GB2535512A

GB2535512A - Process

Info

Publication number: GB2535512A
Application number: GB1502814.5A
Authority: GB
Inventors: Sharratt Andrew; Jayne Hodgson Emma; Doran Maxine; Charles Mccarthy John; Andrew Flaherty Stephen
Original assignee: Mexichem Fluor SA de CV
Current assignee: Mexichem Fluor SA de CV
Priority date: 2015-02-19
Filing date: 2015-02-19
Publication date: 2016-08-24
Also published as: GB201502814D0; WO2016132111A1

Abstract

A process for producing trifluoromethyl acetylene (TFMA), the process comprising converting trans-1-chloro-3,3,3-trifluoropropene (Z-1233zd) to TFMA in the presence of at least one base, wherein the process is conducted in the presence of water. Preferred bases include alkali metal and alkaline earth metal bases. More preferably, the base is selected from lithium hydroxide, sodium hydroxide and most preferably, potassium hydroxide. Preferably, the process is conducted in the absence of methanol and/or a phase transfer catalyst. The Z-1233zd may be prepared by hydrofluorinating 1,1,1,3,3-pentachloropropane or 1,1,3,3-tetrachloropropene in the presence or absence of a hydrofluorination catalyst, such as Lewis acid metal halides. Alternatively, a process for preparing a tetrafluoropropene, the process comprising contacting the TFMA with hydrogen fluoride (HF) in the presence of a fluorination catalyst to produce a tetrafluoropropene is described. Preferred tetrafluoropropenes include 1234yf and 1234ze. Preferred fluorination catalysts include Lewis acid metal halides such as Sb(V) halides, preferably SbF5.

Description

Intellectual Property Office Application No. GII1502814.5 RTM Date:25 November 2015 The following terms are registered trade marks and should be read as such wherever they occur in this document: Hastelloy (page 3) Intellectual Property Office is an operating name of the Patent Office www.gov.uk /ipo Process This invention relates to a process for preparing trifluoromethyl acetylene (TFMA). In particular, the invention relates to a process for preparing TFMA from trans-1-Chloro-3,3,3-trifluoropropene (Z-1233zd), and also the preparation of a tetrafluoropropene from TFMA.

Products with reduced Global Warming Potential (GWP) based on hydrofluoroolefins (HFOs) are starting to replace hydrofluorocarbons (HFCs) for many applications. In particular, the demand for the hydrofluoroolefins 2,3,3,3-tetrafluoropropene (1234y1) and 1,3,3,3-tetrafluoropropene (1234ze) is expected to grow significantly in the future.

Trifluoromethyl acetylene (TFMA) may provide a useful intermediate in the production of (hydro)halocarbons, such as tetrafluoropropenes, which have been identified as potential replacements for saturated fluorocarbons and other hydrohalocarbons in many applications. In particular, TFMA may be useful as an intermediate in the production of 1234yf and/or 1234ze.

There is therefore a need for a reliable and efficient process for the production of TFMA.

The present invention provides a process for the preparation of TFMA. The process comprising converting Z-1233zd to TFMA in the presence of at least one base, wherein the process is conducted in the presence of water.

Typically, in the process of the invention for producing TFMA, Z-1233zd is converted to 25 TFMA by adding at least one base to Z-1233zd, wherein the process is conducted in the presence of water.

For example, in the process of the invention for producing TFMA, the at least one base may be added to an aqueous solution of Z-1233zd or an aqueous solution of the at least 30 one base may be added to Z-1233zd or an aqueous solution of the at least one base may be added to an aqueous solution of Z-1233zd.

Alternatively, in the process of the invention for producing TFMA, an aqueous solution of Z-1233zd may be added to the at least one base or Z-1233zd may be added to an aqueous solution of the at least one base or an aqueous solution of Z-1233zd may be added to an aqueous solution of the at least one base.

