- Metal-free dehydrogenation of tri- and diethylamine with (C2F5)3PF2
-
The reaction of the strong Lewis acid (C2F5)3PF2 with triethylamine leads to an initial hydride abstraction, resulting in the formation of the hydridophosphate anion [P(C2F5)3F2H]? and the iminium ion [CH3CH = NEt2]+. The latter is deprotonated by a second molecule NEt3 which corresponds to a formal hydrogen abstraction from the amine. The resulting nucleophilic enamine is trapped by a second equivalent of (C2F5)3PF2, ultimately yielding the β-aminovinylphosphorane derivative (C2F5)2PF2C2H2NEt2. The β-aminovinylphosphorane reacts with CsF to the corresponding trifluorophosphate derivative, [P(C2F5)2F3C2H2NEt2]?, which hydrolyzes to the aldehyde [P(C2F5)2F3CH2CHO]?, while the reaction with anhydrous HF yields the zwitterionic species [P(C2F5)2F3C2H3NEt2].
- Bader, Julia,Neumann, Beate,Stammler, Hans-Georg,Ignat'ev, Nikolai,Hoge, Berthold
-
-
Read Online
- Kinetics of gaseous fluorination of 1,1,1,2-tetrafluoroethane with elemental fluorine
-
The kinetics and temperature dependence of gaseous fluorination of 1,1,1,2-tetrafluoroethane (TFE) with elemental fluorine have been investigated between 105-148°C. Experiments were conducted in a stationary isothermic regime in copper tubes. Undiluted fluorine was used in a mixture with 1,1,1,2-TFE in concentration from 4% to 10% by volume. Explanations of observed mechanisms are suggested on the basis of the theory of chain reactions.
- Pashkevich,Muhortov,Podpalkina,Barabanov
-
-
Read Online
- Preparation of 1,1,1,2-tetrafluoroethane by the vapor-phase catalytic reaction of 1,1,1-trifluoro-2-chloroethane with anhydrous hydrogen fluoride
-
1,1,1,2-Tetrafluoroethane was prepared in 97% selectivity by the vapor-phase catalytic reaction of 1,1,1-trifluoro-2-chloroethane with anhydrous hydrogen fluoride (AHF) over a metal fluoride catalyst (CrF3 and CoF2) supported on porous aluminum fluoride (PAF). The relationship between the crystalline phase transition of porous aluminum fluoride and temperature from 100 to 640°C was investigated by X-ray diffraction.
- Quan, Heng-Dao,Yang, Hui-E,Li, Zhong,Ren, Jian-Zhang,Li, Hui-Li
-
-
Read Online
- Production of fluorinated ethanes using elemental fluorine
-
Scientific principles of industrial gas-phase fluorination of fluoroethanes with elemental fluorine were developed. Conditions for fluorination of low-fluorinated ethanes without rupture of the C-C bond were determined.
- Pashkevich,Mukhortov,Alekseev,Asovich
-
-
Read Online
- Pretreatment effect on the properties of the Cr–Mg catalyst for the gas-phase hydrofluorination of perchloroethylene into pentafluoroethane
-
The effect of the temperature of thermal pretreatment of the precursors of the Cr–Mg catalyst on its physicochemical properties (specific surface area and elemental composition) and catalytic properties has been experimentally investigated. The dehydration of the precursor takes place up to a temperature of ~500°С, making it possible to tune the catalyst composition by varying the heat-treatment temperature. The samples prepared from precursors with various compositions differ in their specific surface area and catalytic activity. The highest activity is shown by the catalyst prepared by heat treatment of the precursor at 330°С.
- Petrov,Zirka,Reshetnikov
-
-
Read Online
- Gas-phase fluorination of fluoroethanes with elemental fluorine
-
Scientific basis for industrial gas-phase fluorination of fluoroethanes with elemental fluorine allowing production of higher-fluorinated fluoroethanes from lower-fluorinated compounds is developed. 2001 MAIK "Nauka/Interperiodica".
- Pashkevich,Mukhortov,Alekseev,Asovich,Rozhdestvenskaya
-
-
Read Online
- Nitrogen trifluoride as an oxidative co-reagent in high temperature vapor phase hydrofluorinations
-
Nitrogen trifluoride (NF3) has proven to be a useful additive in high temperature vapor phase hydrofluorination reactions of chlorocarbons. The activity of chromium-based catalysts is maintained by introducing a co-stream of NF3 into the reagent chlorocarbon and HF stream. NF3 is a desirable additive instead of O2 as there is no water generation due to its use.
