KR102354556B1 - Process for the manufacture of hydrochlorofluoroolefins - Google Patents

Abstract

The present disclosure provides for fluorination of 1230za and/or 240fa with a cis/trans mixture of 1-chloro 3,3,3-trifluoropropene (1233zd), cis 1233zd in a fluorination step after separation of trans isomers Provided is a method for preparing trans 1-chloro 3,3,3-trifluoropropene (trans 1233zd) by isomerizing to trans 1233zd. The fluorination step is carried out in the gas phase or in the liquid phase. Isomerization is carried out in the gas phase using either supported or unsupported high surface area heterogeneous Cr catalysts.

Description

Method for producing hydrochlorofluoroolefin

The present invention relates to a process for the preparation of hydrochlorofluoroolefins.

The Montreal Protocol for the Protection of the Ozone Layer directs the phasing out of chlorofluorocarbons (CFCs). Substances more “friendly” to the ozone layer, such as hydrofluorocarbons (HFCs), such as 134a, have replaced chlorofluorocarbons. Chlorofluorocarbon compounds have been proven to cause global warming by becoming greenhouse gases, and could be regulated by the Kyoto Protocol on Climate Change. There is a need for alternative materials that are environmentally acceptable, ie, have a negligible ozone depletion potential (ODP) and an acceptable low global warming potential (GWP). The present invention relates to thermosetting and thermoplastic foams; menstruum; heat transfer fluids such as in heat pumps; and hydrochlorofluoroolefins useful as low ODP and low GWP blowing agents in refrigerants such as low pressure refrigerants for cooling applications, i.e. trans 1233zd (E-1233zd, 1-chloro-3,3,3-trifluoropropene) Describe the manufacturing method.

US Patent Publications US2008/0051610 and US2008/0103342 disclose a process comprising a catalytic isomerization step from cis 1234ze to trans 1234ze. US 7,420,094 discloses the isomerization of 1234ze to 1234yf using a Cr-based catalyst. US 8,217,208 discloses a process for the isomerization of 1-chloro-3,3,3-trifluoropropene from one isomer to another, comprising the step of contacting a feed stream with a heated surface. US 2008/0051611 discloses recovery of trans 1234ze via distillation from a mixture comprising cis 1234ze and trans1234ze.

The present invention relates to a process for the preparation of hydrochlorofluoroolefins, i.e. trans 1-chloro-3,3,3-trifluoropropene (E-1233zd). The method comprises an isomerization step from cis 1233zd (Z-1233zd) to trans 1233zd (E-1233zd).

1 is a schematic diagram of a liquid phase process according to the present invention;
2 is a schematic diagram of a gas phase process according to the present invention;

The present invention provides a process for the preparation of trans 1-chloro-3,3,3-trifluoropropene (E-1233zd). _{The first step of the process is 1,1,3,3-tetrachloropropene (1230za, CCl 2} =CH—CHCl ₂ ) by forming a chloroalkane through the addition of an olefin to the starting chloroalkane and reacting the chloroalkane and/or forming 1,1,1,3,3-pentachloropropane (240fa). System of 1,1,3,3-tetrachloro-propene _{(1230za, CCl 2 = CH-} CHCl 2) and / or 1,1,1,3,3-penta-chloropropane (240fa) in the next step 1233zd ( A fluorination step is followed which includes fluorination with a mixture of Z-1233zd) and trans 1233zd (E-1233zd). This step is followed by a separation step comprising separation of the mixture formed in the first step to isolate cis 1233zd (Z-1233zd) from the mixture. This step is followed by an isomerization step comprising the isomerization of cis 1233zd (Z-1233zd) to trans 1233zd (E-1233zd).

The 1,1,1,3,3-pentachloropropane (240fa) or 1,1,3,3-tetrachloropropene (1230za) feedstock is usually added to an addition reaction followed by steps such as chlorination or hydrogen halide removal. It is a chlorinated compound prepared using

The production of chloroalkanes such as 240fa, 250fb, 240db and 230da by addition of olefins to the starting chloroalkane is well known in the art. For example, 240fa is generally prepared by the addition of carbon tetrachloride to vinyl chloride using a catalyst and a cocatalyst. A cocatalyst is typically an organic ligand capable of forming a complex with the catalyst to transport the catalyst into solution. The process can be carried out batchwise or preferably continuously. The production system may be closed to provide complete recycle of the unreacted feed material haloalkanes and haloalkenes.