Examples of methods in which the at least one base or Z-1233zd may be added to the process include, but are not limited to, using a dropping funnel or a syringe. At industrial scale, the Z-1233zd can be introduced into the process in any known manner, for example under gravity, pumping or as a vapour following evaporation Typically, in the process of the invention for producing TFMA, the at least one base or Z1233zd are added to the reaction in a controlled manner. Examples of controlled addition include, but are not limited to, the use of a dropping funnel or a syringe pump.

The present invention provides a process for the preparation of TFMA, the process comprising: (i) introducing Z-1233zd to a reactor; (ii) adding at least one base; and (iii) collecting the product TFMA.

Typically, in the process of the invention for producing TFMA, Z-1233zd and/or the at least one base are added to the reaction in the form of an aqueous solution.

The process of the invention for producing TFMA may be conducted in the vapour and/or liquid phase. Preferably, the process is conducted in the liquid phase.

By the term "in the presence of water" we mean that the reaction is conducted using water as a solvent. Typically, water is present as the only solvent, such that Z-1233zd and/or the at least one base are added to the process in the form of an aqueous solution.

However, it is to be appreciated that other solvents may be present so long as they do not interfere with the process of the invention.

The process of the invention for producing TFMA may be conducted in the absence of alcohol, for example in the absence of methanol.

It has been surprisingly found by the present inventors, that when the process of the invention is conducted in the absence of methanol, the formation of the by-product 1-methoxy-3,3,3-trifluoropropene, can be avoided.

As used herein, the term "water" encompasses water that may also comprise suspended and/or dissolved compounds or compositions. To avoid possible problems of contamination it may be considered desirable to use purified water, for example distilled water or deionised water.

Typically, in the process of the invention for producing TFMA, a phase transfer catalyst is not present. It has been found by the present inventors, that when the process of the invention is conducted in the absence of phase transfer catalyst, the formation of polymers of Z-1233zd and/or TFMA can be avoided, resulting in an increase in the conversion of Z- 1233zd to TFMA.

The process of the invention for producing TFMA may typically be conducted at a temperature of from about -100 to about 100 °C, such as from about -50 to about 70 °C or -10 to about 50 °C, e.g. from about 0 to about 60 °C or about 20 to about 40 °C.

The process of the invention for producing TFMA may typically be conducted at a pressure of from about 0 to about 30 bara, such as from about 0.1 to about 20 bara or from about 0.5 to about 10 bara, e.g. from about 1 to about 5 bara.

The process of the invention for producing TFMA may typically be conducted over a period of from about 1 to about 10 hours, such as from about 2.5 to about 7.5 hours, or about 5 hours.

The process of the invention for producing TFMA may typically convert from about 80 to 25 about 100% Z-1233zd to TFMA, for example from about 85 to about 95%, with from about 90 to about 100% selectivity for TFMA, such as from about 90 to about 95%.

The process of the invention for producing TFMA may typically be carried out in any suitable apparatus, such as a static mixer, a tubular reactor, a stirred tank reactor or a stirred vapour-liquid disengagement vessel. The process of the invention for producing TFMA may be conducted using an autoclave and a cold trap, such as a Whitey bomb in a dry ice/acetone bath. Preferably, this apparatus and any other apparatus described herein is made from one or more materials that are resistant to corrosion, e.g. Hastelloy® or Inconel®.

In the process of the invention for producing TFMA, the TFMA product may typically be removed as it is formed. For example, the TFMA product may be continually removed via a cold trap, such as a Whitey bomb in a dry ice/acetone bath.

The process may be carried out batch-wise or continuously.

Any suitable base may be used. Suitable bases include, but are not limited to alkali metal bases and alkali earth metal bases. For example, the at least one base may be selected from the group consisting of Li0H, NaOH, KOH and combinations thereof.

Typically, the molar ratio of at least one base:Z-1233zd in the process of the invention for producing TFMA is from about 10:1 to about 1:10, for example from about 4:1 to about 1:4, for example from about 3:1 to about 2:1, preferably with excess base, or at least 1:1.

