Abstract: The present invention relates to a method for producing high-purity 1,1,1,2,3,3-hexafluoropropane and a composition containing mainly 1,1,1,2,3,3-hexafluoropropane, suitable for use as a cleaning agent in the semiconductor industry.

Abstract: The present invention provides a method for separating HFC-245cb and (E)-HFO-1234ze having close boiling points, i.e., boiling points with only 1° C. difference, by extractive distillation from a composition containing the HFC-245cb and the (E)-HFO-1234ze. More specifically, the present invention is a method for separating HFC-245cb and (E)-HFO-1234ze from a composition containing the HFC-245cb and the (E)-HFO-1234ze, the method comprising subjecting the composition to extractive distillation using at least one extractant selected from the group consisting of halogenated hydrocarbons, halogenated unsaturated hydrocarbons, nitriles, ketones, carbonates, alcohols, hydrocarbons, esters and ethers.

Abstract: There is provided a method of producing HFO with which diluent gas is easily separated even at a low boiling point and which has excellent productivity. A method of producing HFO includes: converting HFC of the formula (1) into the HFO of the formula (2) to obtain a first gas composition containing the HFO and the fluorine-containing solvent, CR1R2X1CR3R4X2 (1), CR1R2?CR3R4 (2), where in the formulae, R1 to R3 are H or F, R4 is H, F, CH3, CH2F, CHF2 or CF3, the total number of fluorine atoms of R1 to R4 is one or more, and the total number of hydrogen atoms of R1 to R4 is one or more. One of X1 and X2 is H, and the other of X1 and X2 is F; and separating the fluorine-containing solvent from the first gas composition to obtain a second gas composition containing the HFO.

Abstract: The present invention relates to a process for preparation of olefins containing fluorine.

Abstract: The invention relates to the separation of a mixture comprising 2-chloro-1,1-difluoroethane (R142) and trans-dichloroethylene (TDCE) by extractive distillation and more particularly to a separation process wherein the TDCE is removed selectively by extractive distillation, thus leading to purified 2-chloro-1,1-difluoroethane.

Abstract: A method for precisely predicting phase equilibrium from existing phase equilibrium data on the basis of a wide range of phase equilibrium data including binary vapor-liquid equilibrium data; a method or apparatus for designing or controlling a component separator or a refiner using the prediction method; and a program for designing this design or control apparatus. Binary phase equilibrium measurement data is used to calculate an index of proximity ratio to critical points and infinite dilution pressure gradients. The obtained index is correlated with the infinite dilution pressure gradients to newly calculate infinite dilution activity coefficients from the respective index to infinite dilution pressure gradients correlations. The obtained infinite dilution activity coefficients values are used to predict phase equilibrium. Thus, the obtained values are used to design or control a component separator or a refiner, such as a distillation column.

Abstract: The present invention provides a method for purifying chlorinated hydrocarbon(s), comprising cooling a mixture containing hydrogen fluoride and at least one chlorinated hydrocarbon selected from the group consisting of 2-chloro-3,3,3-trifluoropropene, 2,3-dichloro-3,3-difluoropropene, 1,2,3-trichloro-1,1-difluoropropane, and 1,1,1,2,3-pentachloropropane to cause liquid-liquid separation of the mixture into an upper liquid phase having a high hydrogen fluoride concentration and a lower liquid phase having a high chlorinated hydrocarbon concentration, and a method for purifying a chlorinated hydrocarbon, comprising subjecting the lower liquid phase obtained by the liquid-liquid separation to a distillation operation. According to the present invention, a chlorinated hydrocarbon can be purified by separating and removing hydrogen fluoride from a chlorinated hydrocarbon-hydrogen fluoride mixture under simple and economically advantageous conditions.

Abstract: The invention relates to a process for separating monochloro-trifluoropropenes such as HCFC-1233 from azeotrope or azeotrope like combinations with HF. The process employs a cold, liquid phase separations and multiple azeotropic distillation trains.

