US20020032356A1 - Synthesis of perfluoroolefins - Google Patents
Synthesis of perfluoroolefins Download PDFInfo
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- US20020032356A1 US20020032356A1 US09/878,540 US87854001A US2002032356A1 US 20020032356 A1 US20020032356 A1 US 20020032356A1 US 87854001 A US87854001 A US 87854001A US 2002032356 A1 US2002032356 A1 US 2002032356A1
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/26—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton
- C07C17/263—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton by condensation reactions
- C07C17/269—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton by condensation reactions of only halogenated hydrocarbons
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0053—Details of the reactor
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/02—Apparatus characterised by being constructed of material selected for its chemically-resistant properties
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/361—Preparation of halogenated hydrocarbons by reactions involving a decrease in the number of carbon atoms
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00049—Controlling or regulating processes
- B01J2219/00051—Controlling the temperature
- B01J2219/00054—Controlling or regulating the heat exchange system
- B01J2219/00056—Controlling or regulating the heat exchange system involving measured parameters
- B01J2219/00058—Temperature measurement
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00049—Controlling or regulating processes
- B01J2219/00051—Controlling the temperature
- B01J2219/00121—Controlling the temperature by direct heating or cooling
- B01J2219/00123—Controlling the temperature by direct heating or cooling adding a temperature modifying medium to the reactants
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00049—Controlling or regulating processes
- B01J2219/00051—Controlling the temperature
- B01J2219/00132—Controlling the temperature using electric heating or cooling elements
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00049—Controlling or regulating processes
- B01J2219/00051—Controlling the temperature
- B01J2219/00159—Controlling the temperature controlling multiple zones along the direction of flow, e.g. pre-heating and after-cooling
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00049—Controlling or regulating processes
- B01J2219/00164—Controlling or regulating processes controlling the flow
- B01J2219/00166—Controlling or regulating processes controlling the flow controlling the residence time inside the reactor vessel
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/02—Apparatus characterised by their chemically-resistant properties
- B01J2219/0204—Apparatus characterised by their chemically-resistant properties comprising coatings on the surfaces in direct contact with the reactive components
- B01J2219/0236—Metal based
Definitions
- This invention relates to the synthesis of perfluoroolefins, including tetrafluoroethylene and hexafluoropropylene by pyrolysis of fluorinated compounds.
- TFE Tetrafluoroethylene
- HFP hexafluoropropylene
- CFC-22 CHClF 2
- Hexafluoropropylene is commercially prepared by pyrolyzing TFE (U.S. Pat. No. 2,758,138).
- TFE and HFP are prepared sequentially.
- HFP is disclosed in other patents as being preparable by pyrolysis of a wide variety of fluorocarbons, e.g.
- TFE and HFP are reported to be preparable simultaneously, i.e. co-synthesized, by pyrolyzing a) chlorodifluoromethane to a mixture of TFE and HFP (U.S. Pat. No.
- U.S. Pat. No. 5,334,783 discloses a process for the preparation of hexafluoropropylene by thermal cleavage which uses a mixture (e.g., an azeotropic mixture) of chlorotetrafluoroethane and perfluorocyclobutane.
- a mixture e.g., an azeotropic mixture
- Various reactor wall materials are mentioned including “platinum or similar noble metals”.
- the use of a platinum-tube reactor is exemplified. This patent suggests that where mixtures of chlorotetrafluoroethane isomers are employed, the ratio of CHClFCF 3 to CHF 2 CClF 2 is preferably not more than 1:4.
- the present invention provides a pyrolysis process for the co-synthesis of tetrafluoroethylene, hexafluoropropylene, and other fluoromonomers that solves these problems, i.e. providing the economic advantage of simultaneous production of HFP and TFE, and either reducing or eliminating both a) plugging of the pyrolysis reactor and b) the formation primarily of PFIB and CF 2 ⁇ CFCl and other by-products. It has been discovered that the selection of gold as a component of at least the reaction zone of the pyrolysis reactor provides this result.
- the present invention is a reactor for the pyrolysis of reactants that can produce fluoromonomers, said reactor comprising a reaction zone, the surface of which reaction zone comprises gold.
- the present invention is a reactor for the pyrolysis of reactants that can produce fluoromonomers, said reactor comprising a reaction zone and a quench zone, the surfaces of which comprise gold.
- a third embodiment of this invention is a process comprising feeding at least one reactant which can produce fluoromonomers into a reactor having a reaction zone, the surface of which reaction zone comprises gold, under conditions sufficient to produce fluoromonomers, including tetrafluoroethylene and hexafluoropropylene.
- the present invention is a process for the pyrolysis of reactants that can produce fluoromonomers, such as TFE and HFP, wherein the reactant is at least one compound selected from the group consisting of compounds that can provide a CF 2 : moiety, a CF 3 CF: moiety, and a CF 2 CF 2 : moiety.
- the unsatisfied valences of these moieties are shown as at the end of the moiety.
- This representation is similar to that used for divalent carbon moieties known as carbenes. As used here, this representation does not exclude carbenes, and is not limited to carbenes.
- the present invention is a process for the pyrolysis of reactants that can produce fluoromonomers, such as TFE and HFP, wherein said reactants are a mixture of a monocarbon compound that can provide the CF 2 : moiety together with a) a dicarbon compound selected from the group consisting of compounds that can provide the CF 3 CF: moiety and the CF 2 CF 2 : moiety, and tetrafluoroethylene, and/or b) perfluorocyclobutane.
- reactants are a mixture of a monocarbon compound that can provide the CF 2 : moiety together with a) a dicarbon compound selected from the group consisting of compounds that can provide the CF 3 CF: moiety and the CF 2 CF 2 : moiety, and tetrafluoroethylene, and/or b) perfluorocyclobutane.
- a sixth embodiment of this invention is a process for producing at least one fluoroolefin selected from the group consisting of tetrafluoroethylene and hexafluoropropylene, comprising: pyrolyzing a gaseous feed containing C 2 HClF 4 and perfluorocyclobutane at a temperature of from about 600° C. to about 1000° C. in a reactor wherein surfaces exposed to said pyrolysis are gold; wherein a molar ratio of C 2 HClF 4 to perfluorocyclobutane in said feed is from about 1:10 to about 10:1, and a molar ratio of CHClFCF 3 to CHF 2 CClF 2 in said feed is at least about 1:1.
- the temperature and residence time of the feed compound(s) are chosen such that the yield to TFE and HFP combined is preferably at least about 85%.