- Belter, Randolph K.,Sweval, Mark S.,Iikubo, Yuichi
-
-
Read Online
- Catalytic performance of nitrogen-doped activated carbon supported Pd catalyst for hydrodechlorination of 2,4-dichlorophenol or chloropentafluoroethane
-
Nitrogen-doped activated carbon (N-AC) obtained through the thermal treatment of a mixture of HNO3-pretreated activated carbon (AC) and urea under N2 atmosphere at 600 ?C was used as the carrier of Pd catalyst for both liquid-phase hydrodechlorination of 2,4-dichlorophenol (2,4-DCP) and gas-phase hydrodechlorination of chloropentafluoroethane (R-115). The effects of nitrogen doping on the dispersion and stability of Pd, atomic ratio of Pd/Pd2+ on the surface of the catalyzer, the catalyst’s hydrodechlorination activity, as well as the stability of N species in two different reaction systems were investigated. Our results suggest that, despite no improvement in the dispersion of Pd, nitrogen doping may significantly raise the atomic ratio of Pd/Pd2+ on the catalyst surface, with a value of 1.2 on Pd/AC but 2.2 on Pd/N-AC. Three types of N species, namely graphitic, pyridinic, and pyrrolic nitrogen, were observed on the surface of Pd/N-AC, and graphitic nitrogen was stable in both liquid-phase hydrodechlorination of 2,4-DCP and gas-phase hydrodechlorination of R-115, with pyridinic and pyrrolic nitrogen being unstable during gas-phase hydrodechlorination of R-115. As a result, the average size of Pd nanocrystals on Pd/N-AC was almost kept unchanged after liquid-phase hydrodechlorination of 2,4-DCP, whereas crystal growth of Pd was clearly observed on Pd/N-AC after gas-phase hydrodechlorination of R-115. The activity test revealed that Pd/N-AC exhibited a much better performance than Pd/AC in liquid-phase hydrodechlorination of 2,4-DCP, probably due to the enhanced stability of Pd exposed to the environment resulting from nitrogen doping as suggested by the higher atomic ratio of Pd/Pd2+ on the catalyst surface. In the gas-phase hydrodechlorination of R-115, however, a more rapid deactivation phenomenon occurred on Pd/N-AC than on Pd/AC despite a higher activity initially observed on Pd/N-AC, hinting that the stability of pyridinic and pyrrolic nitrogen plays an important role in the determination of catalytic performance of Pd/N-AC.
- Tang, Haodong,Xu, Bin,Xiang, Meng,Chen, Xinxin,Wang, Yao,Liu, Zongjian
-
-
- PROCESS FOR PRODUCING FLUOROETHANE
-
Fluorochromium oxide having a fluorine content of not less than 30 wt.% is used for the fluorination reaction. To provide a manufacturing method for fluorine-containing ethane which contains 1, 1, 1, 2, 2-pentafluoroethane as the main component in which the reaction can be performed while controlling the generation of CFCs to the greatest possible extent by fluorinating at least one selected from the group composed of tetrachloroethylene, 2, 2-dichloro-1, 1, 1-trifluoroethane and 2-chloro-1, 1, 1, 2-tetrafluoroethane with hydrogen fluoride.
- -
-
Paragraph 0046
(2015/12/04)
-
- On the feasibility of nickel-catalyzed trifluoromethylation of aryl halides
-
A computational screening of 42 bidentate phosphines (PP) has yielded promising candidates for Ph-CF3 reductive elimination from Ni(II) complexes of the type [(PP)Ni(Ph)(CF3)]. The computed barriers and synthetic accessibility consid
- Jover, Jess,Miloserdov, Fedor M.,Benet-Buchholz, Jordi,Grushin, Vladimir V.,Maseras, Feliu
-
p. 6531 - 6543
(2015/02/19)
-
- Effects of M-promoter (M = Y, Co, La, Zn) on Cr2O3 catalysts for fluorination of perchloroethylene
-
The vapor phase fluorination of perchloroethylene (PCE) to synthesize 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), 1-chloro-1,2,2,2- tetrafluoroethane (HCFC-124) and pentafluoroethane (HFC-125) was carried out on M-Cr2O3 catalysts with different promoters (M = Y, Co, La, Zn). The catalysts were characterized by X-ray diffraction (XRD), hydrogen temperature-programmed reduction (H2-TPR), Raman spectrum, Ammonia temperature-programmed desorption (NH3-TPD) and X-ray photoelectron spectroscopy (XPS) techniques. It was found that in the pre-fluorination process CrOx (x ≥ 1.5) in M-Cr2O3 catalysts could be transformed into CrOxFy species. The highest activity was obtained on La-Cr2O3(F) catalyst with 90.6% of PCE conversion and 93.7% to total selectivity (HCFC-123 + HCFC-124 + HFC-125) at 300 C. The decline in surface acid sites density of the catalyst could improve the specific reaction rate, and the formation of surface CrOxF y species could enhance the selectivities to HCFC-123, HCFC-124 and HFC-125 for gas phase fluorination of PCE. Copyright - 2013 Published by Elsevier B.V. All rights reserved.
- Cheng, Yong-Xiang,Fan, Jing-Lian,Xie, Zun-Yun,Lu, Ji-Qing,Luo, Meng-Fei
-
-
- Process For The Manufacture Of Pentafluorethane
-
The present invention relates to a process for the manufacture of pentafluoroethane. It more particularly relates to a process for the manufacture of pentafluoroethane by gas-phase fluorination of perchloroethylene (PER) in the presence of a catalyst, characterized in that (i) the reaction of the PER with HF is carried out with an HF/PER molar ratio of greater than or equal to 20 and a pressure of greater than 5 bar absolute, and that (ii) the stream leaving this reaction step is recycled directly to the reaction step after separation of pentafluoroethane and of HCl.