Abstract: To provide a method for efficiently separating 2,3,3,3-tetrafluoropropene (HFO-1234yf) and chloromethane (R40) from a composition comprising HFO-1234yf and R40. An azeotrope-like composition comprising from 58 to 78 mol % of HFO-1234yf and from 22 to 42 mol % of R40, and a method for producing HFO-1234yf, which comprises steps of distilling an initial mixture containing HFO-1234yf in a content exceeding 63 mol % in the total amount of HFO-1234yf and R40, thereby to separate the initial mixture into a first fraction in which the content of HFO-1234yf in the total amount of HFO-1234yf and R40 is lower than the content of HFO-1234yf in the total amount of HFO-1234yf and R40 in the initial mixture, and a second fraction in which the content of HFO-1234yf in the total amount of HFO-1234yf and R40 is higher than the content of HFO-1234yf in the total amount of HFO-1234yf and R40 in the initial mixture, and then obtaining HFO-1234yf having a reduced R40 concentration, from the second fraction.

Abstract: Disclosed is a reactor and agitator useful in a high pressure process for making 1-chloro-3,3,3-trifluoropropene (1233zd) from the reaction of 1,1,1,3,3-pentachloropropane (240fa) and HF, wherein the agitator includes one or more of the following design improvements: (a) double mechanical seals with an inert barrier fluid or a single seal; (b) ceramics on the rotating faces of the seal; (c) ceramics on the static faces of seal; (d) wetted o-rings constructed of spring-energized Teflon and PTFE wedge or dynamic o-ring designs; and (e) wetted metal surfaces of the agitator constructed of a corrosion resistant alloy.

Abstract: The present invention provides processes for the production of HCFO-1233zd, 1-chloro-3,3,3-trifluoropropene, from the starting material, 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf). In a first process, HCFO-1233zd is produced by the isomerization of HCFO-1233xf. In a second process, HCFO-1233zd is produced in a two-step procedure which includes (i) dehydrochlorination of HCFO-1233xf into trifluoropropyne; and (ii) hydrochlorination of the trifluoropropyne into HCFO-1233zd.

Abstract: The present invention is directed to processes for the production of 1233zd from 240fa and HF, with or without a catalyst, at a commercial scale. The 240fa and HF are fed to a reactor operating at high pressure. The resulting product stream comprising 1233zd, HCl, HF, and other byproducts is treated to one or more purification techniques including phase separation and one or more distillations to provide purified 1233zd, which meets commercial product specifications, i.e., having a GC purity of 99.5% or greater.

Abstract: The instant invention relates to a process and method for manufacturing 2,3,3,3-tetrafluoropropene by dehydrohalogenating a reactant stream of 2-chloro-1,1,1,2-tetrafluoropropane that is substantially free from impurities, particularly halogenated propanes, propenes, and propynes.

Abstract: Disclosed is a process for producing 2-chloro-1,3,3,3-tetrafluoropropene (1224), including a first step of separating 2,3-dichloro-1,1,1,3-tetrafluoropropane 234da) into erythro form and threo form, and a second step of bringing the separated erythro form or threo form in contact with a base to obtain 2-chloro-1,3,3,3-tetrafluoropropene (1224). The first step is a step of separating 234da by distillation to achieve a separation into a fraction containing mainly erythro form and a fraction containing mainly threo form. In the second step, 1224 cis form is obtained from the erythro form, and 1224 trans form is obtained from the threo form. By this process, it is possible to selectively and efficiently produce cis form or trans form of 2-chloro-1,3,3,3-tetrafluoropropene (1224).

Abstract: A method for removing a contaminant from a hydrochlorofluoroolefin (such as trans-1,1,1-trifluoro-3-chloro-2-propene (1233zd(E))) includes extracting a chlorofluorocarbon (such as trichlorofluoromethane (R11)) from a mixture comprising the hydrochlorofluoroolefin and the chlorofluorocarbon using extractive distillation in the presence of an extractive solvent comprising a chlorinated compound to form a purified hydrochlorofluoroolefin. This separation method provides for removal of a contaminant, such as R11, from a hydrochlorofluoroolefin, such as 1232zd(E), which are not separable by conventional distillation methods. The method may employ a process utilizing two distillation columns, for example, a first extractive distillation column and a second solvent recovery column, which allows for recycle of the extractive solvent to the first extractive distillation column.