- Yield as used herein is the total number of carbon atoms in the products, divided by the total number of carbon atoms in the feed to the pyrolysis reactor.
- lectivity as used herein is the total number of carbon atoms in the products, divided by the total number of carbon atoms in that fraction of the feed that is converted by pyrolysis.
- products is meant the identified perfluoroolefins or other identified fluorinated organic compounds exclusive of the compounds fed to the reactor.
- fluoromonomer includes, but is not limited to TFE and HFP.
- Pyrolysis as the term is used herein, means chemical change produced by heating. However, it is not the intention of the inventors to speculate upon the mechanism of reactions that take place in pyrolysis. When more than one reactant is present during pyrolysis, only one may be changed by heat and the product or products of that change may react with one or more of the reactants. On the other hand, more than one of the reactants may change under heating before reacting further, if further reaction takes place.
- Pyrolysis reactors generally comprise three zones: a) a preheat zone, in which reactants are brought close to the reaction temperature; b) a reaction zone, in which reactants reach reaction temperature and are at least partially pyrolyzed, and products and any byproducts form; c) a quench zone, in which the stream exiting the reaction zone is cooled to stop the pyrolysis reaction.
- the present invention embodies the discovery that gold as a material of the surface in the reactor, contributes something more to the reaction than simply resistance to the reaction conditions and chemicals: The ability to reduce or eliminate both the formation of salts and of coke on the exposed reactor surface, as well as to reduce the production of PFIB and CF 2 ⁇ CFCl as described above and reduce formation of polymer in the quench zone.
- thermogravimetric analyzer TGA
- weight changes as a consequence of the gas phase pyrolysis reaction can be followed. While gold consistently shows little weight change during the reaction, Inconel® shows first weight decrease, consistent with corrosion to form volatile salts, and then a large weight increase, due to heavy coke build up.
- Post-reaction analysis shows a thick layer of coke deposit as well as evidence of sublimed metal chloride salts at the cool exit end of the TGA reactor. Details will be found in the Examples.
- Electrode refers to the surface that is exposed to the reactants and/or reaction products.
- the reactor can be of conventional design.
- the reactor can be tubular, wherein the pyrolysis reaction occurs in the interior of the tube, and the tube can have a variety of cross-sectional shapes, such as circular, oval (elliptical) or polygonal, said shapes being of the interior or of the exterior surfaces of the tube, or both.
- the tubular reactor will typically have an inner diameter in the case of circular cross-section of at least about 0.125 in (0.32 cm), preferably about 0.125 in (0.32 cm) to about 3 meters, more preferably about 0.5 in (1.27 cm) to about 2 m, and most preferably about 1 in (2.54 cm) to about 1 m.
- the gold on the interior surface of the reaction zone can form the entire thickness of the reactor wall, but for economy need only be a lining supported by a heat-resistant, thermally conductive material of construction, such as a metal which has a melting temperature of at least about 1100° C. and which gives structural integrity to the reactor.
- Inconel® and Hastelloy® are nickel alloys suitable for use as supporting materials for the gold lining of the reactors of the invention described herein (see for example U.S. Pat. No. 5,516,947).
- Other thermally conductive supporting materials can be used. Thermal conductivity enables the reactor to be externally heated to provide the interior temperature necessary for the pyrolysis reaction. It is desirable that the supporting material be metallurgically bonded to the gold lining for the best heat transfer.
- a metallurgical bond is meant a bond in which atoms of the metals in the supporting material and the gold lining interdiffuse, that is, diffuse among each other about the bonded interface.
- a heating medium will be flowed between the interior wall of the shell and the exterior walls of the tubular reactors bundled therein to provide the heating for the pyrolysis reaction.
- the shell can be exteriorly heated or fired by means such as electrical means to provide the interior heating.
- the combination of the shell and the tubular reactors positioned therein forms the pyrolysis furnace.
- the reactor may consist of a single reaction vessel, where the required heat for the reaction is other means such as hot inert gas mixed with the reactants. Use of hot inert gas to supply some or all of the heat needed for the reaction reduces or eliminates the heat that must be supplied through the reactor wall.
- the thickness of the gold lining is a factor in the useful life of the reactor. Deterioration of the lining is an effect of pyrolysis conditions, cleaning operations, and the diffusion of metal from the supporting material into the gold. Cleaning operations abrade the surface, resulting in loss of gold. Diffusion will eventually bring the atoms of the backing material to the surface of the reaction zone. The presence of some quantity of metals other than gold can be tolerated at the reaction surface, but when this occurs to a sufficient extent, unwanted side reactions and fouling reach the point at which replacement of the surface is necessary. The undesirable effects of cleaning and diffusion can be delayed by using a thicker gold lining, and the useful life of the reactor will thereby be greater, though the initial investment cost will also be greater. Typical gold lining thicknesses will be about 10 to about 100 mils (0.25 to 2.5 mm).
- the pyrolysis reactor may be completely gold-lined, or may have unlined sections in the preheat zone, upstream of the gold-lined reaction zone of the reactor, and in the quench zone, downsteam of the gold-lined reaction zone.
- the preheat zone is used to preheat the gaseous reactant feed mixture and the quench zone is used for quenching the gaseous reaction mixture to a temperature less than about 500° C. to minimize coke and/or polymer formation downstream of the reaction zone. Quenching may be accomplished by interior cooling or exterior cooling, or both.
- Reactants that can produce fluoromonomers under the conditions of this invention are suitable feed materials.
- feed materials Preferable are mixtures of feed reactants providing both the CF 2 : and the CF 3 CF: or CF 2 CF 2 : moieties in the reactor that comprise a monocarbon compound and a) a dicarbon compound that in addition to atom, or b) tetrafluoroethylene, or c) perfluorocyclobutane.
- the mixture can include chlorodifluoromethane (CF 2 HCl) (HCFC-22), and/or CF 3 H (HFC-23) to provide the CF 2 : moiety upon pyrolysis in the reactor, and CF 3 CF 2 H (HCFC-125), or CF 2 ⁇ CF 2 , perfluorocyclobutane (c-318), and chlorotetrafluoroethane to provide the CF 3 CF: and/or CF 2 CF 2 : moieties.
- the chlorotetrafluoroethane can include CHFClCF 3 (HCFC-124) and CF 2 ClCF 2 H (HCFC-124a).