- -
-
Page/Page column 1-2
(2011/04/18)
-
- METHOD FOR PRODUCING PENTAFLUOROETHANE
-
The present invention aims in a method wherein tetrachloroethylene (PCE) is reacted with HF in a gas phase in the presence of a catalyst to obtain pentafluoroethane (HFC-125), to reduce production of undesirable by-products and maintain a catalytic activity at a high level over a long period of time while achieving a high conversion ratio of PCE and suppressing deterioration of the catalyst. In a method for producing pentafluoroethane wherein tetrachloroethylene is reacted with HF in a gas phase in the presence of a catalyst to obtain pentafluoroethane, characterized in that chromium oxyfluoride is disposed in a reactor as the catalyst, and oxygen is fed into the reactor together with tetrachloroethylene and HF, at a amount of 0.4-1.8% by mole with respect to tetrachloroethylene.
- -
-
Page/Page column 5-6
(2010/11/03)
-
- Explored routes to unknown polyfluoroorganyliodine hexafluorides, R FIF6
-
Two routes to RFIF6 compounds were investigated: (a) the substitution of F by RF in IF7 and (b) the fluorine addition to iodine in RFIF4 precursors. For route (a) the reagents C6F5SiMe3, C6F 5SiF3, [NMe4][C6F 5SiF4], C6F5BF2, and 1,4-C6F4(BF2)2 were tested. C 6F5IF4 and CF3CH2IF 4 were used in route (b) and treated with the fluoro-oxidizers IF7, [O2][SbF6]/KF, and K2[NiF 6]/KF. The observed sidestep reactions in case of routes (a) and (b) are discussed. Interaction of C6F5SiX3 (X = Me, F), C6F5BF2, 1,4-C6F 4(BF2)2 with IF7 gave exclusively the corresponding ring fluorination products, perfluorinated cyclohexadiene and cyclohexene derivatives, whereas [NMe4][C6F 5SiF4] and IF7 formed mixtures of C 6FnIF4 and C6FnH compounds (n = 7 and 9). CF3CH2IF4 was not reactive towards the fluoro-oxidizer IF7, whereas C6F 5IF4 formed C6FnIF4 compounds (n = 7 and 9). C6F5IF4 and CF 3CH2IF4 were inert towards [O 2][SbF6] in anhydrous HF. CF3CH 2IF4 underwent C-H fluorination and C-I bond cleavage when treated with K2[NiF6]/KF in HF. The fluorine addition property of IF7 was independently demonstrated in case of perfluorohexenes. C4F9CFCF2 and IF7 underwent oxidative fluorine addition at -30 °C, and the isomers (CF 3)2CFCFCFCF3 (cis and trans) formed very slowly perfluoroisohexanes even at 25 °C. The compatibility of IF7 and selected organic solvents was investigated. The polyfluoroalkanes CF 3CH2CHF2 (PFP), CF3CH 2CF2CH3 (PFB), and C4F9Br are inert towards iodine heptafluoride at 25 °C while CF3CH 2Br was slowly converted to CF3CH2F. Especially PFP and PFB are new suitable organic solvents for IF7.
- Frohn, Hermann-Josef,Bardin, Vadim V.
-
experimental part
p. 1000 - 1006
(2010/11/16)
-
- PROCESS FOR PRODUCING PENTAFLUOROETHANE
-
The present invention relates to a process for producing pentafluoroethane. More particularly, the subject of the invention is a continuous process for producing pentafluoroethane comprising (i) a step of fluorinating perchloroethylene (PER) with hydrofluoric acid, in the gas phase, in the presence of a catalyst, (ii) a step of separating the products issuing from step (i) in order to give a fraction of light products and a fraction of heavy products, comprising hydrofluoric acid, unreacted perchloroethylene and under-fluorinated products, and (iii) a step of pretreating the fraction of heavy products before recycling to step (i).
- -
-
Page/Page column 2-3
(2010/08/22)
-
- PROCESS FOR PREPARING FLUORINE-CONTAINING OLEFIN
-
The present invention provides a process for preparing a fluorine-containing olefin represented by Formula (2): R1CF=CH(R2) wherein R1 is F, H, F(CF2)n-(n is an integer ranging from 1 to 10) or H(CF2)m- (m is an integer ranging from 1 to 10) and R2 is H, F(CF2)n- (n is an integer ranging from 1 to 10) or H(CF2)m- (m is an integer ranging from 1 to 10), the process including a step of reacting a fluorine-containing alcohol represented by Formula (1): R1CF2CH(R2)OH, wherein R1 and R2are the same as above, with a reducing gas in the presence of a specific metal oxide. According to the process of the invention, a desired fluorine-containing olefin can be produced with high selectivity in a single reaction step using a fluorine-containing alcohol as a raw material.
- -
-
Page/Page column 12-13
(2010/08/09)
-
- PROCESSES FOR PRODUCING HYDROHALOCARBON AND HALOCARBON COMPOUNDS USING SILICON TETRAFLUORIDE
-
Methods and systems for producing hydrohalocarbon and/or halocarbon compounds with an inorganic fluoride (e.g., silicon tetrafluoride (SiF4)) are disclosed herein.