Abstract: A process for the manufacture of 1-chloro-3,3,3-trifluoropropene (HCFC-1233zd) at commercial scale from the reaction of HCC-240 and HF is disclosed. In one embodiment, HCC-240fa and HF are fed to a reactor operating at high pressure. Several different reactor designs useful in this process include; a stirred-tank reactor (batch and/or continuous flow); a plug flow reactor; a static mixer used as a reactor; at least one of the above reactors operating at high pressure; optionally combined with a distillation column running at a lower pressure; and combinations of the above; and/or with a distillation column. The resulting product stream consisting of 1233zd, HCl, HF, and other byproducts is partially condensed to recover HF by phase separation. The recovered HF phase is recycled to the reactor. The HCl is scrubbed from the vapor stream and recovered as an aqueous solution.

Abstract: The present invention provides a novel method for separating hexafluoropropylene oxide (HFPO) from hexafluoropropylene (HFP), which is capable of reducing the burden on the environment. A mixture including HFPO and HFP is subjected to an extractive distillation operation using, as a solvent, at least one of a fluorine-containing saturated compound represented by the general formula CnHaFb (wherein n, a and b are integers which satisfy: n=3 to 8, 0?a?2n+1, and 1?b?2n+2) thereby separating into a first fraction including HFPO and a second fraction including HFP and the solvent. At least one of 1-bromopropane and 2-bromopropane may be u as the solvent in place of the fluorine-containing saturated compound.

Abstract: A process for separating cis-1,1,1,4,4,4-hexafluoro-2-butene from a first mixture comprising cis-1,1,1,4,4,4-hexafluoro-2-butene and at least one chlorofluoroolefin is disclosed. The process involves the steps of contacting the mixture with at least one extractive agent, to form another mixture, distilling the mixture; and recovering cis-1,1,1,4,4,4-hexafluoro-2-butene substantially free of chlorofluoroolefin.

Abstract: The present invention provides a process for producing 2,3,3,3-tetrafluoropropene, comprising distilling a mixture of water and 2,3,3,3-tetrafluoropropene to separate the mixture into a first stream and a second stream, the first stream containing 2,3,3,3-tetrafluoropropene with a water content higher than the original mixture, and the second stream containing 2,3,3,3-tetrafluoropropene with a water content lower than the original mixture; and obtaining 2,3,3,3-tetrafluoropropene with a reduced water content from the second stream. The process of the invention can efficiently remove water from 2,3,3,3-tetrafluoropropene (HFO-1234yf).

Abstract: Provided are azeotropic and azeotrope-like compositions of trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)) and water. Such azeotropic and azeotrope-like compositions are useful in isolating trans-1,3,3,3-tetrafluoropropene from impurities during production. Azeotropes of the instant invention are similarly useful in final compositions or for the manufacture of final compositions, such as blowing agent, propellants, refrigerants, diluents for gaseous sterilization and the like.

Abstract: This invention relates to an improved radiosynthesis of [18F]fluoromethyl bromide, whereby the distillation step has been improved to remove higher amounts of the dibromomethane radiolabeling precursor.

Abstract: The present invention provides a method for purifying chlorinated hydrocarbon(s), comprising cooling a mixture containing hydrogen fluoride and at least one chlorinated hydrocarbon selected from the group consisting of 2-chloro-3,3,3-trifluoropropene, 2,3-dichloro-3,3-difluoropropene, 1,2,3-trichloro-1,1-difluoropropane, and 1,1,1,2,3-pentachloropropane to cause liquid-liquid separation of the mixture into an upper liquid phase having a high hydrogen fluoride concentration and a lower liquid phase having a high chlorinated hydrocarbon concentration, and a method for purifying a chlorinated hydrocarbon, comprising subjecting the lower liquid phase obtained by the liquid-liquid separation to a distillation operation. According to the present invention, a chlorinated hydrocarbon can be purified by separating and removing hydrogen fluoride from a chlorinated hydrocarbon-hydrogen fluoride mixture under simple and economically advantageous conditions.

Abstract: The invention relates to a process for separating monochloro-trifluoropropenes such as HCFC-1233 from azeotrope or azeotrope like combinations with HF. The process employs a cold, liquid phase separations and multiple azeotropic distillation trains.