Useful starting chlorooalkane feedstocks for the preparation of the 1,1,1,3,3-pentachloropropane (240fa) or 1,1,3,3-tetrachloropropene (1230za) feedstock of the present invention include carbon tetrachloride, While chloroform and methyl chloride are included, useful olefins include ethylene, vinyl chloride, 1,1-dichloroethene, 1,2-dichloroethene, trichloroethylene, tetrachlorethylene and chlorofluoroethylene.

An exemplary reaction of a starting chloroalkane and an olefin is

Addition of carbon tetrachloride to ethylene to give 1,1,1,3-tetrachloropropane (250 fb)

Addition of carbon tetrachloride to vinyl chloride to give 1,1,1,3,3-pentachloropropane (240fa)

Addition of methylene chloride to trichloroethylene to give 1,1,1,2,3-pentachloropropane (240 db)

Addition of carbon tetrachloride to 1,2-dichloroethylene to give 1,1,1,2,3,3-hexachloropropane (230da)

includes

Useful catalysts in the reaction of the starting chloroalkanes and olefins include cuprous compounds, iron powder, iron chloride, organonickel compound catalysts or organocopper catalysts. The cocatalyst may be selected from chelating agents and may act as solvents. Suitable ligands are selected from amines, amides, nitriles and organophosphate solvents.

The chloroalkanes produced, such as 240fa, 250fb, 240db and 230da, are further reacted through, for example, chlorination or hydrogen halide removal to obtain the desired 1,1,1,3,3-pentachloropropane (240fa) or 1,1, A 3,3-tetrachloropropene (1230za) feedstock is produced.

In one embodiment, the further reaction is a chlorination step. More specifically, 250 fb can be chlorinated to produce a mixture of 1,1,1,3,3-pentachloropropane (240fa) and 1,1,1,2,3-pentachloropropane (240db). This chlorination can be carried out via photochlorination.

In a second embodiment, the further reaction is a dehydrochlorination step. More specifically, 240fa can be dehydrochlorinated to give 1230za. The dehydrochlorination step can be carried out as a gas phase or liquid phase process in the presence or absence of a catalyst.

In a third embodiment, the further reaction is a dechlorination step. More specifically, 230da can be dechlorinated to give 1230za. To complete this dechlorination, methods known in the art such as using zinc powder to complete this dechlorination reaction can be used.

The present invention provides 1,1,3,3-tetrachloropropene (1230za, CCl ₂ =CH-CHCl ₂ ) and/or 1,1,1,3,3-tetrachloropropane (240fa) comprising the steps of: ) to a process for producing trans 1-chloro-3,3,3-trifluoropropene (E-1233zd) from:

a) forming a chloroalkane through addition of an olefin to the starting chloroalkane and reacting the chloroalkane with 1,1,3,3-tetrachloropropene (1230za, CCl ₂ =CH-CHCl ₂ ) and/or 1, forming 1,1,3,3-pentachloropropane (240fa); next

b) fluorination of 1,1,3,3-tetrachloropropene (1230za, CCl ₂ =CH-CHCl ₂ ) and/or 1,1,1,3,3-pentachloropropane (240fa) in the gas phase or liquid phase fluorination of 1230za to obtain a mixture of cis(Z) and trans(E) 1-chloro-3,3,3 trifluoropropene (1233zd, CF ₃ -CH=CHCl); next

c) cis (Z) 1-chloro 3,3,3-trifluoropropene (1233zd, CF ₃ -CH=CHCl) and trans (E) 1-chloro 3,3,3-trifluoropropene ( 1233zd, CF ₃ -CH=CHCl); next

d) isomerization of cis 1233zd (Z-1233zd) from the second step to form trans 1233zd (E-1233zd).