- -
-
Page/Page column 5-6
(2009/04/24)
-
- Preparation of trifluoroiodomethane via vapor-phase catalytic reaction between hexafluoropropylene oxide and iodine
-
Based on our previous investigation on the reaction mechanism to produce difluorocarbene and subsequent CF3I starting with CHF3 and I2, a new route for preparing CF3I at a relative low temperature, 200 °C, has b
- Yang, Guang-Cheng,Jia, Xiao-Qing,Pan, Ren-Ming,Quan, Heng-Dao
-
experimental part
p. 985 - 988
(2010/02/28)
-
- Isothermal pyrolysis of iodomethanes in gases
-
The fact was established that the pyrolysis of gaseous iodomethanes RI yields methane and non traces of recombination products R2. A pyrolysis mechanism was proposed and rate constants of limiting stages of the pyrolysis of iodomethane, trideuteroiodomethane, and diiodomethane over the range of 500-1500 K were determined. Pleiades Publishing, Ltd., 2009.
- Skorobogatov,Khripun,Rebrova
-
scheme or table
p. 2641 - 2651
(2010/06/14)
-
- Investigation of CF2 carbene on the surface of activated charcoal in the synthesis of trifluoroiodomethane via vapor-phase catalytic reaction
-
This paper investigates the synthetic mechanism of trifluoroiodomethane (CF3I) in the reaction of trifluoromethane and iodine via vapor-phase catalytic reaction. It is suggested that CF2 carbene is the key intermediate and is formed in the pyrolysis process of CHF3 at high temperature. However, in pyrolysis of CHF3 under activated charcoal (AC) existing conditions, no C2F4 was detected. H2 and 2-methyl-2-butene could not trap the CF2 carbene. When treating the remained compounds on the used AC with H2, CH4 is formed on the process. It is proposed that CF2 carbene combines with AC strongly and transfers into CF3 radical on heat. In addition, it is found that the AC is not only the catalyst supporter to form CF3I, but also a co-catalyst to promote the formation of CF2 carbene and CF3 radical.
- Yang, Guang-Cheng,Lei, Shi,Pan, Ren-Ming,Quan, Heng-Dao
-
experimental part
p. 231 - 235
(2009/08/07)
-
- PROCESSES FOR PRODUCING HYDROFLUOROCARBON COMPOUNDS USING INORGANIC FLUORIDE
-
Methods and systems for producing hydrofluorocarbon with an inorganic fluoride (e.g., germanium tetrafluoride (GeF4)) are disclosed herein.
- -
-
Page/Page column 4
(2008/12/04)
-
- PRODUCTION PROCESSES FOR MAKING 1,1,1,2,2,3-HEXAFLUOROPROPANE
-
A process for making HFC-236cb is disclosed. The process comprises reacting TFE with HFC-32 in the presence of at least one co-product and a suitable catalyst to produce a product mixture comprising HFC-236cb, wherein the total amount of the at least one co-product is at least 10 ppmv based on the total amount of the tetrafluoroethylene, the difluoromethane and the at least one co-product.
- -
-
Page/Page column 12-13
(2008/06/13)
-
- CATALYTIC ADDITION OF HYDROFLUOROCARBONS TO FLUOROOLEFINS
-
A process is disclosed for making RR1R2CCR1R2F wherein R is selected from the group consisting of CH3, CH2F, C2H4F, and F(CF2)nCH2CH2 where n is an integer from 1 to 10, each R1 is independently selected from the group consisting of H, Cl, F and CF3, and each R2 is independently selected from the group consisting of H, F and CF3. The process involves reacting RF with R1R2C=CR1R2 in the presence of SbF5 to produce a product mixture comprising RR1R2CCR1R2F, wherein the reaction temperature is from about -60° C to about -10° C, provided that total number of carbon atoms in R1R2C=CR1R2 is 5 or less.
- -
-
Page/Page column 8-9
(2008/06/13)
-
- Catalytical production processes for making hydrohalopropanes and hydrofluorobutanes
-
A process is disclosed for making hydrohalopropanes or hydrofluorobutanes. The process involves reacting a hydrofluoromethane with a fluoroolefin in the presence of an aluminum catalyst to produce a hydrohalopropane or a hydrofluorobutane. The hydrofluoromethane is CH2F2 or CH3F. The fluoroolefin is CF2═CF2, ClFC═CF2, or CF3CF═CF2.
- -
-
Page/Page column 4
(2008/06/13)
-
- PROCESS FOR RECOVERING PENTAFLUOROETHANE, AND PRODUCTION METHOD OF PENTAFLUOROETHANE INVOLVING THE PROCESS
-
The process for recovering pentafluoroethane of the invention includes bringing a mixed gas containing pentafluoroethane and a non-condensable gas into contact with a chlorinated solvent, and allowing the chlorinated solvent to absorb pentafluoroethane contained in the mixed gas. The process for the production of pentafluoroethane of the invention uses the recovering process.