The Z-1233zd used for this invention can be produced by any known means, for example by hydrofluorination of 1,1,1,3,3-pentachloropropane or 1,1,3,3-tetrachloropropene in the presence or absence of a catalyst.

Accordingly, the present invention provides a process for producing TFMA, the process comprising: (i) hydrofluorinating 1,1,1,3,3-pentachloropropane or 1,1,3,3-tetrachloropropene in the presence or absence of a hydrofluorination catalyst to produce Z-1233zd; and (ii) converting the Z-1233zd obtained in step (i) to TFMA in the presence of at least one base, wherein the process is conducted in the presence of water, as described above.

Suitable hydrofluorination catalysts, when used, for step (i) above include Lewis acids such as Lewis acid metal halides of Ti(IV), Ta(V), Sn(IV) and Sb(V).

The process of the invention for producing TFMA, may comprise converting Z-1233zd to TFMA, wherein the at least one base, such as KOH, is added to Z-1233zd in a controlled manner, for example by drop-wise addition, in the absence of a catalyst, such as a phase transfer catalyst, at a temperature of from about 20 to about 40 °C, wherein the TFMA product is continually removed from the process.

In a further aspect of the invention, TFMA may be fluorinated to produce a tetrafluoropropene such as 1234yf and/or 1234ze.

In the process of the invention for producing a tetrafluoropropene such as 1234yf and/or 1234ze, TFMA is contacted with hydrogen fluoride (HF) in the presence of a fluorination catalyst.

In the process of the invention for producing a tetrafluoropropene such as 1234yf and/or 1234ze, the TFMA may be prepared by a process of the invention as described above or may be obtained from a source other than the process described above.

In the process of the invention for producing a tetrafluoropropene such as 1234yf and/or 1234ze, when the TFMA is prepared using a process of the invention as described above, any suitable fluorination catalyst may be used in the process of the invention for producing a tetrafluoropropene such as 1234yf and/or 1234ze, including but not limited to catalysts comprising activated carbon, alumina and/or an oxide of a transition metal and supported (e.g. on carbon) or unsupported Lewis acid metal halides, including TaX5, SbX5, SnX4, TiXa, FeCl3, NbX5, VX5, AIX3 (wherein X = F or CI). Promoted and unpromoted chromia based catalysts can also be used. For the avoidance of doubt, a chromia based catalyst is one that comprises an effective amount of chromium (Ill) oxide. Such catalysts can also be promoted by the addition of transition metals such as Zn, In, Ga or similar that display +2 and/or +3 oxidation states.

Catalysts comprising Lewis acid metal halides are a preferred group of catalysts for use in the process of the invention for producing 1234yf and/or 1234ze. Example of suitable Lewis acid metal halides include, but are not limited to, Sb(V) halides, such as SbF5.

Alternatively, in the process of the invention for producing a tetrafluoropropene, such as 1234yf and/or 1234ze, when the TFMA is obtained by any means other than the process of the invention described above, suitable catalysts are supported (e.g. on carbon) or unsupported Lewis metal halides, including TaX5, SbX5, SnX4, TiX4, FeCI3, NbX5, VX5, AIX3 (wherein X = F or CI). Example of suitable Lewis acid metal halides include, but are not limited to, Sb(V) halides, such as SbF5.

The process of the invention for producing a tetrafluoropropene such as 1234yf and/or 1234ze can be carried out in any suitable apparatus, such as a static mixer, a tubular reactor, a stirred tank reactor or a stirred vapour-liquid disengagement vessel.

The process of the invention for producing a tetrafluoropropene such as 1234yf and/or 1234ze may be carried out batch-wise or continuously and in the gas or liquid phase.

The process of the invention for producing a tetrafluoropropene such as 1234yf and/or 1234ze may be conducted at a temperature of from about 100 to about 380 °C (e.g. from io about 200 to about 370 °C) and may be carried out at a pressure of from about 5 to about 28 bara (e.g. about 10 to about 25 bara).