The fluorination step of the above process, ie, gas phase fluorination from 1230za and/or 240fa to 1233zd or liquid phase fluorination from 1230za to 12333zd, may be via any process known in the art. For example: unaccelerated liquid phase fluorination of 1230za is disclosed in US Pat. No. 5,877,359; The accelerated gas phase fluorination of 1230za is disclosed in US Pat. No. 5,811,603; U.S. Patent No. 6,166,274 discloses the fluorination of 1230za to 1233zd in the presence of a catalyst such as trifluoroacetic acid or triflic acid. Fluorination catalysts such as TiCl ₄ , TiF ₄ , SnCl ₄ , SnF ₄ , SbF ₅ , SbCl ₅ , SbF _x Cl _y (x+y=5) or ionic liquids are described in US Pat. No. 6,881,698. When an Sb type catalyst is used, it is desirable to supply a _{low level of Cl 2 to keep the Sb species in an active form.}

The separation step of the process comprises the separation of the cis 1233zd and trans 1233zd formed in the first step through suitable separation means such as distillation, liquid phase separation or extractive separation. The cis 1233zd and trans 1233zd formed in the first step may contain HF and HCl. Preferably, HCl is first removed in the first distillation column. Thereafter, HF can be removed using liquid phase separation combined with azeotropic distillation. The difference in boiling point of cis 1233zd and trans 1233zd may allow separation of cis 1233zd and trans 1233zd by conventional distillation, typically at atmospheric pressure.

The isomerization step of the process involves the cis 1233zd to trans 1233zd isomerization from the separation step. The isomerization step can be carried out in the gas phase using heterogeneity or in a liquid phase uncatalyzed reaction or in a liquid phase catalyzed reaction using a homogeneous catalyst.

The isomerization step can be accomplished by a gas phase process in the presence of a heterogeneous catalyst. ^{Suitable heterogeneous catalysts are supported or unsupported high surface area Cr(III)} catalysts, which may optionally contain low levels of one or more cocatalysts selected from cobalt, nickel, zinc or manganese. For supported catalysts, the catalyst support may be selected from materials known in the art that are compatible with high temperature and high pressure processes. For example, fluorinated alumina, HF treated activated carbon or graphite carbon are suitable catalyst supports. A preferred catalyst is a high surface area unsupported chromium oxide catalyst activated with HF prior to use, optionally at a pressure greater than 50 psi. If present, the level of cocatalyst may vary from 1% to 10%, preferably from 1% to 5% by weight of the catalyst. The cocatalyst may be added to the catalyst by processes known in the art, such as adsorption from an aqueous or organic solvent followed by evaporation of the solvent.

Suitable heterogeneous catalysts may also be selected from Lewis acid supported catalysts selected from ^{Sb V} , Ti ^IV , Sn ^IV , Mo ^VI , Nb ^v and Ta ^{v .} The support itself may be fluorinated alumina; fluorinated chromia; selected from the group such as HF activated carbon or graphite carbon. Supported antimony halides such as SbF ₅ are described in US Pat. No. 6,528,691 and are preferred catalysts. Other solid catalysts may also be used, such as NAFION ^® type polymers, acidic molecular sieves, and zeolites.

For gas phase processes, the temperature may vary from 20°C to 500°C, preferably from 100°C to 400°C. The contact time may vary from 0.5 seconds to 100 seconds. Low levels of an oxidizing agent, such as oxygen, or an oxygen containing gas, such as air or chlorine gas, may be used at 0.01% to 0.1% by volume to extend catalyst life.

The isomerization step also preferably comprises metal compounds of groups 3, 4, 5, 13, 14 and 15 of the Periodic Table of the Elements (IUPAC 1988) and mixtures thereof (formerly IIIA, IVa, IVb, Va, Vb). and compounds of the periodic table of the elements called group VIb) in the presence of a homogeneous catalyst selected from the group consisting of uncatalyzed or catalyzed reactions in a liquid phase process. Metal compounds are intended to include hydroxides, oxides and organic or inorganic salts of these metals, as well as mixtures thereof. Preference is given to aluminum, titanium, tantalum, molybdenum, boron, tin and antimony derivatives such as AlCl ₃ , TiCl _{4 , TaCl 5} , MoCl ₆ , BF ₃ , SnCl ₄ and SbCl ₅ . In the process according to the invention, preferred derivatives of metals are salts, which are preferably halides, more particularly chlorides, fluorides and chlorofluorides, such as AlF ₃ , TiF ₄ , _{TaF 5} , MoF ₆ , SnF ₄ , SbF _{5 .} , SbF _x Cl _y (x+y)=5. The catalyst must be activated (HF or any molecule capable of exchanging fluorine) before the isomerization step. In the case of an antimony type catalyst, a low level of chlorine gas can be used as an oxidizing agent to keep the antimony catalyst in a pentavalent oxidation state. In addition to the aforementioned Lewis acid catalysts, ionic liquids derived from antimony, titanium, niobium and tantalum are suitable for liquid phase fluorination processes. A description of the preparation of such a catalyst is disclosed in US Pat. No. 6,881,698.