- HCFC-124 is preferably the major component of the dicarbon reactant, disregarding compounds that are used as inert gases and that do not undergo significant conversion in the reactor.
- major it is meant that the mole ratio of HCFC-124:HCFC-124a is greater than about 1:1, preferably greater than about 3:2, more preferably greater than about 7:3, and most preferably greater than about 4:1.
- the proportion of CF 2 : providing compound to CF 3 CF: or CF 2 CF 2 : providing compound will preferably be about 1:5 to about 5:1 on a molar basis and more preferably 1:1.
- HFC-22 and/or HFC-23 with HCFC-124 and HCFC-124a Preferred monocarbon and dicarbon compound feeds to the reactor are HCFC-22 and/or HFC-23 with HCFC-124 and HCFC-124a.
- HFC-23 may be used as a recycle gas in the reactor system. In this case, HFC-23 may be the major component in the reactor.
- Other reactants useful under the conditions of this invention include mixtures of chlorotetrafluoroethane and perfluorocyclobutane.
- the molar ratio of chlorotetrafluoroethane:perfluorocyclobutane is from about 1:10 to 10:1, preferably from about 1:3 to about 3:1.
- the preferred mole ratios of HCFC-124:HCFC-124a are as stated above.
- Azeotrope or azeotrope-like mixtures of chlorotetrafluoroethane and perfluorocyclobutane as well as azeotrope or azeotrope-like mixtures of CHClFCF 3 with HF and/or HCl, and azeotrope or azeotrope-like mixtures of perfluorocyclobutane with HF and/or HCl can be used as at least a portion of the reactant feed.
- These azeotropes or azeotrope-like mixtures can be obtained, for example, as by-products from the tetrafluoroethylene manufacturing process by the thermal cleavage of chlorodifluoromethane.
- Chlorotetrafluoroethane alone may be used in the synthesis of TFE, HFP, and perfluorocyclobutane.
- the mole ratio of HCFC-124a:HCFC-124 is at least about 9:1 and is preferably about 19:1.
- Perfluorocyclobutane (c-318) may also be used with CHF 2 Cl (HCFC-22) to make TFE and HFP.
- the mole ratio of HCFC-22:c-318 is from about 9:1 to about 1:1, preferably from about 7:1 to about 1:1, most preferably from about 7:1 to about 5:3.
- the effect of gold lining on the pyrolysis reaction is profound in the sense that it increases the selectivity of the reaction to form useful fluoroolefin products, notably TFE and HFP, with much-reduced formation of salts, coke, or polymer, or undesirable by-products such as PFIB or CFC-1113.
- the process is especially useful for making a mixture of TFE and HFP in which the TFE is at least about 30 mole %, but the process can make TFE/HFP reaction products in which the TFE content is at least about 50 mole % and preferably at least about 60 mole %. Generally, at least about 5 mole % of HFP will be present in the combined amount of TFE and HFP formed.
- the residence time in the reaction zone is less than one second, and more preferably the residence time is about 0.01 to about 0.5 seconds and even more preferably, from about 0.05 to about 0.2 seconds.
- Residence time is determined from the net volume of the reaction zone and the volume feed rate of the gaseous feed to the reactor at reaction temperature and pressure and refers to the amount of time a given volume of gas (containing starting materials and reaction products) remains in the reactor.
- the volume of the tube forming the reaction zone is the volume of that part of the tube that is lined with gold minus any volume used as a quench zone. As the residence time is increased from these reaction times, the formation of coke, salts, and/or polymer and undesirable by-products increases.
- British Patent 1,062,768 discloses that at least 10 wt % of CFC-1113 is formed, based on the weight of the HFP formed, when residence times range from 0.75 to 3 seconds (Table on page 3) and that a residence time of 1 to 3 seconds is preferred (page 2, line 66).
- the present invention produces less than about 3 wt % of CFC-1113 based on the weight of HFP formed, and it is possible to operate the process of the present invention to produce less than about 0.01 wt %, CFC-1113, based on HFP.
- the feed gas mixture of reactants which is at atmospheric pressure, is preheated to a temperature approaching but not at the temperature at which pyrolysis begins.
- Higher gas temperatures increase the formation of undesirable by-products and coke and/or polymer formation. So does higher wall temperature.
- the wall temperature may be lower that the gas temperature. Selectivity to useful fluoroolefins like HFP and TFE will be increased.
- the gas temperature within the reaction zone is considered to be the pyrolysis reaction temperature and is measured using a thermocouple in the gas phase in the reaction zone.
- the reaction zone is heated to a temperature sufficient for the pyrolysis reaction to occur, preferably within the reaction time of less than one second.
- the walls will be heated to a temperature higher than the gaseous reactant mixture, by only about 100° C., preferably by only about 50C higher, and more preferably by only about 25° C., sufficiently to maximize the formation of TFE and HFP, but not so high as to negatively impact the selectivity of TFE and HFP, and increase the formation of PFIB and that of miscellaneous by-products as well as the formation of any appreciable amount of coke on the interior surface of the reaction zone and polymer in the quench zone and beyond that point in the system. It has been found that reactor temperatures of about 600° C.
- the combination of residence time and temperature of the gaseous reaction mixture in the reaction zone is selected to be effective in producing a selectivity of useful fluoroolefin products like HFP and TFE of at least about 85% with the total amount of PFIB and/or CFC-1113 being less than about 5 wt %, based on the combined weight of TFE and HFP produced. More preferably, the amount of these undesired by-products is less than about 1 and about 3 wt % respectively, based on combined TFE plus HFP production and most preferably, based on the weight of HFP produced.
- the yield loss attributable to coke and polymer formation is preferably no greater than 1 wt % based on TFE and HPF produced, whereby the process can be conducted for long periods of time without furnace shut-down for reactor clean out.
- the gaseous feed mixture to the furnace includes an inert gas along with the reactant mixture, which inert gas is free of oxygen.
- inert gas can be used to supply heat to the reaction. This is especially useful for reactors of large cross-sectional area. These, if heated solely through the walls, would require excessively high wall temperatures and this would promote undesirable reactions and fouling.
- inert gases which do not decrease the desired products are helium, nitrogen, hydrofluorocarbons, or perfluorocarbons that are compatible with the reaction.
- a compatible inert gas is one that is sufficiently stable under reaction conditions, that is, does not undergo significant self- or synergistic decomposition or reaction at about atmospheric pressure and about 850° C.