- -
-
Page/Page column 20-21
(2008/06/13)
-
- AZEOTROPE COMPOSITIONS COMPRISING NONAFLUOROPENTENE AND HYDROGEN FLUORIDE AND USES THEREOF
-
Disclosed herein are azeotrope compositions comprising 1,2,3,3,3-pentafluoropropene and hydrogen fluoride. The azeotrope compositions are useful in processes to produce and in processes to purify 1,2,3,3,3-pentafluoropropene. Additionally, disclosed herein are azeotrope and near-azeotrope compositions comprising 1,1,1,2,3,4,4,5,5,5-decafluoropentane and hydrogen fluoride.
- -
-
Page/Page column 21-22
(2008/06/13)
-
- Methane and methyl chloride as selective reducing agent in the transformation of hydrochlorofluorocarbons or chlorofluorocarbons to hydrofluorocarbons
-
A gas phase reaction process for producing a hydrofluorocarbon from a hydrochlorofluorocarbon or chlorofluorocarbon reactant by contacting, in the presence of a catalyst, the hydrochlorofluorocarbon or chlorofluorocarbon reactant with a reducing agent selected from methane, methyl chloride and mixtures thereof, to produce the hydrofluorocarbon.
- -
-
Page/Page column 6-7
(2008/06/13)
-
- Reactions of epoxides derived from internal perfluoroolefins with o-phenylenediamine and 2-aminophenol
-
The reactions of epoxy derivatives of internal perfluoroolefins with o-phenylenediamine and 2-aminophenol in dioxane gave 23-67% of the corresponding 2,3-bis(perfluoroalkyl)quinoxalines and 2,3-bis-(perfluoroalkyl)-2H-1,4- benzoxazin-2-ols, respectively. When N,N-dimethylacetamide was used as a solvent, the main reaction pathway was anionic isomerization of epoxides into ketones which were then converted into 2-perfluoroalkylbenzimidazoles (in the reactions with o-phenylenediamine) or 2-hydroxy-N-perfluoroalkanoylanilines (in the reactions with 2-aminophenol). The reaction of 3,4-epoxydodecafluorohexane with 2-aminophenol in N,N-dimethylacetamide was accompanied by unusual cyclization to afford 2-pentafluoropropanoyl-2-pentafluoroethyl-1,3- benzoxazolidine. Pleiades Publishing, Inc., 2006.
- Saloutina,Zapevalov,Saloutin,Kodess,Kirichenko,Pervova,Chupakhin
-
p. 558 - 566
(2007/10/03)
-
- Catalytic conversion of hydrofluoroalkanol to hydrofluoroalkene
-
Methane is used as the selective dehydrating agent for the production of 2,3,3,3-tetrafluoro-1-propene (R1234yf) from 2,2,3,3,3-pentafluoro-1-propanol. Supported transition metal catalysts are prepared and used for this reaction with high activity. Almost 58% selectivity to R1234yf is obtained at an alcohol conversion level of 60% using unsupported Ni-mesh as the catalyst. Pd and Pt show almost similar level of conversion; however, the selectivity to the desired product is low. The activity of the metal catalyst was found to be a function of the type of support material, activated carbon showing better activity than alumina. Different important process parameters such as temperature, pressure, and contact time are studied to optimize the process. High pressure and temperature are deleterious to the rate of 1234yf formation; yet, the highest yield to 1234yf is obtained while performing a reaction at 494° C. with a contact time of 23 sec.
- -
-
Page/Page column 3-4
(2008/06/13)
-
- Pentafluoroethane production method
-
Process for the manufacture of pentafluoroethane, according to which tetrafluoroethylene is subjected to reaction with an organic nitrogenous base hydrofluoride at a temperature of greater than 100° C. and not exceeding 160° C.
- -
-
Page/Page column 3
(2008/06/13)
-
- Method for the preparation of high surface area metal fluorides
-
The present invention is related to a method for preparing an amorphous metal fluoride of the formula MX+FX-δ comprising the steps of a) providing a precursor, whereby the precursor comprises a structure having a formula of Mx+F(x-δ)-yBy; and b) reacting the precursor with a fluorinating agent generating the amorphous metal flouride having a formula of Mx+Fx-δ, whereby M is selected from the group comprising metals of the second, third and fourth main group and any subgroup of the periodic table, B is a coordinately bound group; x is any integer of 2 or 3; y is any integer between 1 and 3; δ is 0 to 0.1; and x?δ>y.
- -
-
Page/Page column 8
(2010/10/20)
-
- Perfluoroalkanoic hydroformed mono-, bis (perfluorolefin alkyl) acid synthesis of salt and perfluorolefin alkylphosphonic
-
The present invention relates to a process for the preparation of monohydroperfluoroalkanes, bis(perfluoroalkyl)phosphinates and perfluoroalkylphosphonates which comprises at least the treatment of at least one perfluoroalkylphosphorane with at least one base in a suitable reaction medium.
- -
-
Page/Page column 16-17
(2008/06/13)
-
- PROCESS FOR PRODUCTION OF 1,1,1,2-TETRAFLUOROETHANE AND/OR PENTAFLUOROETHANE AND APPLICATIONS OF THE SAME
-
A process for producing high purity 1,1,1,2-tetrafluoroethane and/or pentafluoroethane by the step of purifying a crude product obtained by reacting trichloroethylene and/or tetrachloroethylene with hydrogen fluoride comprised of a main product including 1,1,1,2-tetrafluoroethane and/or pentafluoroethane, hydrogen fluoride as an azeotropic component with the main product, and impurity ingredients including at least an unsaturated compound, wherein said purifying step includes a step of bringing a mixture obtained by newly adding hydrogen fluoride into said crude product into contact with a fluorination catalyst in the vapor phase to reducing the content of the unsaturated compound contained in said crude product and a distillation step.