In the process of the invention for producing a tetrafluoropropene such as 1234yf and/or 1234ze, the TFMA may be prepared by a process of the invention as described above.

For example, the invention provides a process for producing a tetrafluoropropene such as 1234yf and/or 1234ze, the process comprising (i) converting Z-1233zd to TFMA in the presence of at least one base, wherein the process is conducted in the presence of water, and (ii) contacting the TFMA with hydrogen fluoride (HF) in the presence of a fluorination catalyst to produce 1234yf and/or 1234ze.

Steps (i) and (H) may both be carried out in the liquid phase or both in the vapour phase. Alternatively, step (i) may be carried out in the liquid phase and step (ii) vapour phase, or vice versa.

The process of the invention for producing a tetrafluoropropene such as 1234yf and/or 1234ze may be carried out subsequently to the process of step (i). The TFMA formed in step (i) may be continually removed from the process of step (i), for example via a cold trap, such as a Whitey bomb in a dry ice/acetone bath and purified and/or isolated prior to fluorination in step (ii). The TFMA removed from the process of step (i), for example via a cold trap, may be transferred to a different reaction vessel or zone for conducting the hydrofluorination step (ii). The TMFA may be transferred directly to a different reaction vessel, i.e. may be transferred without being recovered from the reaction or the TFMA may be recovered from the reaction and stored before being transferred to a different reaction vessel. It may in some circumstances be advantageous to purify the TFMA before further reaction. Suitable methods for its purification include, but are not limited to, distillation, phase separation and contacting with adsorbents such as zeolites/aluminosilicates/molecular sieves, carbon, alumina, silica and the like.

By conducting step (i) and (ii) consecutively and in separate reaction zones or vessels, the reagents, temperature, pressure and type of catalyst can be chosen to facilitate the reactions, respectively, as explained below.

For example, step (i) is typically conducted in the absence of a catalyst, whereas a fluorination catalyst as previously described is used for step (ii).

Step (i) is conducted in the absence of HF, whereas a relatively high ratio of HF:TFMA can be used in step (ii). For example, a typical molar ratio of HF:TFMA in step (ii) is generally from about 1:1 to about 100:1 (e.g. about 3:1 to about 50:1).

Still further, higher temperature and/or pressure conditions may be used in the fluorination step (H) compared to step (i). Thus, step (i) may be conducted at a temperature of from about -100 to about 100 °C, such as from about -50 to about 70 °C or -10 to about 50 °C, e.g. from about 0 to about 60 °C or about 20 to about 40 °C, whereas step OD may be conducted at a temperature of from about 100 to about 380 °C (e.g. from about 200 to about 370 °C). Step (i) may be carried out at a pressure of from about 0.1 to about 20 bara (e.g. about 0.5 to about 10 bara), whereas step (ii) may be carried out at a pressure of from about 5 to about 28 bara (e.g. about 10 to about 25 bara).

The invention will now be illustrated by the following non-limiting Examples.

Example 1 -in water

Z-1233zd (20.2 g) in water (19.3 g) was charged to a 100 mL autoclave fitted with a condenser connected to a sample cylinder cooled by dry ice/acetone. The autoclave was stirred and heated to 38°C before adding 40% KOH solution (43.3 g) via syringe pump over 2 h. The mixture was heated for a further 3 h. Gaseous products (7.99 g) were collected in the cooled sample cylinder and analysed by GC showing 95.1 area % TFMA and 4.67 area % Z-1233zd. No organic layer was visible in the aqueous contents of the autoclave.

Example 2 -in water/methanol Z-1233zd (20.4 g) in methanol (19.2 g) was charged to a 100 mL autoclave fitted with a condenser connected to a sample cylinder cooled by dry ice/acetone. The autoclave was stirred and heated to 38°C before adding 40% KOH solution (43.8 g) via syringe pump over 2 h. The mixture was heated for a further 3 h. Gaseous products (10.3 g) were collected in the cooled sample cylinder and analysed by GC showing 93.96 area % TFMA and 5.8 area % Z-1233zd. An organic layer (0.9 g) was isolated from the aqueous contents of the autoclave and analysed by GC showing 98.7 area % 1-methoxy-3,3,3-trifluoropropene.