- CF 4 is an example of a compatible inert gas of the perfluorocarbon type. Decomposition of less than about 5% is tolerable in an inert gas if the decomposition products do not adversely affect the desired cosynthesis of TFE and HFP.
- the inert gas can be incorporated into the gaseous mixture of reactants by addition thereto after the mixture is formed or by addition to one of the reactants prior to combination with the other reactant or reactants.
- the flow of the feed through the reactor is partially obstructed to cause back-mixing, i.e. turbulence, and thereby promote mixing of reactants and good heat transfer, further reducing the necessary residence time of the feed in the reactor, e.g. to less than about one-half second.
- This partial obstruction can be conveniently obtained by placing packing within the interior of the reactor, filling its entire cross-section or by using perforated baffles.
- the reactor packing can be particulate or fibrillar, preferably in cartridge disposition for ease of insertion and removal from the furnace, has an open structure like that of Raschig Rings or other packings with a high free volume, to avoid the accumulation of coke and to minimize pressure drop, and permits the free flow of gas, while nevertheless causing back-mixing of the gas.
- the free volume is the volume of the reaction zone minus the volume of the material that makes up the reactor packing.
- the free volume is at least about 80%, preferably at least about 90%, and more preferably about 95%.
- the reactor packing is composed of a material such as quartz, silicon carbide, aluminum trifluoride, or fluorided alumina.
- the fluorided alumina can be obtained by treating a suitable alumina, such as gamma alumina or a high density alpha alumina, with a fluoriding agent such as HF, CHF 3 , or CH 2 F 2 to provide a high concentration of fluoride, i.e. of greater than about 90% on the surface.
- a fluoriding agent such as HF, CHF 3 , or CH 2 F 2
- One procedure for fluoriding alumina is to place the packing in a stream of CH 2 F 2 , and heat it to about 700° C. for about 4 hours. After flushing the packing with nitrogen, it is heated in air at about 600° C. for about 4 hours to remove carbon deposits.
- Nano-size particles (defined herein as being about 1 to about 100 nm in diameter) of gold may be loaded onto the alpha alumina packing, for additional improved conversion and improved selectivity of HFP and TFE relative to the case of adding only fluorided packing. Such loading is preferably done after the above-mentioned fluoriding is completed.
- the coating method is described in the Example Section.
- Increased back-mixing can also be accomplished by increasing the feed rate so as to cause turbulent flow through the reactor.
- the process of the present invention is usually carried out wherein the conversion per pass (average of the monocarbon and dicarbon compound feeds) is equivalent to about 20% to about 80% to obtain optimum yield of TFE and HFP.
- the respective reactants are preheated either as a mixture or separately.
- the preheat temperature should be as high as possible without causing pyrolysis. That is, less than about 1% of the reactant or reactants should be pyrolyzed during the time the reactant is at the preheat temperature.
- the preheat temperature depends upon the reactant, and in mixtures, upon the combination of reactants. For instance, it has been established by experiment that in the gold-lined TGA reactor (described in the Example Section as Reactor #1) that CHF 2 Cl begins to decompose at about 430° C.
- reaction zone wall temperature can be reduced.
- TFE and HFP produced are recovered and refined by techniques known to the art and the useful by-products such as HCFC-124a and perfluorocyclobutane are recycled back to the reactor to produce additional amounts of the monocarbon and dicarbon intermediates under the reaction conditions employed.
- TFE Polymerizations of TFE are well known (see e.g., U.S. Pat. No. 2,230,654 and U.S. Pat. No. 2,394,243).
- the production of TFE as described herein can be used as an important aspect of such polymerizations.
- polymerizations of TFE when subjected to super-atmospheric pressure particularly when a catalyst is present).
- Copolymerizations of TFE with other olefinic comomomers including in some embodiments HFP
- copolymerizations of HFP with other olefinic comonomers and copolymerizations of both TFE and HFP with other olefinic comonomers are each well known.
- the production of TFE and/or HFP as described herein can be used as an important aspect of such copolymerizations.
- TFE Polymerizations of TFE are well known (see e.g., U.S. Pat. No. 2,230,654 and U.S. Patent No. 2,394,243).
- the production of TFE as described herein can be used as an important aspect of such polymerizations.
- polymerizations of TFE when subjected to super-atmospheric pressure particularly when a catalyst is present).
- Copolymerizations of TFE with other olefinic comomomers including in some embodiments HFP
- copolymerizations of HFP with other olefinic comonomers and copolymerizations of both TFE and HFP with other olefinic comonomers are each well known.
- the production of TFE and/or HFP as described herein can be used as an important aspect of such copolymerizations.
- the HFP produced in the manner described herein may be copolymerized with various other olefinic compounds.
- Such polymerizations, especially such polymerizations catalyzed by free radical initiators are well known in the art (see e.g., H.
- Useful copolymers include those with repeat units derived from one or both of tetrafluoroethylene and vinylidene fluoride, and optionally other comonomers.
- the polymerizations may be carried out by any method known for the copolymerization of HFP.
- the copolymerization may be in an aqueous medium, an aqueous dispersion or emulsion, or may be carried out in supercritical CO 2 .
- the particular conditions used will depend on the polymerization method chosen, and may be conventional conditions for that method.
- the HFP may also be copolymerized according to the processes described in U.S. Pat. No. 5,478,905 and U.S. Pat. No. 5,637,663, both of which are hereby included by reference. When used in a polymerization the HFP is preferably purified to a purity typical of HFP used as a monomer.
- the resulting polymers may be thermoplastics useful as molding resins, or elastomers useful in seals. In both cases the HFP-containing polymers often have good solvent, chemical and/or high temperature properties.
- Reactor #1 is a modified TA Instruments (New Castle Delaware USA) thermogravimetric analyzer (TGA) mounted horizontally and consisting of a 1 inch (2.5 cm) diameter quartz tube inside a temperature programmable computer controlled furnace. Running down the center of this tube is a quartz rod which is attached to a sensitive balance capable of weighing objects suspended from this arm to an accuracy of ⁇ 0.05 mg in the range 0-100 mg. Mounted parallel to the balance arm is a chromel/alumel thermocouple sheathed in quartz for measuring the temperature of the gases in the tube and approximating the temperature of the object being weighed.
- TGA thermogravimetric analyzer
- the quartz tube can be lined with a sleeve of metal foil (gold, Inconel®, etc).
- the exit gases are fed to a scrubber train via rubber tubing and samples for gas chromatographic GC analysis can be withdrawn by syringe through this exit tubing. Examples 1 to 7 are obtained using Reactor #1.