- -
-
Page/Page column 11; 16
(2008/06/13)
-
- Hydrofluorination catalyst and method
-
Hydrofluorination catalyst based on a chromium oxide which is poor in ammonium salts.
- -
-
Page column 5
(2008/06/13)
-
- Production and use of hexafluoroethane
-
A process for production of high-purity hexafluoroethane, wherein a mixed gas containing hexafluoroethane and chlorotrifluoromethane is reacted with hydrogen fluoride in a gas phase in the presence of a fluorination catalyst at 200-450° C., for fluorination of the chlorotrifluoromethane, or wherein pentafluoroethane containing chlorine compounds with 1-3 carbon atoms is reacted with hydrogen in a gas phase in the presence of a hydrogenation catalyst at 150-400° C., and the product is then reacted with fluorine in a gas phase in the presence of a diluent gas.
- -
-
-
- PROCESS FOR THE PREPARATION OF 1,1,1,2,2-PENTAFLUOROETHANE
-
A process for the preparation of pentafluoroethane is disclosed which involves contacting a mixture comprising hydrogen fluoride and at least one one starting material selected from haloethanes of the formula CX3191CHX2 and haloethenes of the formula CX2=CX2, where each X is independently selected from the group consisting of F and Cl (provided that no more than four of X are F), with a fluorination catalyst in a reaction zone to produce a product mixture comprising HF, HCl, pentafluoroethane, underfluorinated halogenated hydrocarbon intermediates and less than 0.2 mole percent chloropentafluoroethane based on the total moles of halogenated hydrocarbons in the product mixture. The process is characterized by the fluorination catalyst comprising (i) a crystalline cobalt-substituted alpha-chromium oxide where from about 0.05 atom % to about 6 atom % of the chromium atoms in the alpha-chromium oxide lattice are replaced by trivalent cobalt (Co+3) and/or (ii) a fluorinated crystalline oxide of (i).
- -
-
-
- PROCESS FOR PURIFYING PENTAFLUOROETHANE, PROCESS FOR PRODUCING THE SAME, AND USE THEREOF
-
ABSTRACT A process comprising bringing crude pentafluoroethane containing at least one compound selected from the group consisting of hydrofluorocarbons containing one carbon atom, hydrochlorofluorocarbons containing one carbon atom and hydrochlorocarbons containing one carbon atom, into contact with an adsorbent comprising a zeolite having an average pore size of 3 to 6 ? and a silica/aluminum ratio of 2.0 or less and/or a carbonaceous adsorbent having an average pore size of 3.5 to 6 ?, to reduce the content of the compound. The purified gas can be used as a low temperature refrigerant or an etching gas.
- -
-
-
- Processes for the purification and use of 2-chloro-1,1,1,2,3,3,3-heptafluoropropane and zeotropes thereof with HF
-
A process is disclosed for the separation of a mixture of HF and CF3CClFCF3. The process involves placing the mixture in a separation zone at a temperature of from about ?30° C. to about 100° C. and at a pressure sufficient to maintain the mixture in the liquid phase, whereby an organic-enriched phase comprising less than 50 mole percent HF is formed as the bottom layer and an HF-enriched phase comprising more than 90 mole percent HF is formed as the top layer. The organic-enriched phase can be withdrawn from the bottom of the separation zone and subjected to distillation in a distillation column to recover essentially pure CF3CClFCF3. The distillate comprising HF and CF3CClFCF3can be removed from the top of the distillation column while essentially pure CF3CClFCF3can be recovered from the bottom of the distillation column. The HF-enriched phase can be withdrawn from the top of the separation zone and subjected to distillation in a distillation column. The distillate comprising HF and CF3CClFCF3can be removed from the top of the distillation column while essentially pure HF can be recovered from the bottom of the distillation column. If desired, the two distillates can be recycled to the separation zone. Also disclosed are compositions of hydrogen fluoride in combination with an effective amount of CF3CClFCF3to form an azeotrope or azeotrope-like composition with hydrogen fluoride. Included are compositions containing from about 38.4 to 47.9 mole percent CF3CClFCF3. Also disclosed are processes for producing 1,1,1,2,3,3,3-heptafluoro-propane. One process uses a mixture comprising HF and CF3CClFCF3and is characterized by preparing essentially pure CF3CClFCF3as indicated above, and reacting the CF3CClFCF3with hydrogen. Another process uses an azeotropic composition as described above, and reacts the CF3CClFCF3with hydrogen in the presence of HF. Also disclosed is a process for producing hexafluoropropene. This process is characterized by preparing essentially pure CF3CClFCF3as indicated above, and dehalogenating the CF3CClFCF3.