Abstract: Disclosed herein are processes for separation of 2,3,3,3-tetrafluoropropene and hydrogen fluoride using azeotropic distillation. Additionally, disclosed are processes for separating mixtures of 2,3,3,3-tetrafluoropropene, hydrogen fluoride and 1,1,1,2,3-pentafluoropropane (HFC-245eb) and/or 1,1,1,2,2-pentafluoropropane (HFC-245cb) by azeotropic distillation.

Abstract: The present invention relates to a process for separating close-boiling and azeotropic components of mixtures, wherein said mixtures contain at least one hydrofluorocarbon compound, using at least one ionic liquid.

Abstract: Provided are azeotropic and azeotrope-like compositions of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and hydrogen fluoride (HF). Such azeotropic and azeotrope-like compositions are useful as intermediates in the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf).

Abstract: Disclosed are azeotropic and azeotrope-like mixtures of (Z)-1-chloro-3,3,3-trifluoropropene (1233zd(Z)) and hydrogen fluoride. Such compositions are useful as an intermediate in the production of 1233zd(Z). The latter compound 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.

Abstract: Disclosed is a method of purifying (Z)-1-chloro-3,3,3-trifluoropropene of the formula [1], comprising: distilling a mixture containing (Z)-1-chloro-3,3,3-trifluoropropene and 1-chloro-1,3,3,3-tetrafluoropropane (CF3CH2CHClF), wherein the distilling is performed by extractive distillation of the mixture in the coexistence of at least one kind of compound selected from the group consisting of halogenated hydrocarbons of the formula [2], halogenated unsaturated hydrocarbons, nitriles, ketones, carbonates, ethers, esters and alcohols as an extractant [Chem. 8] CFnCl3-nCHXCClFmH2-m??[2] where X represents a hydrogen atom (H), a fluorine atom (F) or a chlorine atom (Cl); n represents an integer of 0 to 3; and m represents an integer of 0 to 2.

Abstract: The present invention relates to an azeotropic or azeotrope-like mixture consisting essentially of 1,1,1,2,3,3-hexafluoropropane, hexafluoropropene and hydrogen fluoride.

Abstract: The invention provides a method for separating halocarbons. In particular, a method for separating 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) based on differences in melting points of these compounds. More particularly the invention pertains to a method for separating HCFC-244bb from HCFO-1233xf which are useful as intermediates in the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf).

Abstract: Disclosed are azeotropic and azeotrope-like mixtures of (Z)-1-chloro-3,3,3-trifluoropropene (1233zd(Z)) and hydrogen fluoride. Such compositions are useful as an intermediate in the production of 1233zd(Z). The latter compound 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.

Abstract: Provided are azeotropic and azeotrope-like compositions of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) and hydrogen fluoride (HF). Such azeotropic and azeotrope-like compositions are useful as intermediates in the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf).

Abstract: It is an object of the present invention to provide a process for producing 1,2,3,4 -tetrachlorohexafluorobutane industrially inexpensively and efficiently by utilizing expensive fluorine gas efficiently and to provide a process which is capable of stably producing 1,2,3,4 -tetrachlorohexafluorobutane and in which, by carrying out fluorination reaction at a low temperature, side reactions such as formation of a low-boiling substance due to cleavage of C—C bonds and formation of an excess fluoride are difficult to occur. The process for producing 1,2,3,4-tetrachlorohexafluorobutane of the present invention is characterized in that it includes feeding fluorine gas to 1,2,3,4-tetrachlorobutane using plural reactors in the presence of a solvent and in the absence of a catalyst to allow the 1,2,3,4-tetrachlorobutane and the fluorine gas to react with each other, wherein a part or all of unreacted fluorine gas discharged from one reactor is introduced into a reactor different from said one reactor.