Example 3 -with phase transfer catalyst Z-1233zd (49.05 g) and Aliquat 336 (1.5 g) were charged to a 100 mL autoclave fitted with a condenser connected to a sample cylinder cooled by dry ice/acetone. The autoclave was stirred and heated to 30°C before adding 40% KOH solution (52.6 g) over 2 h. The mixture was heated for a further 2.5 h. Gaseous products (5.8 g) were collected in the cooled sample cylinder and analysed by GC showing 91.1 area % TFMA and 8.6 area % Z-1233zd. The aqueous contents of the autoclave contained sticky black polymerisation products.

Experiment 4 -Preparation of 1234vf and/or 1234ze from TFMA Liquid phase method: TaF5 (5.5 g, 0.02 mol) was weighed into a 50 mL autoclave in a glovebox. The autoclave was removed from the glovebox and placed in a heating block, then charged with HF (20 g, 1 mol) and TFMA (7.9 g, 0.08 mol). The contents were then stirred at 200 rpm, heated to 50 °C and left for 20 hours. The contents were then transferred to a 500 mL sample cylinder containing 100 mL of water and the vapour analysed via GC. 245fa (96.9 mol%), 1234ze (2.54 mol%), TFMA (0.39 mol%), 245cb (0.17 mol%).

Vapour phase method: 8.1mis (10.3 g) fresh 5.2 % Zn/chromia (chromium (Ill) oxide) catalyst (designated TR1189) of particle size 2-3.65 mm was loaded into a reactor tube and pre-dried at 250°C, at 3 Barg for 24 hours under purge N2=80 mls/min.

The dried catalyst was then activated (Pre-fluorinated) by treatment with hydrogen fluoride: Stage 1: N2 = 80 mls/min HF = 4 mls/min 250°C @ 3 Barg for 24 hours N2= 40 mls/min HF = 4 mls/min 250°C @ 3 Barg for 2 hours N2 = 20 mls/min HF = 4 mls/min 250°C @ 3 Barg for 1 hours N2= 10 mls/min HF = 4 mls/min 250°C @ 3 Barg for 1 hour N2 = 5 mls/min HF = 4 mls/min 300°C @ 3 Barg for 3 hours N2 = 0 mls/min HF = 4 mls/min 300°C @ 3 Barg for 3 hours Stage 2: N2 = 0 mls/min HF = 4 mls/min Temp ramped from 300°C -380°C@25°C/hr Then held for 7 hours at 380°C @ 3 Barg before cooling to 25°C/hr to 150°C.

The results obtained across a range of conditions are shown below: Temp Pressure Barg TFMA HF Ratio Contact time secs TFMA Mol % 1234yf Mol % 1234zeE Mol % 1234zeZ Mol % 245fa Additional °C mls/m in mls/min Mol % By-products Blank 4.0 21 50 2.3 98.41 0.00 0.00 0.00 0.00 8 4.0 24 53 2.2 22 99.08 0.02 0.05 0.11 0.01 7 4.0 25 51 2.1 20 95.50 0-17 2.00 0.99 0.83 9 250 4.0 27 52 1.9 17 4Z26 2.30 15.15 2.97 36.17 13 300 3.9 22 36 1.7 21 6.12 4.67 19.60 4.41 64.00 15 350 4.0 16 50 3.1 18 30.76 3.41 32.96 8.59 22.87 17