- Reactor #2 consists of a 16 inch (40 cm) length of Hastelloy® C276 tubing.
- the outer diameter (OD) is 0.5 inch (1.3 cm).
- the tubing is lined with gold 0.030 inch (0.76 mm) thick.
- the inside tube diameter is 0.35 inch (089 cm).
- the reactor is heated using two ceramic band heaters that are clamped on the tubing to provide good contact.
- the first band heater, which serves as the preheater is 12 inch (30 cm) long.
- the external temperature of this preheat zone of the tube is controlled with a thermocouple attached to the outside surface of the reactor at the midpoint of the 12 inch (30 cm) section.
- the reaction zone is a 2 inch (5 cm) section that is heated in the same manner as the preheat zone.
- the controlling thermocouple is placed at midpoint of the 2 inch (5 cm) section on the outside wall of the reaction zone.
- the empty reaction zone volume of the 2 inch (5 cm) section is 3.1 ml.
- the feed and product are exposed only to the gold surface.
- the total flow through the preheater and reactor zones is 500 ml/min and is controlled by individual mass flowmeters.
- the results are obtained with the preheater control temperature set at 600° C. and reaction control temperature set at 825° C. Examples 9 to 12, 15 and 18 to 23 are obtained using the Reactor #2.
- Reactor #3 is a ⁇ fraction (3/4) ⁇ inch (1.9 cm) ID gold-lined reactor.
- the reactor outer tube material is a 16 inch (40.6 cm) length Inconel® 600 (nickel alloy) tube with a wall thickness of 0.113 inch (0.29 cm) and an OD of 1.046 inch (2.7 cm).
- the inner tube material is gold.
- the wall thickness of the gold tube is 0.039 inch (0.1 cm) and the tube ID is 0.742 inch (1.9 cm).
- thermocouples Prior to using this tube, an 8 inch (20.3 cm) portion (centered in the 16 inch (40 cm) length) is milled to an OD of ⁇ fraction (15/16) ⁇ inch (2.4 cm) so that 1 inch (2.5 cm) ID clamp-on heaters would fit snugly with enough room to position thermocouples that control and monitor temperatures.
- the preheat zone is 5 inch (13 cm) long and the reaction zone is 2 inch (5 cm) long. They are heated by a ceramic-type band heaters. Temperatures are controlled using thermocouples positioned at the center of each section on the outside wall of the tube. They are held securely in place by the heaters themselves. In addition, the outside wall temperatures in the reaction zone are also measured in three locations, inlet, midpoint and exit.
- GC/MS gas chromatographic/mass spectrometer
- a flame ionization detector with helium as the carrier.
- a small portion of the product stream from Reactors #2 and #3 is analyzed using an on-line GC/MS equipped with a 20 foot (6.1 m) ⁇ 0.125 inch (3.2 mm) steel column packed with 5% Krytox® 143AC perfluoroether on 60/80 mesh (0.25/0.18 mm) Carbopak BHT.
- GC programming conditions are set for a start temperature of 60° C. which is held for 3 minutes. It is then heated to 200° C. at the rate of 5° C./minute and held at 200° C. for 5 minutes.
- the analytical results are reported in mole %. In all the examples, product analysis shows less than 0.1% PFIB unless otherwise stated.
- Loading of the nano-size particles of gold on the alpha alumina packing is done by slurrying the packing in a solution of 0.8 g gold trichloride in 100 ml water and adding one drop HCl. The pH of the slurry is adjusted to 9.6 with sodium hydroxide solution with stirring, a solution of 1.2 g sodium citrate is added and the slurry is then left undisturbed overnight. The gold loaded packing is collected by filtration, suction dried then calcined in flowing air at 250° C. for 2 hours.
- Reactor #1 is used. A comparison of base metal versus noble metal materials of construction is carried out using the modified TGA apparatus described above which is lined with either Inconel® 600 or gold foils. A small coupon of the same metal is also suspended from the balance arm of the TGA such that weight loss (due to corrosion) or weight increase (due to coking) could be followed during the reaction.
- Table 1 lists data from comparative runs using gold and Inconel® 600 at a flow of 375:375 ml/min HCFC-22:HCFC-124 at 1 atm (100 kPa) pressure and a contact time of ⁇ 0.25 sec.
- Reactor #1 is used.
- a similar result to that of Example 1 is obtained when feeding 750 cc/min of HCFC-22 alone to the above mentioned TGA reactor when lined by gold or with Inconel® 600, as demonstrated in Table 2.
- With the Inconel® lining heavy accumulation of salts and coke plug the reactor after a few hours.
- With the gold lined reactor runs free of salts and with very light coking that can be swept away by a brush, i.e. none adheres.
- Reactor #1 is used. A direct comparison of the relative effects of noble metal surfaces on the pyrolysis chemistry is made using the modified TGA reactor described above. Each metal is examined as a foil liner in the quartz TGA tube. The conversions and selectivities are estimated at 250:250 ml/min flow of HCFC-22:HCFC-124 as in Table 3. Gold is the best metal, of those tested, in terms of low PFIB and other by-product production.
- Reactor #1 is used. Using the modified TGA reactor (without the balance arm in place), a gold-lined TGA tube is used for a comparative test wherein a flow of 375:375 ml/min HCFC-22:HCFC-124 at 1 atm (100 kPa) and a contact time of ⁇ 0.25 sec is passed through the tube.
- the tube is either empty or packed uniformly across its cross-section with 2 mm diameter fluoridated alumina spheres. The improved performance of the packed tube is illustrated in Table 4.
- Reactor #1 is used.
- a gold-lined TGA tube is used for a comparative test wherein a flow of 250 ml/min HFC-23 at 1 atm (100 kPa) is preheated to 650° C. then passed through the TGA tube at a contact time of 0.7-1.4 sec.
- the tube is packed uniformly across its cross-section with 12-13 mm fluoridated alpha alumina Raschig Rings (RR) with or without a loading of about nano size gold particles.
- the gold loading is about 1% by weight.
- There is an improved productivity by the gold loaded alpha alumina packing compared with the TGA flow reactor tube packed only with alpha alumina.
- Table 5 summarizes the results. TABLE 5 Gold lined Gold lined TGA TGA with with 12-13 1% gold loading mm alpha alumina on 12-13 mm alpha RR packing alumina RR packing Set Temp (° C.) 825 850 825 850 Gas Temp (° C.) 752 773 753 784 Conversion of HFC-23 (%) 27 41 36 58 Yield to HFP (%) 6 12 10 32 Yield to TFE (%) 18 23 20 13 g PFIB/100 g HFP formed 16.7 8.3 10. 12.5
- Reactor #1 is used.