Abstract: The present invention provides a process for producing 1,2,3,4-tetrachlorohexafluorobutane having a high purity at a low cost industrially and efficiently. The process for producing 1,2,3,4-tetrachlorohexafluorobutane according to the present invention comprises a step of allowing 1,2,3,4-tetrachlorobutane to react with a fluorine gas to prepare a reaction product containing 1,2,3,4-tetrachlorohexafluorobutane and hydrogen-containing compounds as an impurity, and a step of introducing the reaction product into single or plural distillation columns and distilling to separate the hydrogen-containing compounds from the reaction product and thereby preparing purified 1,2,3,4-tetrachlorohexafluorobutane wherein the at least one of distillation columns has a theoretical plate number of 15 or more.

Abstract: Disclosed herein are processes for the production of hydrofluoroolefins by dehydrofluorination. Also disclosed herein are processes for separation of hydrofluoroolefins from hydrofluorocarbons and from hydrogen fluoride.

Abstract: Halocarbons of the structure CF3CF2CH2X, wherein X is either F or Cl or mixtures thereof prepared by: contacting at least one 2-fluorochloropropane with hydrogen fluoride in a first fluorination step in the gas phase or liquid phase under substantially anhydrous conditions, in the absence of added catalyst to partially fluorinate said 2-fluorochloropropane; contacting said partially fluorinated 2-fluorochloropropane with at least the stoichiometric molar equivalent of hydrogen fluoride under substantially anhydrous conditions, in the presence of at least one fluorination catalyst in a second fluorination step; removing said reaction products from contact with said catalyst, and isolating a substantial yield of at least 1,1,1,2,2,3-hexafluoropropane or 1,1,1,2,2, penta-3-chloropropane, or mixtures thereof, respectively.

Abstract: The invention provides a technique enabling the separation and recovery of an unreacted fluoromonomer from an aqueous fluoropolymer dispersion obtained by emulsion polymerization, without using any extraction solvent, and enabling the prevention of a hydrolysis of —SO2F and a like sulfonic acid precursor functional group convertible to sulfonic acid group. Thus, the invention provides a recovering method fluoromonomer having a sulfonic acid precursor functional group convertible to a sulfonic acid group and remaining unreacted from an aqueous fluoropolymer dispersion obtained by emulsion polymerization of the fluoromonomer, wherein the unreacted fluoromonomer is recovered from the aqueous fluoropolymer dispersion by evaporation, wherein the aqueous fluoropolymer dispersion has an acidic pH.

Abstract: A process for separating cis-1,1,1,4,4,4-hexafluoro-2-butene from a first mixture comprising cis-1,1,1,4,4,4-hexafluoro-2-butene and at least one chlorofluoroolefin is disclosed. The process involves the steps of contacting said first mixture with at least one extractive agent, to form a second mixture, distilling said second mixture; and recovering cis-1,1,1,4,4,4-hexafluoro-2-butene substantially free of chlorofluoroolefin.

Abstract: A process for recovering hexafluoropropylene and hexafluoropropylene oxide from a liquid mixture of these components is provided. The process includes, in a stripping stage, contacting the mixture with a gaseous stripping agent, thereby to strip hexafluoropropylene from the mixture. A gaseous product comprising hexafluoropropylene and gaseous stripping agent is withdrawn from the stripping stage, as is a liquid product comprising hexafluoropropylene oxide.

Abstract: The production process for 1,2,3,4-tetrachlorohexafluorobutane of the present invention is characterized in that 1,2,3,4-tetrachlorobutane is reacted with fluorine in the presence of a solvent containing hydrogen fluoride. The 1,2,3,4-tetrachlorobutane may be obtained by chlorination of 3,4-dichlorobutene-1. Further, the present invention provides as well a process of refining 1,2,3,4-tetrachlorohexafluorobutane obtained in the manner described above. According to the present invention, 1,2,3,4-tetrachlorohexafluorobutane which is useful, for example, as a synthetic raw material for hexafluoro-1,3-butadiene used as an etching gas for semiconductors can industrially efficiently be produced by using 1,2,3,4-tetrachlorobutane which is a by-product of chloroprene and which has so far been disposed.

Abstract: The invention provides a method for separating halocarbons. In particular, a method for separating 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) based on differences in melting points of these compounds. More particularly the invention pertains to a method for separating HCFC-244bb from HCFO-1233xf which are useful as intermediates in the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf).