Homogeneous catalysts for the liquid phase promoted process also include sulfuric acid H ₂ SO ₄ ; sulfonic acid type acids such as ClSO ₃ H or FSO ₃ H; or triflic acid CF ₃ SO ₃ H; or from the Bronsted type family of acids such as, but not limited to, methane sulfonic acid CH ₃ SO _{3 H.} For liquid phase processes, the operating temperature is about 20° C. to 200° C., and the contact time can vary from about 0.5 hour to 50 hours.

The process of the present invention may include additional separation steps between each step. The purpose of these separations is to

1. removal of any hydrogen acids (HF, HCl), in whole or in part, from the flow, if necessary; or

2. isolating the desired product for feeding in a subsequent step, or

3. Purifying the product and removing organic impurities or by-products; or

4. Drying the product ( _{removing H 2} O)

can be the same as

The means used to accomplish these additional steps are known in the art and include, but are not limited to, distillation, extractive distillation or adsorption.

The process of the present invention is illustrated in the figure presenting block flow diagrams of gas phase and liquid phase processes according to the present invention. In the drawings, processes are presented in the form of process modules designed to achieve specific purposes and arranged according to the purposes of the present invention. These modules include:

RFL —Contains a rectification system comprising a liquid phase fluorination reactor and a non-agitated, jacketed pressure vessel connected to a rectification column. The reactor also acts as a reboiler of the rectification column. HF and organics 1230za are fed directly to the reactor. The molar feed ratio of HF to organics is governed by the reaction stoichiometry and by the amount of HF leaving the reactor with the rectification column overhead and the liquid phase purge. Mixing is provided by the boiling action of the reactor contents. Usually, the reactor effluent leaves the reactor vessel as a gas and enters the bottom of the rectification column. A small purge from the liquid phase can remove any non-volatiles that may have formed during the reaction. Rectification columns contain packings or trays designed to provide good mass transfer between the gas flowing upwards and the liquid flowing downwards. At the top of the column the condenser is cooled by cooling water, cold water or some type of refrigeration. The condenser is a partial condenser in which the liquid eluate is refluxed directly back to the column. The vapor effluent consists of HCl, HF and organic components.

Pure HCl is removed from the top of the distillation column by including a DH - HCl distillation system. This column can operate between 100 psig and 300 psig. More typically, the HCl is distilled above 120 psig to allow the use of conventional (-40C) cooling at the top of the HCl column. The bottom of this column contains HF and organics with a small residual amount of HCl. The ratio of HF to organic component is usually close to the azeotrope composition.

PS - contains a liquid phase separator for separating two liquid phases, one consisting mainly of hydrochlorofluorocarbon (HCFC) and the other mainly consisting of HF. The HF phase is usually less dense, so the HF phase exits from the top of the phase separator and the HCFC exits as the bottom phase. There is some HF in the HCFC phase and some HCFC in the HF phase. However, the composition of both phases is not related to any azeotropic composition. The operating temperature of the phase separator may be -40°C to +20°C. However, the lower the temperature, the better the phase separation.

DA - comprises an azeotropic distillation column in which an azeotropic composition of HF and organics consisting of one or more HCFCs (hydrochlorofluorocarbons) and HFCs (hydrofluorocarbons) is distilled overhead. These organic compounds may be saturated or olefinic. The bottom composition is fully HF or completely organic depending on whether the column feed composition is on the HF rich side or the organics rich side of the azeotrope. If the bottom is HF, this vapor is usually recycled back to the reactor. If the bottom vapor is organic, it is sent to a traditional distillation train.