Claims

Claims 1. A process for producing TFMA, the process comprising converting Z-1233zd to TFMA in the presence of at least one base, wherein the process is conducted in the presence of water.
2. A process according to claim 1, wherein the at least one base is added to Z-1233zd.
3. A process according to claim 1 or 2, wherein the at least one base is added to an io aqueous solution of Z-1233zd or an aqueous solution of the at least one base is added to Z-1233zd or an aqueous solution of the at least one base is added to an aqueous solution of Z-1233zd.
4. A process for producing TFMA, the process comprising: (i) introducing Z-1233zd to a reactor; (ii) adding at least one base to (i); and (iii) collecting the product TFMA.
5. A process according to claim 4, wherein the Z-1233zd and/or the at least one base are added to the process in the form of an aqueous solution.
6. A process according to any one of the preceding claims, wherein the TFMA product is continually removed from the process.
7. A process according to any one of the preceding claims, wherein the process is conducted in the absence of methanol.
8. A process according to any one of the preceding claims, wherein the process is conducted in the absence of a phase transfer catalyst.
9. A process according to any one of the preceding claims, wherein the process is conducted at a temperature of from about -100 to about 100 °C, such as from about -50 to about 70 °C or -10 to about 50 °C, e.g. from about 0 to about 60 °C or about 20 to about 40 °C.
10. A process according to any one of the preceding claims, wherein the process is conducted at a pressure of from about 0 to about 30 bara, such as from about 0.1 to about 20 bara or from about 0.5 to about 10 bara, e.g. from about 1 to about 5 bara.
11. A process according to any one of the preceding claims, wherein the molar ratio of base:Z-1233zd is from about 10:1 to about 1:10, for example from about 4:1 to about 1:4, for example from about 3:1 to about 2:1.
12. A process for producing TFMA, the process comprising: (i) hydrofluorinating 1,1,1,3,3-pentachloropropane or 1,1,3,3-to tetrachloropropene in the presence or absence of a hydrofluorination catalyst to produce Z-1233zd; and (ii) converting the Z-1233zd obtained in step (i) to TFMA in the presence of at least one base, wherein the process is conducted in the presence of water.
13. A process for preparing a tetrafluoropropene, the process comprising contacting TFMA with hydrogen fluoride (HF) in the presence of a fluorination catalyst to produce a tetrafluoropropene, wherein the TFMA is obtained using a process according to any one of claims 1 to 12.
14. A process for preparing a tetrafluoropropene, the process comprising contacting TFMA with hydrogen fluoride (HF) in the presence of a Lewis acid metal halide catalyst to produce a tetrafluoropropene.
15. A process according to claim 13 or 14, wherein the catalyst is a Sb(V) halide.
16. A process according to any one of claims 13 to 15, wherein the tetrafluoropropene is 1234yf and/or 1234ze.
17. A process according to any one of claims 13 to 16, wherein the molar ratio of HF:TFMA is from about 1:1 to about 100:1 (e.g. about 3:1 to about 50:1).
18. A process according to any one of claims 13 to 17, wherein the process is conducted at a temperature of from about 100 to about 380 °C (e.g. from about 200 to about 370 °C).
19. A process according to any one of claims 13 to 18, wherein the process is conducted at a pressure of from about 5 to about 28 bara (e.g. about 10 to about 25 bara).
20. A process for producing a tetrafluoropropene, the process comprising (i) converting Z-1233zd to TFMA in the presence of at least one base, wherein the process is conducted in the presence of water, and (ii) contacting the TEMA produced in step (i) with hydrogen fluoride (HF) in the presence of a fluorination catalyst to produce a tetrafluoropropene.
21. A process according to claim 20, wherein the tetrafluoropropene is 1234y1 and/or 1234ze.
22. A process according to any one of claims 20 or 21, wherein step (i) is conducted according to any one of claims 1 to 11.
