Abstract: A process for the crystallisation of a sterically hindered organic compound from a saturated or supersaturated solution of said compound in a solvent therefor, characterised in that crystallisation is effected under elevated pressure at a temperature above the boiling point of said solution at atmospheric pressure and up to the boiling point of said solution at said elevated pressure.Type: GrantFiled: November 13, 2001Date of Patent: November 11, 2003Assignee: Amersham Health ASInventor: Jan Cervenka
-
Patent number: 6642415Abstract: Fluorinated emulsifiers, in particular, perfluorooctanoic acid are bound to anionic exchange resins for the purification of aqueous effluent from the production of fluoropolymers. Said emulsifiers may be quantitatively eluted from the exchanger with a water-miscible organic solvent, containing a small amount of ammonia. It is of advantage to distil off the ammonia containing solvent, recycle the emulsifier to a further polymerization and recycle the ammoniacal solvent for elution. Addition of alkalis improves the elution efficiency.Type: GrantFiled: April 12, 2002Date of Patent: November 4, 2003Assignee: 3M Innovative Properties CompanyInventors: Stephan Führer, Klaus Hintzer, Gernot Löhr, Werner Schwertfeger
-
Publication number: 20030164283Abstract: The present invention involves processes that utilize an olefinic compound, in particular, hexafluoropropene (HFP) or chlorotrifluoroethene (CFC-1113) as extracting agents in the purification of pentafluoroethane (HFC-125). These processes can utilize recovered HFP as a precursor for the production of heptafluoropropane (HFC-227) or other derivatives.Type: ApplicationFiled: February 14, 2002Publication date: September 4, 2003Inventors: Stephan M. Brandstater, Mitchel Cohn, Victoria E. Hedrick, Yuichi Iikubo
-
Publication number: 20030121769Abstract: The invention relates to the purification of pentafluoroethane (F125) containing chloropentafluoroethane (F115) by liquid/liquid extraction or by extractive distillation.Type: ApplicationFiled: September 16, 2002Publication date: July 3, 2003Inventors: Emmanuel Guiraud, Cathy Descamps
-
Patent number: 6555086Abstract: Processes for separating and recovering hydrogen fluoride from a gaseous mixture of an organic compound and hydrogen fluoride are disclosed. The processes include contacting the gaseous mixture with a solution of an alkali metal fluoride in hydrogen fluoride, separating a gas phase depleted in hydrogen fluoride and containing the organic compound from a liquid phase, and recovering hydrogen fluoride from the liquid phase.Type: GrantFiled: October 7, 1999Date of Patent: April 29, 2003Assignee: Ineos Fluor Holdings LimitedInventors: Paul Nicholas Ewing, Charles John Shields, Robert Elliott Low
-
Patent number: 6552238Abstract: Provided is a method and system for separating heavy ends from a halogenated alkane in a waste stream. The method includes: (a) removing a bottom fraction containing heavy ends from a catalyst recovery unit and conveying the bottom fraction to a vessel; (b) introducing steam into the bottom fraction containing heavy ends; (c) removing a halogenated alkane vapor and a water vapor from the waste treatment unit; (d) condensing the halogenated alkane and water vapors; and (e) separating the halogenated alkane phase and water phase from the heavy ends.Type: GrantFiled: August 31, 2001Date of Patent: April 22, 2003Assignee: Vulcan ChemicalsInventors: Eric L. Mainz, Richard L. Wilson
-
Patent number: 6540882Abstract: The invention relates to a process of separation of mixtures containing HFC-365mfc/HF azeotropic compositions by two distillations at different pressures, as well as to a process of synthesis of HFC-365mfc which integrates this process of separation and a recycling of certain fractions towards the hydrofluorination step.Type: GrantFiled: March 22, 2000Date of Patent: April 1, 2003Assignee: Solvay (Societe Anonyme)Inventors: Ferdinand Reif, Dominique Balthasart