Abstract: The invention relates to a process for separating monochloro-trifluoropropenes such as HCFC-1233 from azeotrope or azeotrope like combinations with HF. The process employs a cold, liquid phase separations and multiple azeotropic distillation trains.

Abstract: An apparatus and process for the separation of refrigerant mixtures is provided. The apparatus includes a first distillation column, a first condenser, and a first collection vessel. The apparatus also includes a sorter vessel that includes a sorter agent, wherein the sorter vessel is fluidly connected to the first distillation column.

Abstract: The present invention relates to an azeotropic or azeotrope-like mixture consisting essentially of 1,1,1,2,3,3-hexafluoropropane, hexafluoropropene and hydrogen fluoride.

Abstract: Provided are azeotropic and azeotrope-like compositions of 1,2,3,3,3-pentafluoropropene (HFO-1225ye) and water. Such azeotropic and azeotrope-like compositions are useful in isolating 1,2,3,3,3-pentafluoropropene from impurities during production. Azeotropes of the instant invention are similarly useful in final compositions or manufacturing final compositions, such as blowing agent, propellants, refrigerants, diluents for gaseous sterilization and the like.

Abstract: Disclosed is a method of purifying (Z)-1-chloro-3,3,3-trifluoropropene of the formula [1], comprising: distilling a mixture containing (Z)-1-chloro-3,3,3-trifluoropropene and 1-chloro-1,3,3,3-tetrafluoropropane (CF3CH2CHClF), wherein the distilling is performed by extractive distillation of the mixture in the coexistence of at least one kind of compound selected from the group consisting of halogenated hydrocarbons of the formula [2], halogenated unsaturated hydrocarbons, nitriles, ketones, carbonates, ethers, esters and alcohols as an extractant [Chem. 8] CFnCl3-nCHXCClFmH2-m??[2] where X represents a hydrogen atom (H), a fluorine atom (F) or a chlorine atom (Cl); n represents an integer of 0 to 3; and m represents an integer of 0 to 2.

Abstract: Halocarbons of the structure CF3CF2CH2X, wherein X is either F or Cl or mixtures thereof prepared by: contacting at least one 2-fluorochloropropane with hydrogen fluoride in a first fluorination step in the gas phase or liquid phase under substantially anhydrous conditions, in the absence of added catalyst to partially fluorinate said 2-fluorochloropropane; contacting said partially fluorinated 2-fluorochloropropane with at least the stoichiometric molar equivalent of hydrogen fluoride under substantially anhydrous conditions, in the presence of at least one fluorination catalyst in a second fluorination step; removing said reaction products from contact with said catalyst, and isolating a substantial yield of at least 1,1,1,2,2,3-hexafluoropropane or 1,1,1,2,2, penta-3-chloropropane, or mixtures thereof, respectively.

Abstract: Disclosed herein are azeotrope and near-azeotrope compositions comprising E-1,1,1,2,3-pentafluoropropene (E-HFC-1225ye) and hydrogen fluoride. The azeotrope and near-azeotrope compositions are useful in processes to produce and in processes to purify E-HFC-1225ye and/or Z-1,1,1,2,3-pentafluoropropene (Z-HFC-1225ye). Also disclosed are processes for the extractive distillation to separate E-HFC-1225ye from Z-HFC-1225ye.

Abstract: 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.

Abstract: A method of producing a fluoropropane fluoropropene of formula CF3CH?CHF, comprising contacting a mixture of 1,1,1,3,3-pentafluoropropane and Z-1,3,3,3-tetrafluoropropene in the gas phase with a catalyst comprising at least one catalyst selected from the group consisting of fluorinated Cr2O3 or Cr/Ni on fluoride alumina, in the presence of an oxygen containing gas, to form a mixture comprising Z-1,3,3,3-tetrafluoropropane Z-1,3,3,3-tetrafluoropropene, E-1,3,3,3,-tetrafluoropropene, hydrogen fluoride, and optionally unreacted 1,1,1,3,3-pentafluoropropane, separating the E-1,3,3,3-tetrafluoropropene from the Z-isomer and any unreacted 1,1,1,3,3-pentafluoropropane, if present, and recovering said E-1,3,3,3-tetrafluoropropene.