23. A process according to any one of claims 20 to 22, wherein step (h) is conducted according to any of one of claims 13 to 19.Amendments to the claims have been filed as follows. Claims 1. A process for producing at least one tetrafluoropropene, the process comprising: (I) converting Z-1233zd to TFMA in the presence of at least one base, wherein the process is conducted in the presence of water, and (H) contacting the TFMA produced in step (i) with hydrogen fluoride (HF) in the presence of a Lewis acid metal halide catalyst to produce a reaction product comprising at least one tetrafluoropropene. 2. 3. 4. CO 20 5. 6.A process according to claim 1, wherein in step (i) the at least one base is added to Z-1233zd.A process according to claim 1 or 2, wherein in step (i) the at least one base is added to an aqueous solution of Z-1233zd or an aqueous solution of the at least one base is added to Z-1233zd or an aqueous solution of the at least one base is added to an aqueous solution of Z-1233zd.A process according to claim 1 wherein step (i) comprises: a) introducing Z-1233zd to a reactor; b) adding at least one base to (i); and c) removing the product TFMA.A process according to claim 4, wherein the Z-1233zd and/or the at least one base are added to the process in the form of an aqueous solution.A process according to any one of the preceding claims, wherein the TFMA product is continually removed from step (i).7. A process according to any one of the preceding claims, wherein step (i) is conducted in the absence of methanol.8. A process according to any one of the preceding claims, wherein step (i) is conducted in the absence of a phase transfer catalyst.9. A process according to any one of the preceding claims, wherein step (i) is conducted at a temperature of from about -100 to about 100 °C.10. A process according to claim 9, wherein the temperature is from about -50 to about 70 °C or from about -10 to about 50 °C.11. A process according to claim 10, wherein the temperature is from about 0 to about 60 °C or about 20 to about 40 °C.12. A process according to any one of the preceding claims, wherein step (i) is conducted at a pressure of from about 0 to about 30 bara.13. A process according to claim 12, wherein the pressure is from about 0.1 to about bara or from about 0.5 to about 10 bara.14. A process according to claim 13, wherein the pressure is from about 1 to about 5 bara.15. A process according to any one of the preceding claims, wherein the molar ratio of base:Z-1233zd in step (i) is from about 10:1 to about 1:10.16. A process according to claim 15, wherein the ratio of base:Z-1233zd is from about CO 20 4:1 to about 1:4.O 17. A process according to claim 16, wherein the ratio of base:Z-1233zd is from about 3:1 to about 2:1.18. A process according to any one of the preceding claims, wherein the Z-1233zd used in step (i) is prepared by hhydrofluorinating 1,1,1,3,3-pentachloropropane or 1,1,3,3-tetrachloropropene in the presence or absence of a hydrofluorination catalyst to produce Z-1233zd.19. A process according to any one of the preceding claims, wherein in step (ii) the Lewis acid metal halide catalyst comprises Sb(V), Ta(V) or Sn(IV).20. A process according to claim 19, wherein the catalyst in step (ii) is a Sb(V) halide.21. A process according to any one of the preceding claims, wherein the molar ratio of HF:TFMA in step (ii) is from about 1:1 to about 100:1.22. A process according to claim 21, wherein the molar ratio of HF:TFMA is from about 3:1 to about 50:1.CO O23. A process according to any one of the preceding claims, wherein step (ii) is conducted at a temperature of from about 25 to about 380 °C.
24. A process according to claim 23, wherein the temperature is from about 50 to about 350 °C.
25. A process according to any one of the preceding claims, wherein step (ii) is conducted at a pressure of from about 5 to about 28 bara.
26. A process according to claim 25, wherein the pressure is from about 10 to about 25 bara.
27. A process according to any one of the preceding claims, wherein step (ii) is conducted in the liquid phase.
28. A process according to any one of the preceding claims, wherein the TFMA produced in step (i) is passed directly to step (ii).
29. A process according to any one of claims 1 to 28, wherein the TFMA produced in step (i) is purified before passing to step (ii).
30. A process according to any one of the preceding claims, wherein step (i) and step (ii) are conducted in the liquid phase.
31. A process according to any one of the preceding claims, wherein the at least one tetrafluoropropene is or comprises 1234yf and/or 1234ze.