- -
-
Page column 7
(2008/06/13)
-
- Method for preparing a hydro(chloro)fluoroalkane and catalyst
-
Process for the preparation of a hydro(chloro)fluoroalkane according to which a halogenated precursor of the hydro(chloro)fluoroalkane is reacted with hydrogen fluoride in the presence of a catalyst comprising chromium (Cr) and at least one other metal selected from the group consisting of aluminium, barium, bismuth, calcium, cerium, copper, iron, magnesium, strontium, vanadium and zirconium.
- -
-
-
- The radiation chemistry of acyclic hydrofluoro and perhalogenated ether and hydrocarbon compounds
-
The radiolytic stability of some hydrofluoroethers and hydrofluorocarbons was investigated and compared with those of perfluoropolyethers (PFPEs) and the CCl2FCClF2 (CFC 113). The experimental results indicate that stability depends mainly on the relative abundance of hydrogen atoms in the molecule; however, a significant role is played also by the chemical structure (i.e. the relative positions of the hydrogen atoms in the molecule). As a result, molecules containing hydrogen atoms as -OCF2H chain ends show a higher stability compared with the other hydrofluoro compounds. Based on the analysis of the end products and on the nature of radicals detected by EPR, radiolysis mechanisms are proposed and discussed. Due to their high dipole moments the hydrofluoro compounds and CCl2FCClF2 degrade mainly through an ionic mechanism.
- Marchionni, Giuseppe,Guarda,Buttafava,Faucitano, Antonio
-
p. 153 - 162
(2007/10/03)
-
- Method for purifying tetrachloroethylene and process for producing hydrofluorocarbons
-
Tetrachloroethylene containing a stabilizer is contacted with a zeolite having an average pore size of 3.4 to 11 ? and/or a carbonaceous adsorbent having an average pore size of 3.4 to 11 ? in a liquid phase to obtain a high purity tetrachloroethylene. A halogenated alkene and/or a halogenated alkane are reacted with hydrogen fluoride in the presence of a fluorination catalyst to produce a first hydrofluorocarbon, a halogenated alkene and/or a halogenated alkane are reacted with hydrogen fluoride in the presence of a fluorination catalyst to produce a second hydrofluorocarbon, and the products are joined and then distilled to obtain the first and second hydrofluorocarbons.
- -
-
Page/Page column 7-10
(2008/06/13)
-
- Preparation of 1-X-2,2-Difluoroethenylxenon(II) Tetrafluoroborates [CF 2=CXXe][BF4]
-
The new type of alkenylxenon(II) salts [CF2=CXXe] [BF 4] (X = H, Cl, CF3) was prepared by reacting the corresponding alkenyldifluoroboranes CF2=CXBF2 with XeF2 in 1,1,1,3,3-pentafluoropropa
- Frohn, Hermann-Josef,Bardin, Vadim V.
-
p. 2465 - 2469
(2008/10/09)
-
- An evaluation of the kinetic data for hydrogen abstraction from germanes in the gas phase by CF3 and C2F5 radicals
-
After the review of kinetic data for reaction of hydrogen abstraction from germanoorganic compounds by trifluoromethyl and pentafluoroethyl radicals in the gas phase it was possible to determine the relative kinetic reactivity of the two radicals under consideration. The contributing factors are the thermochemical effects of the investigated reactions, steric hindrance derived mainly from the size of substrate molecules and the polar interaction between the polarized germane molecules and the radicals of different electrophilicity. The polar effects occurring in these radical reactions contribute primarily to the activation energy, but they have no significant contribution to the pre-exponential factor.
- Pieniazek
-
p. 1739 - 1746
(2007/10/03)
-
- A study of trichloroethylene hydrofluorination using a kinetic model
-
The kinetic features of catalytic hydrofluorination of trichloroethylene and 2-chloro-1,1,1-trifluoroethane on chromium fluoride/magnesium fluoride catalyst were studied. The effect of pressure and addition of various components of the reaction mixture at the reactor inlet was studied using the developed model.
- Dmitriev,Trukshin,Smykalov
-
p. 771 - 776
(2007/10/03)
-
- Process for producing 1,1,1,2,2-pentafluoroethane
-
A process for producing 1,1,1,2,2-pentafluoroethane by fluorinating with hydrogen fluoride at least one of 2,2-dichloro-1,1,1-trifluoroethane and 2-chloro-1,1,1,2-tetrafluoroethane as a starting material, the process being characterized by separating the reaction mixture resulting from the fluorination into a product portion A mainly containing 1,1,1,2,2-pentafluoroethane and a product portion B mainly containing 2,2-dichloro-1,1,1-trifluoroethane, 2-chloro-1,1,1,2-tetrafluoroethane and hydrogen fluoride, removing a fraction mainly containing 2,2-dichloro-1,1,1,2-tetrafluoroethane from the product portion B, and recycling the rest of the product portion B as part of feedstocks for fluorination. According to the process of the invention, the amount of CFC-115 contained in the target HFC-125 can be remarkably reduced through a simplified procedure.
- -
-
Page column 5-7
(2008/06/13)
-
- Perfluoroalkylsulfone reactions with nucleophiles
-
Perfluorodialkylsulfones were found to react readily with metal hydroxides in water or alcohol solution and with ammonia to form fluorinated sulfonic acid derivatives.
- Barrera, Michael D.,Cheburkov, Yuri,Lamanna, William M.