-
Patent number: 6521803Abstract: Process for the separation of a mixture comprising at least one hydrofluoroalkane and hydrogen fluoride, according to which a hydrofluoroalkane/hydrogen fluoride mixture is reacted with at least one chlorinated or chlorofluorinated precursor of the hydrofluoroalkane. Process for the preparation of a hydrofluoroalkane comprising such a separation, in combination with a catalytic reaction stage. Azeotropic compositions.Type: GrantFiled: July 17, 2001Date of Patent: February 18, 2003Assignee: Solvay (Societe Anonyme)Inventors: Alain Lambert, Vincent Wilmet
-
Patent number: 6521461Abstract: 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 wherein A=F or Rf; X=H, F, Cl, Rf, or YRf; Z= H, F, Cl, or Rf; 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 Rf is independently selected from the group consisting of highly fluorinated or perfluorinated alkyl groups; and a combination of any two Rf groups can be linked to form a cyclic structure. The Rf alkyl chains may contain from 1-20 carbon atoms, with 1-12 carbon atoms preferred.Type: GrantFiled: June 14, 2001Date of Patent: February 18, 2003Assignee: 3M Innovative Properties CompanyInventors: Mark Eugene Mueller, Donald Frederick Hagen, Yuri Cheburkov, Fred Lynn DeRoos, Glenn Delmont Johnson, John Stephen Marhevka, Venkateswarlu Pothapragada
-
Patent number: 6512150Abstract: A gaseous process for reducing the amount of chloropentafluoroethane (CFC 115) impurity present in pentafluoroethane (HFC 125) characterized in that pentafluroethane is allowed to flow on a catalyst formed by a trivalent chromium salt, optionally supported, at temperatures in the range 200° C.-400° C., obtaining the reaction of chloropentafluoroethane with pentafluoroethane with formation of hexafluoroethane (FC 116) and tetrafluorochloroethane (HCFC 124).Type: GrantFiled: July 17, 2000Date of Patent: January 28, 2003Assignee: Ausimont S.p.A.Inventors: Paolo Cuzzato, Sergio Peron
-
Patent number: 6500994Abstract: A process for purification of 1,1,1,3,3-pentafluorobutane (HFC-365mfc) containing a decreased amount of hydrogen chloride, hydrogen fluoride and/or unsaturated impurities. To this end crude 1,1,1,3,3-pentafluorobutane is treated in the liquid phase with a solid, inorganic sorption agent and/or with diatomic molecules which and to C—C multiple bonds. The product to be purified is preferably treated with elemental fluorine. The contents of hydrogen chloride and hydrogen can each be decreased to below 1 ppm. The content of unsaturated (chlorine)-fluorine-compounds can be decreased to below 20 ppm, and the content of unsaturated C2 compounds can be decreased to below 10 ppm. It has also been discovered that fluorotrichloroethylene can be used as a control substance to monitor the purification of 1,1,1,3,3-pentafluorobutane.Type: GrantFiled: June 8, 2001Date of Patent: December 31, 2002Assignee: Solvay Fluor und Derivate GmbHInventors: Carsten Brosch, Heinz Gress, Matthias Rieland
-
Patent number: 6489277Abstract: In order to replace 1,1,2-trichloro-1,2,2-trifluoroethane and 1,1-dichloro-1-fluoroethane in compositions for treating solid surfaces (in particular defluxing), the invention proposes the use of a quasi-azeotropic mixture containing, by weight, from 75 to 95% of 1,1,1,3,3-pentafluorobutane, from 1 to 15% of methylene chloride and from 1 to 10% of methanol.Type: GrantFiled: September 26, 2000Date of Patent: December 3, 2002Assignee: Elf Atochem S.A.Inventor: Pascal Michaud
-