DS - includes straight distillation usually done under pressure.

RI —Includes gas-phase isomerization reactions that are customarily conducted at temperatures above 400° C. in adiabatic, packed bed reactors. The module consists of a feed vaporizer and a superheater. This may include an “economizer” whereby the hot effluent is fed to one side and the relatively cold reactor feed gas is fed to the other side of the heat exchanger. The effluent gas is further cooled before entering the distillation column. Isomerization reactions can be carried out in various transformations depending on the equilibrium distribution of isomers. Eluate isomers can have very close boiling points together. However, they usually appear close to ideal behavior and can therefore be isolated by traditional distillation. As an alternative to the gas phase, this reaction can be carried out as a uniformly promoted liquid phase reaction. In this configuration, the reactor will be a continuously stirred tank in which the effluent is removed as a vapor to achieve separation from the catalyst.

RFG - Includes gas phase fluorination reactors, which are adiabatic packed bed reactors that feed the gas phase via a solid catalyst. No cooling is required because the reactor has a low conversion per pass and a high HF molar feed ratio. The adiabatic exotherm is usually less than 100°C. Feed HF and organics are vaporized in a conventional vaporizer and superheated to reactor temperature. Conventional vaporizers minimize thermal degradation by allowing 1230za and/or 240fa to vaporize at a lower temperature than would be possible if it vaporized as a pure component. This module also includes an "economizer" whereby the hot effluent is fed to one side and the relatively cold reactor feed gas is fed to the other side of the heat exchanger. The effluent gas is further cooled before entering the distillation column. The reaction temperature is 200°C to 400°C. The pressure is high enough to allow the HCl by-product to be distilled using conventional refrigeration, preferably between 100 psig and 200 psig.

The lowercase letters used to identify a module distinguish multiple appearances of the same type of module in the same process.

1 is a block flow diagram of a process according to the present invention for converting 1230za to E-1233zd using a liquid phase fluorination step. The figure includes the process modules described above. 1 discloses a process in which 1230za and HF are fed to the reaction module RFL-1. Typically, the reaction takes place in a medium that is predominantly HF rich in the absence of a catalyst. HCl and 1233zd/HF exit the top of the rectification column of RFL-1. The vapor effluent of RFL-1 is fed to DH-1 to remove HCl as a pure overhead product. The lower part of DH-1 consists mainly of 1233zd (both E and Z isomers) and HF in a near azeotropic composition. This is fed to module PS-1 to achieve liquid phase separation. The top HF rich phase is sent to module DA-1a, where HF is separated as a bottoms stream for recycling to the reactor. The overhead azeotrope of 1233zd and HF is recycled back to DH-1 to allow any residual HCl and light organics to be stripped out of this column before the azeotrope is recycled for phase separation. The bottoms stream from PS-1 goes to module DA-1b, which removes an organic stream free of HF as bottoms stream. The overhead from DA-1b is recycled to DH-1 for the same reason that the DA-1a azeotrope is recycled to DH-1. The bottom of DA-1b is sent to process module DS-1 which separates any heavy material from 1233zd. The overhead from DS-1 is E-1233zd, the desired trans isomer. Z-1233zd boils higher and is withdrawn for supply to process module RI-1. The effluent from the isomerization reactor is recycled to DS-1 to achieve separation of the E and Z isomers.

2 is a block flow diagram of a process according to the present invention for converting 1230za or 240fa to E-1233zd using a gas phase fluorination step. The figure includes the process modules described above. The process in FIG. 2 is similar to FIG. 1 except, for example, the liquid phase fluorination reactor (RFL-1) is replaced by a gas phase fluorination reactor (RFG-1) and an azeotropic distillation column (DA-2a). .