- the effect of residence time on by-product formation, especially of PFIB, is described in Table 6.
- a gold-lined TGA tube is used for to test different residence time in the reactor by varying the flow rate of the feed from 500 to 1000 cc/min, all at the same volumetric ratio of HCFC-22 and HCFC-124, and all at a constantwall temperature of 800° C.
- Reactor #1 is used.
- Reactor #3 is used.
- the effect of temperature on the copyrolysis of HCFC-22 and HCFC-124 in a gold lined reactor is summarized in Table 8 at a constant combined flow rate of 800 cc/min at a respective ratio of 3:2 when the reactor control temperature is varied from 750° C. to 850° C. and the preheat wall temperature is controlled to 550° C. at the 3 inch (76 mm) point of the 5 inch (127 mm) long preheater that directly precedes the 2 inch (51 mm) long reactor section.
- Reactor #2 is used.
- Table 9 summarizes data obtained when either HCFC-22 or HCFC-124 is subjected to thermolysis by itself. The temperatures are presented in the form xxx/yyy; xxx being the outside wall temperature and yyy being the temperature in the gas phase in the reactor. In this example, only the wall temperature is recorded.
- HCFC-22 as the feed, high yields of TFE are produced.
- HCFC-124 as the feed, the conversion and yield are low and the major product is HFP.
- Reactor #2 is used. Table 10 provides data obtained when HCFC-124 alone is subjected to thermolysis at different contact times by varying the flow of HCFC-124. Again, HFP is observed as the main product and the yields are low.
- Reactor #2 is used. Table 11 provides data obtained when mixtures of HCFC-22 and HCFC-124 are employed. The amount of HFP relative to TFE is high. In this run, internal bulk gas temperatures corresponding to the outside wall temperature are also monitored. Thus in column 2, in the pair 731/609, the first number refers to the outside wall temperature in ° C. and the second number refers to the corresponding bulk gas temperature in ° C. monitored by a multipoint platinum-sheathed thermocouple. Both PFIB and CTFE are below the detection limit of 0.1% of the reactor effluent in these reactions.
- Reactor #2 is used, operating at a control temperature of 825° C. with the preheater operating at a control temperature of 600° C.
- the feed is a mixture of HCFC-124 (250 cc/min), HCFC-22 (150 cc/min) and perfluorocyclobutane (100 cc/min).
- Product analysis is summarized in Table 12.
- Reactor #3 is used. At a control temperature of 750° C., a mixture of HCFC-22 and HCFC-124 are passed at varying ratios. Product analysis is summarized in Table 13. Here also, the amounts of PFIB and CTFE are below 0.01%.
- Reactor #3 is used.
- Example 13 is substantially repeated except that the operating control temperature is 850° C.
- the results are summarized in Table 14.
- the peak identified as FC-1318#2 contains some PFIB as determined by mass spectrometry.
- the PFIB co-elutes with another isomer of the same molecular formula, and based on mass spectrometry it is established that about 50 to 60% of the 1318#2 found is PFIB.
- Reactor #2 is used for Example 15, which shows the result of pyrolysis of HCFC-124 and c-318 at ⁇ 815° C. reaction zone center temperature.
- Reactor #3 is used for Example 16, pyrolysis of a HCFC-124:c-318 mixture, and Example 17, pyrolysis of a HCFC-124a:c-318 mixture, both at ⁇ 700° C. reaction zone center temperature.
- the analytical results are reported in mole %. In the examples, product analysis shows less than 0.1% PFIB.
- the reaction results are summarized in Tables 15 and 16. TABLE 15 Example No.
- PFIB and CFC-1113 are both below the detection limit of about 0.1 mole % in the reactor effluent.
- Reactor #2 is used for Examples 18 to 23.
- Reactor #3 is used for Examples 24 and 25.
- Analytical results are reported in mole %. The results are summarized in Tables 17 and 18.
- Examples 18 to 22 show the effect of inert gas addition on the pyrolysis of HCFC-124. Total feed gas volume is kept constant. The production of TFE and HFP increases as the ratio of inert gas to HCFC-124 increases.
- Examples 22 and 23 show that HCFC-124a is more selective in forming TFE compared to HFP and gives TFE in much greater amount. Comparison of the results shows that 124a is more reactive and more selective to products of interest than is 124.
- Examples 24 and 25 (Table 18) show the results of pyrolysis of HCFC-124a at temperatures of about 650° C. and 750° C. TABLE 17 Example No. 18 19 20 21 22 23 Preheat zone set temp.
- Reactor #3 is used for Examples 26 and 27.
- HCFC-22:c-318 mixture is pyrolyzed at 720° C. and 746° C. Analytical results are reported in mole %. The reaction results are summarized in Table 19.
- TABLE 19 Example No. 26 27 Preheat zone Center (° C.) 548 554 Reaction zone Center (° C.) 720 746 HCFC-22 feed (cc/min) 600 600 c-318 feed (cc/min) 200 200 Results (mole %) TFE 33.3 36.4 HFP 2.5 6.0 HCFC-124a 5.8 9.6 HCFC-22 33.0 22.7 c-318 22.0 20.0 HCFC-226cb 1.5 1.7 PFIB 0.1 0.2 Others 1.3 2.2
- This example describes the production of a tube of Inconel® 600 alloy with a lining of gold according to a preferred embodiment of this invention.
- the Inconel® tube is the supporting material.
- the Inconel® tube has an outer diameter of 26.7 mm and an inner diameter of 20.9 mm and is less than one meter long.
- the gold lining is a wrought tube of the same length, having an outer diameter of 20.50 mm and an inner diameter of 18.50 mm.
- the inner surface of the Inconel® tube is honed to a finish of RMS 8 and cleaned by first degreasing with hot Oakite #3 soap solution.
- the gold tube is prepared by degreasing with an appropriate solvent, followed by acid cleaning with nitric acid (an aqueous solution made 20% by volume of 68% nitric acid in water) for 20 minutes. This is followed by rinsing with deionized water for 0.5 to 1 minute and drying.
- nitric acid an aqueous solution made 20% by volume of 68% nitric acid in water
- the gold lining is swaged onto a mandrel and pulled into the Inconel® tube.