Patent number: 6489523Abstract: The present invention intends to provide a process for producing CF3CF3 with good profitability using CF3CHF2 containing a compound having chlorine atom within the molecule, and use thereof. In the process of the present invention, a gas mixture containing CF3CHF2 and a compound having chlorine atom within the molecule is reacted with hydrogen fluoride in the presence of a fluorination catalyst, thereby converting CClF2CF3 as a main impurity into CF3CF3, and CF3CHF2 containing CF3CF3 is reacted with fluorine gas in the gaseous phase in the presence of a diluting gas.Type: GrantFiled: January 14, 2002Date of Patent: December 3, 2002Assignee: Showa Denko K.K.Inventors: Hiromoto Ohno, Kazunari Kaga, Toshio Ohi
-
Publication number: 20020157938Abstract: A method for isolating 32 from a crude mixture containing HCl and an azeotropic mixture of 32 and HF is provided without the need to isolate any HF azeotrope.Type: ApplicationFiled: April 25, 2001Publication date: October 31, 2002Inventor: John A. Wismer
-
Publication number: 20020157940Abstract: A process for preparing purified, saturated, partially fluorinated or perfluorinated hydrocarbon compounds from crude products which are contaminated with impurity compounds which absorb light at a wavelength of &lgr;>200 nm by irradiating the crude product with UV radiation of a wavelength of &lgr;>200 nm and thereafter recovering highly pure, partially fluorinated or perfluorinated hydrocarbon compounds from the irradiated reaction product, for example, by simple vacuum distillation.Type: ApplicationFiled: March 4, 2002Publication date: October 31, 2002Inventors: Max Braun, Carsten Brosch, Heinz Gress
-
Publication number: 20020156331Abstract: A process for recovery of hydrogen fluoride comprises contacting a gaseous mixture containing hydrogen fluoride and an organic compound with a solution of an alkali metal fluoride in hydrogen fluoride, separating a gas phase depleted in hydrogen fluoride and containing the organic compound from a liquid phase enriched in hydrogen fluoride, and then recovering the hydrogen fluoride from the liquid phase.Type: ApplicationFiled: October 7, 1999Publication date: October 24, 2002Inventors: PAUL NICHOLAS EWING, CHARLES JOHN SHIELDS, ROBERT ELLIOTT LOW
-
Patent number: 6437202Abstract: 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 wherein A=F or Rf; X=H, F, Cl, Rf, or YRf; Z=H, F, Cl, or Rf; 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 Rf is independently selected from the group consisting of highly fluorinated or perfluorinated alkyl groups; and a combination of any two Rf groups can be linked to form a cyclic structure. The Rf alkyl chains may contain from 1-20 carbon atoms, with 1-12 carbon atoms preferred.Type: GrantFiled: June 13, 2001Date of Patent: August 20, 2002Assignee: 3M Innovative Properties CompanyInventors: Mark Eugene Mueller, Donald Frederick Hagen, Yuri Cheburkov, Fred Lynn DeRoos, Glenn Delmont Johnson, John Stephen Marhevka, Venkateswarlu Pothapragada
-
Patent number: 6437168Abstract: A method for efficiently extracting a reaction product containing a target aromatic fluorine compound formed by the halogen exchange reaction of an aromatic chlorine compound with a fluorinating agent quickly from the reaction vessel without suffering part of the reaction product to remain as a residue inside the reaction vessel is disclosed. Specifically, the reaction product is extracted from the reactor subsequently to the halogen exchange reaction at a temperature in the range of 20-250° C. By this method, the reaction product formed in consequence of the halogen exchange reaction can be efficiently extracted quickly from the reaction vessel, and that without suffering occurrence of a residue of the reaction product.Type: GrantFiled: August 29, 2001Date of Patent: August 20, 2002Assignee: Nippon Shokubai Co., Ltd.Inventor: Kouichi Hirota