The process as outlined by Figure 2 includes feeding 1230za and/or 240fa and HF to the reaction module RFG-2. The reaction takes place in the gas phase using a catalyst. The reactor effluent consists predominantly of HCl, 1233zd, unreacted 1230za and excess HF. The reactor effluent of RFG-2 enters DA-2a to remove HF and unreacted F1230za as bottoms recycled to the reactor. The overhead consisting predominantly of HCl and an azeotrope of HF with 1233zd (both E and Z isomers) is sent to DH-2, which removes HCl as a pure overhead product. The bottom of DH-2 consists mainly of 1233zd (both E and Z isomers) and HF in near azeotropic composition. This is fed to module PS-2 to achieve liquid phase separation. The top HF rich phase is sent to module DA-2b, where HF is separated as a bottoms stream for recycle to the reactor. The overhead azeotrope of 1233zd and HF is recycled back to DH-2 allowing any residual HCl and light organics to be stripped out of this column before the azeotrope is recycled for phase separation. The bottoms stream from PS-2 goes to module DA-2c, which removes an organic stream free of HF as bottoms stream. The overhead from DA-2c is recycled to DH-2 for the same reason that the DA-2b azeotrope is recycled to DH-2. The bottom of DA-2c is sent to process module DS-2 which separates any heavy material from 1233zd. The overhead from DS-2 is E-1233zd, the desired trans isomer. Z-1233zd boils higher and is withdrawn for supply to process module RI-2. The effluent from the isomerization reactor is recycled to DS-2 to achieve separation of the E and Z isomers.

Claims (15)

- Carbon tetrachloride is added to ethylene to form 1,1,1,3-tetrachloropropane (250fb), and methylene chloride is added to trichloroethylene to form 1,1,1,2,3-pentachloropropane (240db) olefin to the starting chloroalkane via a reaction selected from the group consisting of formation, and addition of carbon tetrachloride to 1,2-dichloroethylene to form 1,1,1,2,3,3-hexachloropropane (230da) 1,1,1,3-tetrachloropropane (250fb), 1,1,1,2,3-pentachloropropane (240db) and 1,1,1,2,3,3-hexachloro by the addition of forming a chloroalkane product selected from the group consisting of propane (230da); next
- 1,1,3,3-tetrachloropropene (1230za, CCl ₂ =CH-CHCl ₂ ) and/or 1,1,1,3,3-pentachloropropane (240fa) by reacting the chloroalkane product forming a; next
-cis 1233zd (Z-1233zd) and trans 1233zd (E-1233zd) of 1,1,3,3-tetrachloropropene (1230za) and/or 1,1,1,3,3-pentachloropropane (240fa) ) to a mixture comprising; next
- separation of said cis 1233zd (Z-1233zd) from said trans 1233zd (E-1233zd); next
- isomerization of the cis 1233zd (Z-1233zd) to form trans 1233zd (E-1233zd)
Trans 1-chloro 3,3,3 trifluoro from 1,1,3,3-tetrachloropropene (1230za) and/or 1,1,1,3,3-pentachloropropane (240fa) comprising A method for preparing lopropene (E-1233zd). The process according to claim 1 , wherein the addition of the olefin to the starting chloroalkane is in the presence of at least one catalyst. The method of claim 2 , wherein the at least one catalyst is selected from the group consisting of a cuprous compound, iron powder, iron chloride, an organonickel compound and an organocopper compound. The method of claim 1 , wherein reacting the chloroalkane product comprises chlorination or dehydrochlorination. The method according to claim 1 , wherein the isomerization process is carried out in gas phase or liquid phase. 6. Sb ^V ; Ti ^IV ; Sn ^IV ; Mo ^VI ; The process is carried out in the liquid phase using a heterogeneous catalyst selected from the group consisting of a Lewis acid catalyst selected from ^{Nb V} or Ta ^{V and a Bronsted acid catalyst.} 7. The method of claim 6, wherein the soluble Lewis acid catalyst is selected from the group consisting of fluorinated alumina; fluorinated chromia; supported on a support selected from the group of previously fluorinated activated carbon or graphite carbon. 7. The method of claim 6, wherein the Bronsted acid catalyst is selected from the group consisting of triflic acid, methanesulfonic acid, sulfuric acid and sulfonic acid. The process according to claim 5 , wherein the isomerization is carried out in the liquid phase in the absence of a catalyst. The method of claim 5 , wherein the isomerization is carried out in the gas phase using a supported or unsupported high surface area heterogeneous Cr catalyst. 11. The method of claim 10, wherein the catalyst further comprises a co-catalyst selected from the group consisting of Co, Ni, Zn and Mn. delete delete delete delete

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