- the lining is then mechanically expanded by drawing an expansion plug or mandrel through the gold lining.
- Increasingly larger expansion plugs are dawn through the gold lining until the calculated outer diameter of the gold lining is within the tolerances of the inner diameter of the Inconel® tube.
- the combined Inconel®-gold structure is referred to as “the tube”.
- the tube After cooling and depressurization the tube is tested to determine the extent of bonding (the ultrasonic test does not measure the quality of the bond—it determines whether a bond is present). Ultrasonic testing on this tube indicates that there is bonding on over 99% of the tube surface. Metallographic cross-sections of the tube are prepared and it is confirmed that the gold liner is bonded to the Inconel®. There is no evidence of contamination at the gold-Inconel® interface. Elemental profiles are measured and it is determined that the bond extends over about 250 ⁇ m in the radial direction, approximately centered on what had been the interface between the gold lining and the Inconel® tube when they were first assembled.
- This bonding distance is measured from the point at which the gold content is first seen to decline from 100 atom %, i.e. pure gold, to the point at which the gold content is first seen to reach 0 atom %. This confirms the interdiffusion of the gold and the supporting Inconel®, and shows that the bond between the gold and Inconel® is a metallurgical bond.
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Priority Applications (7)
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---|---|---|---|
US09/878,540 US20020032356A1 (en) | 2000-07-14 | 2001-06-11 | Synthesis of perfluoroolefins |
DE60142051T DE60142051D1 (de) | 2000-07-14 | 2001-07-13 | Herstellung von perfluorolefinen |
EP01952749A EP1301453B1 (fr) | 2000-07-14 | 2001-07-13 | Synthese d'olefines perfluorees |
CN018128289A CN1217895C (zh) | 2000-07-14 | 2001-07-13 | 全氟烯烃的合成 |
JP2002512100A JP4926365B2 (ja) | 2000-07-14 | 2001-07-13 | パーフルオロオレフィンの合成 |
PCT/US2001/022234 WO2002006193A2 (fr) | 2000-07-14 | 2001-07-13 | Synthese d'olefines perfluorees |
US11/359,807 US7271301B2 (en) | 2000-07-14 | 2006-02-22 | Synthesis of perfluoroolefins |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
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US21833800P | 2000-07-14 | 2000-07-14 | |
US27138701P | 2001-02-26 | 2001-02-26 | |
US09/878,540 US20020032356A1 (en) | 2000-07-14 | 2001-06-11 | Synthesis of perfluoroolefins |
Related Child Applications (1)
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US11/359,807 Continuation US7271301B2 (en) | 2000-07-14 | 2006-02-22 | Synthesis of perfluoroolefins |
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US20020032356A1 true US20020032356A1 (en) | 2002-03-14 |
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US09/878,540 Abandoned US20020032356A1 (en) | 2000-07-14 | 2001-06-11 | Synthesis of perfluoroolefins |
US11/359,807 Expired - Fee Related US7271301B2 (en) | 2000-07-14 | 2006-02-22 | Synthesis of perfluoroolefins |
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US11/359,807 Expired - Fee Related US7271301B2 (en) | 2000-07-14 | 2006-02-22 | Synthesis of perfluoroolefins |
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US (2) | US20020032356A1 (fr) |
EP (1) | EP1301453B1 (fr) |
JP (1) | JP4926365B2 (fr) |
CN (1) | CN1217895C (fr) |
DE (1) | DE60142051D1 (fr) |
WO (1) | WO2002006193A2 (fr) |
Cited By (8)
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---|---|---|---|---|
WO2005058780A2 (fr) * | 2003-12-17 | 2005-06-30 | E.I. Dupont De Nemours And Company | Procede de pyrolyse |
US20050241805A1 (en) * | 2004-04-29 | 2005-11-03 | Honeywell International, Inc. | Heat transfer fluid comprising 1,3,3,3-tetrafluoeopropene and carbon dioxide |
US20060094911A1 (en) * | 2004-10-29 | 2006-05-04 | Rao Velliyur N M | Noncatalytic manufacture of 1,1,3,3,3-pentafluoropropene from 1,1,1,3,3,3-hexafluoropropane |
US20060106263A1 (en) * | 2004-10-29 | 2006-05-18 | Miller Ralph N | Processes for production and purification of hydrofluoroolefins |
US20060116538A1 (en) * | 2004-10-29 | 2006-06-01 | Ralph Newton Miller | Azeotrope compositions comprising 1,1,3,3,3-pentafluoropropene and hydrogen fluoride and uses thereof |
CN114956953A (zh) * | 2022-06-21 | 2022-08-30 | 常熟三爱富氟化工有限责任公司 | 制备六氟丙烯的工艺 |
US11760707B2 (en) | 2019-11-13 | 2023-09-19 | Fujian Yongjing Technology Co., Ltd | Process for the synthesis of 2,3,3,3-tetrafluoropropene |
US20230313012A1 (en) * | 2006-06-27 | 2023-10-05 | The Chemours Company Fc, Llc | 1,2,3,3,3-pentafluropropene production processes |
Families Citing this family (5)
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CN101351430A (zh) * | 2005-11-03 | 2009-01-21 | 霍尼韦尔国际公司 | 氟化有机化合物的制备方法 |
GB201010958D0 (en) * | 2010-06-30 | 2010-08-11 | 3M Innovative Properties Co | Process for manufacturing perfluoroolefins by pyrolysis of perfluorocarbons in the presence of hydrogen |
JP2016013994A (ja) * | 2014-07-03 | 2016-01-28 | 日華化学株式会社 | テトラフルオロエチレン及び/又はヘキサフルオロプロピレンの製造方法 |
CN110420572A (zh) * | 2019-08-29 | 2019-11-08 | 江西理文化工有限公司 | 一种新型生产六氟丙烯裂解系统 |
WO2024057657A1 (fr) * | 2022-09-16 | 2024-03-21 | Agc株式会社 | Procédé de production de fluorooléfine |
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US6624337B1 (en) * | 1999-06-04 | 2003-09-23 | E. I. Du Pont De Nemours And Company | Process for the manufacture of fluoroolefins |
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NL67177C (fr) | 1939-07-01 | 1900-01-01 | ||