-
-
- Chloropentafluoroethane hydrodechlorination over tungsten carbides: Influence of surface stoichiometry
-
The relationship between the mode of activation and the catalytic properties of tungsten carbides was studied. Tungsten carbides were prepared by temperature-programmed reaction of WO3 with methane/hydrogen mixture and activated according to several thermal treatments by varying the temperature or the feed composition. The acid-base characteristic increased with the extent of decarburization of the surface. The surface properties of WC could be adjusted toward the formation of unsaturated compounds or alternatively toward hydrogenolysis compounds. However, the convergence observed in the temperature-programmed selectivity curves, whatever the initial C/W ratio, showed that the sample surfaces reach similar compositions by recarburization during reaction. Such acidic properties were involved in the dehydrohalogenation of chloropentafluoroethane responsible mainly for the formation of unsaturated compounds.
- Granger,Giraudon,Delannoy,Leclercq,Leclercq
-
p. 358 - 362
(2007/10/03)
-
- Enhanced Lewis acidity by aliovalent cation doping in metal fluorides
-
A model regarding the generation of acidity in binary metal fluorides has been proposed and its validity has been examined for several binary fluoride systems with the general compositions MF3/M′F3 and MF2/M′F3. In accordance with this hypothesis, the binary systems (CrF3/AlF3, CrF3/FeF3 and AlF3/VF3) do not show acidities larger than the sum of the acidities of the component fluorides. The hypothesis predicts the generation of Lewis acidity when MF2 is the major component (host) and generation of Bronsted acidity when MF3 acts as the host for the MF2/M′F3. The experimental results (surface acidity and catalytic activity) confirmed the predictions made from this hypothesis for binary combinations MgF2/M′F3 (M′ = Cr, Al, Fe, V). The application of this model is discussed in terms of other parameters: ionic radii and the fluoride affinity of the metal fluorides involved.
- Kemnitz, Erhard,Zhu,Adamczyk
-
p. 163 - 170
(2007/10/03)
-
- PRODUCTION OF HYDROFLUOROALKANES
-
A process for the production of a hydrofluoroalkane, particularly 1,1,1,2-tetrafluoroethane or pentafluoroethane, which comprises contacting a hydrochlorofluoroethane or a hydrochlorofluoroethene with hydrogen fluoride and a fluorination catalyst and recovering a hydrofluoroalkane from the resulting products, the hydrochlorofluoroethane having the formula CClXYCFHZ and the hydrochlorofluoroethene having the formula CClA-CFZ wherein X and Y are each independently chlorine or fluorine, Z is chlorine or hydrogen and A is chlorine or fluorine provided that where each of X and Y is fluorine then Z is hydrogen. A preferred embodiment of the process is the production of 1,1,1,2-tetrafluoroethane from the hydrochlorofluoroethene CCl2═CFH.
- -
-
-
- Turnover Rate, Reaction Order, and Elementary Steps for the Hydrodechlorination of Chlorofluorocarbon Compounds on Palladium Catalysts
-
The rates of hydrodechlorination catalyzed by Pd supported on carbon for four chlorofluorocarbons spanned a range of 7 orders of magnitude. The rates scaled up to the bond strength of the carbon-chlorine bond for the gas-phase reactant. This finding demonstrates that the rate-determining step involves the scission of the C-Cl bond and suggests, through Polanyi and linear free-energy relationships, that rates for other compounds can be estimated if the C-Cl bond strength is known. The reaction orders for the most abundant products are approximately first-order for the chlorine-containing compound, half-order in H2, and inverse first-order in HCl. The reaction steps consistent with these orders include a rate-determining step involving the adsorption of the chlorofluorocarbon to a single site (which could be a single surface palladium atom) and equilibrated steps between gas-phase H2, gas-phase HCl, and adsorbed hydrogen and chlorine atoms. The rates on the supported catalysts are comparable to the ones reported before on a Pd foil, indicating that the support does not play a role in the reaction. The product distribution is independent of conversion, implying that the various products are formed from a single visit of the reactant on the surface and not from readsorption of gas-phase products. The four compounds studied were chloropentafluoroethane (CF3-CF2Cl), 2-chloro-1,1,1,2-tetrafluoroethane (CF3-CFClH), 1,1-dichlorotetrafluoroethane (CF3-CFCl2), and 1,1,1-trichloro-2,2,2-trifluoroethane (CF3-CCl3).
- Thompson,Rioux,Chen,Ribeiro
-
p. 3067 - 3077
(2007/10/03)
-
- Syntheses and Properties of Pentafluoroethylcopper(I) and -copper(III) Compounds: CuC2F5 ? D, [Cu(C2F5)2]-, and (C2F5)2CuSC(S)N(C2H 5)
-
The reactions of Cd(C2F5)2 · D and Zn(C2F5)2 · D (D = 2 CH3CN, 2 DMF), respectively, with copper(I) halides in the presence of halides quantitatively yield the CuC2Fs
- Naumann, Dieter,Roy, Thomas,Caeners, Bernd,Hütten, Dirk,Tebbe, Karl-Friedrich,Gilles, Theo
-
p. 999 - 1003
(2008/10/08)
-