-
Patent number: 6414203Abstract: A method for reducing the content of unsaturated impurities contained in 1,1,1,3,3-pentafluoropropane (R245fa), while maintaining the loss of R245fa at a minimum level. R245fa containing unsaturated impurities is contacted in a gas phase with chlorine gas in the presence of an activated carbon catalyst, thereby converting the unsaturated impurities to the chlorine addition compounds to reduce the content of the unsaturated impurities.Type: GrantFiled: May 9, 2001Date of Patent: July 2, 2002Assignee: Asahi Glass Company, LimitedInventors: Hidekazu Okamoto, Keiichi Ohnishi
-
Publication number: 20020077513Abstract: In the synthesis of 1,1,1,3,3-pentafluorobutane (R-365mfc), a mixture of R-365mfc and the impurity 1-chloro-3,3,3-trifluoropropene (R-1354zd) is purified and R-1354zd is removed from the mixture by contacting the mixture with 1-5 mols of chlorine for each mol of R-1354zd 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-1354zd is reduced to below 10 wt. ppm as it is converted to 2,3-dichloro-1,1,1,3-tetrafluorobutane (R-354) or other butane containing more chlorine and having a higher boiling point than R-365mfc. The butane(s) may be separated more easily from R-365mfc. The photochlorination is effected in a manner such that at least about 96 weight percent of the starting amount of R-365mfc is maintained in the mixture.Type: ApplicationFiled: December 15, 2000Publication date: June 20, 2002Inventors: Stephen Frederic Yates, Hsueh Sung Tung
-
Patent number: 6403849Abstract: A method for obtaining purified perfluorocarbon compositions, and purified compositions containing such perfluorocarbons.Type: GrantFiled: September 26, 2000Date of Patent: June 11, 2002Assignee: 3M Innovative Properties CompanyInventors: Zai-Ming Qiu, Zhongxing Zhang
-
Patent number: 6399841Abstract: Hydrogen fluoride is separated from its mixtures with 1,1,1,3,3-pentafluorobutane by extraction using an organic solvent containing a 1,1,1,3,3-chloro(fluoro)butane.Type: GrantFiled: September 24, 2001Date of Patent: June 4, 2002Assignee: Solvay (Societe Anonyme)Inventors: Alain Lambert, Vincent Wilmet
-
Patent number: 6395941Abstract: In order to remove the impurities (in particular 1-chloro-2,2-difluoroethylene) present in crude 1,1,1,2-tetrafluoroethane (F134a), a gaseous mixture of crude F134a and hydrofluoric acid is treated in the gas phase, in the presence of a fluorination catalyst, at a temperature of between 200 and 380° C. and under a pressure between atmospheric pressure and 2.5 MPa, the HF/F134a molar ratio being between 0.05 and 0.5.Type: GrantFiled: July 3, 1997Date of Patent: May 28, 2002Assignee: Elf Atochem, S.A.Inventors: Bernard Cheminal, Andre Lantz
-
Publication number: 20020040172Abstract: The invention relates to the purification of pentafluoroethane (F125) containing chloropentafluoroethane (F115) by liquid/liquid extraction or by extractive distillation.Type: ApplicationFiled: June 26, 2001Publication date: April 4, 2002Inventors: Emmanuel Guiraud, Cathy Descamps
-
Publication number: 20020035300Abstract: A process is disclosed for producing the pentafluoropropenes of the formula CF 3 CX═CF 2 , where X is H or Cl. The process involves hydrodehalogenating CF 3 CCl 2 CF 3 with hydrogen at an elevated temperature in the vapor phase over a catalyst comprising an elemental metal, metal oxide, metal halide and/or metal oxyhalide (the metal being copper, nickel, chromium and the halogen of said halides and said oxyhalides being fluorine and/or chlorine).Type: ApplicationFiled: August 19, 1999Publication date: March 21, 2002Inventors: V.N. MALLIKARJUNA RAO, ALLEN CAPRON SIEVERT