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US2551573A (en) | 1945-11-30 | 1951-05-08 | Du Pont | Pyrolysis of chloro-fluoro alkanes |
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US2970176A (en) | 1957-10-31 | 1961-01-31 | Du Pont | Pyrolysis of fluorocarbons to hexafluoropropylene |
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NL269647A (fr) * | 1960-09-28 | |||
US3446858A (en) | 1963-03-30 | 1969-05-27 | Daikin Ind Ltd | Process for the manufacture of hexafluoropropene |
US3397248A (en) | 1964-05-15 | 1968-08-13 | Du Pont | Process for the preparation of hexafluoropropene |
DE1236497B (de) | 1965-02-02 | 1967-03-16 | Fluorwerke Dohna | Verfahren zur Herstellung von Perfluorpropen |
US3459818A (en) | 1966-05-28 | 1969-08-05 | Asahi Glass Co Ltd | Process of producing tetrafluoroethylene and hexafluoropropylene |
US3873630A (en) | 1972-06-12 | 1975-03-25 | Du Pont | Process for pyrolyzing tetrafluoroethylene to hexafluoropropylene |
DE58904105D1 (de) | 1988-03-14 | 1993-05-27 | Hoechst Ag | Verfahren zur herstellung von hexafluorpropen. |
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EP0662861A1 (fr) * | 1992-09-22 | 1995-07-19 | E.I. Du Pont De Nemours And Company | Installation resistant a la corrosion utilisee pour produire des alcanes fortement fluores |
AU1912295A (en) * | 1994-03-11 | 1995-09-25 | E.I. Du Pont De Nemours And Company | Process for converting chlorodifluoromethane and/or dichlorodifluoromethane |
US5705719A (en) | 1996-08-01 | 1998-01-06 | E. I. Du Pont De Nemours And Company | Selective removal of perfluoroisobutylene from streams of halogenated hydrocarbons |
FR2758556B1 (fr) * | 1997-01-17 | 1999-02-19 | Atochem Elf Sa | Isomerisation d'hydrofluorocarbures |
-
2001
- 2001-06-11 US US09/878,540 patent/US20020032356A1/en not_active Abandoned
- 2001-07-13 DE DE60142051T patent/DE60142051D1/de not_active Expired - Lifetime
- 2001-07-13 CN CN018128289A patent/CN1217895C/zh not_active Expired - Fee Related
- 2001-07-13 EP EP01952749A patent/EP1301453B1/fr not_active Expired - Lifetime
- 2001-07-13 JP JP2002512100A patent/JP4926365B2/ja not_active Expired - Fee Related
- 2001-07-13 WO PCT/US2001/022234 patent/WO2002006193A2/fr active Application Filing
-
2006
- 2006-02-22 US US11/359,807 patent/US7271301B2/en not_active Expired - Fee Related
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
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US6624337B1 (en) * | 1999-06-04 | 2003-09-23 | E. I. Du Pont De Nemours And Company | Process for the manufacture of fluoroolefins |
Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100448822C (zh) * | 2003-12-17 | 2009-01-07 | 纳幕尔杜邦公司 | 热解工艺 |
WO2005058780A3 (fr) * | 2003-12-17 | 2005-09-15 | Du Pont | Procede de pyrolyse |
WO2005058780A2 (fr) * | 2003-12-17 | 2005-06-30 | E.I. Dupont De Nemours And Company | Procede de pyrolyse |
US20050241805A1 (en) * | 2004-04-29 | 2005-11-03 | Honeywell International, Inc. | Heat transfer fluid comprising 1,3,3,3-tetrafluoeopropene and carbon dioxide |
US9884946B2 (en) | 2004-04-29 | 2018-02-06 | Honeywell International Inc. | Compositions containing tetrafluoropropene and carbon dioxide |
US7655610B2 (en) * | 2004-04-29 | 2010-02-02 | Honeywell International Inc. | Blowing agent compositions comprising fluorinated olefins and carbon dioxide |
US7897823B2 (en) | 2004-10-29 | 2011-03-01 | E. I. Du Pont De Nemours And Company | Process for production of azeotrope compositions comprising hydrofluoroolefin and hydrogen fluoride and uses of said azeotrope compositions in separation processes |
US20060116538A1 (en) * | 2004-10-29 | 2006-06-01 | Ralph Newton Miller | Azeotrope compositions comprising 1,1,3,3,3-pentafluoropropene and hydrogen fluoride and uses thereof |
US20060106263A1 (en) * | 2004-10-29 | 2006-05-18 | Miller Ralph N | Processes for production and purification of hydrofluoroolefins |
US20110118512A1 (en) * | 2004-10-29 | 2011-05-19 | E.I. Du Pont De Nemours And Company | Processes for production and purification of hydrofluoroolefins |
US8399723B2 (en) | 2004-10-29 | 2013-03-19 | E I Du Pont De Nemours And Company | Processes for production and purification of hydrofluoroolefins |
US20060094911A1 (en) * | 2004-10-29 | 2006-05-04 | Rao Velliyur N M | Noncatalytic manufacture of 1,1,3,3,3-pentafluoropropene from 1,1,1,3,3,3-hexafluoropropane |
US20230313012A1 (en) * | 2006-06-27 | 2023-10-05 | The Chemours Company Fc, Llc | 1,2,3,3,3-pentafluropropene production processes |
US11912923B2 (en) * | 2006-06-27 | 2024-02-27 | The Chemours Company Fc, Llc | 1,2,3,3,3-pentafluropropene production processes |
US12110444B2 (en) | 2006-06-27 | 2024-10-08 | The Chemours Company Fc, Llc | 1,2,3,3,3-pentafluropropene production processes |
US11760707B2 (en) | 2019-11-13 | 2023-09-19 | Fujian Yongjing Technology Co., Ltd | Process for the synthesis of 2,3,3,3-tetrafluoropropene |
CN114956953A (zh) * | 2022-06-21 | 2022-08-30 | 常熟三爱富氟化工有限责任公司 | 制备六氟丙烯的工艺 |
Also Published As
Publication number | Publication date |
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JP2004504283A (ja) | 2004-02-12 |
US20060142622A1 (en) | 2006-06-29 |
DE60142051D1 (de) | 2010-06-17 |
CN1217895C (zh) | 2005-09-07 |
EP1301453B1 (fr) | 2010-05-05 |
WO2002006193A2 (fr) | 2002-01-24 |
US7271301B2 (en) | 2007-09-18 |
EP1301453A2 (fr) | 2003-04-16 |
WO2002006193A3 (fr) | 2002-07-25 |
JP4926365B2 (ja) | 2012-05-09 |
CN1441760A (zh) | 2003-09-10 |
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