-
Publication number: 20020010373Abstract: The invention relates to a process for purifying a crude 1,1,1,5,5,5-hexafluoroacetylacetone dihydrate containing an impurity. The process includes bringing the crude 1,1,1,5,5,5-hexafluoroacetylacetone dihydrate into contact with a poor solvent in which 1,1,1,5,5,5-hexafluoroacetylacetone dihydrate is substantially insoluble, thereby removing the impurity from the crude 1,1,1,5,5,5-hexafluoroacetylacetone dihydrate. Alternatively, the process includes precipitating crystals of 1,1,1,5,5,5-hexafluoroacetylacetone dihydrate from a solution of the crude 1,1,1,5,5,5-hexafluoroacetylacetone dihydrate. Thus, it is possible to produce 1,1,1,5,5,5-hexafluoroacetylacetone dihydrate of high purity. This product makes it easy to produce 1,1,1,5,5,5-hexafluoroacetylacetone of high purity.Type: ApplicationFiled: December 21, 2000Publication date: January 24, 2002Inventors: Takeo Komata, Nariaki Ii, Yoshiki Hirotsu
-
Patent number: 6340781Abstract: A process for the removal of chloroalkane, chlorofluoroalkane and/or hydrofluoroalkane impurities from pentafluoroethane which comprises contacting the impure pentafluoroethane with hydrogen at elevated temperature in the presence of a hydrogenation catalyst to convert the impurity or impurities to a hydrofluoroalkane and/or a hydrocarbon and separating the resulting hydrofluoroalkane and/or hydrocarbon from the pentafluoroethane.Type: GrantFiled: April 3, 1995Date of Patent: January 22, 2002Assignee: Imperial Chemical Industries PLCInventors: Charles John Shields, Gary Goodyear
-
Publication number: 20020007099Abstract: 1,1-Difluoroethane containing less than 10 mg/kg of vinyl chloride is obtained by treatment, with hydrogen fluoride, of a crude 1,1-difluoroethane containing less than 1 mol of hydrogen chloride per mole of 1,1-difluoroethane.Type: ApplicationFiled: November 30, 1998Publication date: January 17, 2002Inventors: CHARLES-MARIE ANCIAUX, VINCENT WILMET, DOMINIQUE LECROC
-
Patent number: 6333440Abstract: A process is disclosed for obtaining octafluorocyclobutane of increased purity from a mixture comprising (a) octafluorocyclobutane and (b) at least one halocarbon impurity which is difficult to separate from octafluorocyclobutane by distillation (e.g., azeotropes of octafluorocyclobutane with such halocarbons). The process involves (1) contacting the mixture with a catalyst in the vapor phase in the presence HCl and/or HF at a temperature sufficient to react component (b) impurity with HCl and/or HF to provide a product mixture comprising halogenated product which is more easily separated from octafluorocyclobutane by distillation than the unreacted impurity; and (2) separating halogenated product obtained in (1) from octafluorocyclobutane by distillation.Type: GrantFiled: April 4, 2001Date of Patent: December 25, 2001Assignee: E. I. du Pont de Nemours and CompanyInventor: V. N. Malikarjuna
-
Patent number: 6328907Abstract: There is provided an azeotropic mixture consisting substantially of 1,1,1, 3,3-pentafluoropropane and hydrogen fluoride. Further, there is provided a process of separating/purifying R-245fa and/or HF from a mixture comprising R-245fa and HF wherein the mixture comprising 1,1,1,3,3-pentafluoropropane and hydrogen fluoride is subjected to a distillation step so that a distillate is obtained which comprises the azeotropic mixture consisting substantially of 1,1,1,3,3-pentafluoropropane and hydrogen fluoride, and a bottom product is obtained which comprises separated/purified 1,1,1,3,3-pentafluoropropane or hydrogen fluoride.Type: GrantFiled: July 23, 1998Date of Patent: December 11, 2001Assignee: Daikin Industries, Ltd.Inventors: Tatsuo Nakada, Noriaki Shibata, Takashi Shibanuma