# US 2019/0169098 A1 · Process for the preparation of 3,3,3-trifluopropene

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- Number: US 2019/0169098 A1
- Document ID: US20190169098A1
- Status: Published application
- Kind: A1
- Application number: 15/745,460
- Filed: 2016-07-14
- Published: 2019-06-06
- Earliest claimed: 2015-07-17
- Assignees: Mexichem Fluor S.A. De C.V.
- Applicants: Mexichem Fluor S.A. De C.V.
- Inventors: EMMA J HODGSON; CLAIRE ELIZABETH McGUINNESS; CLIVE ROBERT GIDDIS; JAMES HENRY MURRAY; CLARE MARY SKAE; GARY LLOYD
- Web page: https://patentgrep.com/patent/US20190169098A1

## CPC

- C07C 17/25: by splitting-off hydrogen halides from halogenated hydrocarbons
- C07C 17/07: by addition of hydrogen halides
- C07C 17/35: by reactions not affecting the number of carbon or of halogen atoms in the reaction
- C09K 5/04: the change of state being from liquid to vapour or vice versa
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

The present invention provides a process for preparing 3,3,3-trifluoropropene (1243zf), the process comprising: (a)fluorinating CCI3CH2CH2CI (250fb) to produce a reaction product comprising CF3CH2CH2CI (253fb) in the liquid phase in a first reactor, using HF as the fluorinating agent; and (b)(i) dehydrohalogenating 253fb to produce 1243zf in the vapour phase in the present of a catalyst in a second reactor; or (b)(ii) dehydrohalogenating 253fb to produce 1243zf in a second reactor, wherein the reaction product comprising 253fb produced in step (a) has subjected to one or more purification steps before step (b). The present invention also provides an azeotropic or near-azeotropic composition comprising HF and 253fb.

## Claims

### Claim 1

A process for preparing 3,3,3-trifluoropropene (1243zf ), the process comprising:
(a) fluorinating CCl3CH2CH2Cl (250fb) to produce a reaction product comprising CF3CH2CH2Cl (253fb) in the liquid phase in a first reactor, using HF as the fluorinating agent; and
(b) dehydrohalogenadrig 253fb to produce 1243zf in the vapour phase in the presence of a catalyst in a second reactor.

### Claim 2 (depends on 1)

A process according to claim 1, wherein the catalyst used in step (b) comprises activated carbon, alumina and/or chromia or zinc/chromia.

### Claim 3 (depends on 2)

A process according to claim 2, wherein the catalyst used in step (b) is activated carbon, Pd/carbon, Pt/carbon, Au/carbon, Pd/alumina, Ni/alumina, Pt/alumina, Cr/alumina or Zn/chromia.

### Claim 4 (depends on 1)

A process according to claim 1, wherein the catalyst used in step (b) is pre-fluorinated.

### Claim 5 (depends on 1)

A process according to claim 1, wherein step (b) is conducted at a temperature from about 250° C. to about 350° C.

### Claim 6 (depends on 5)

A process according to claim 5, wherein step (b) is conducted at a temperature of from about 250° C. to about 300° C.

### Claim 7 (depends on 2)

A process according to claim 2, wherein the catalyst used in step (b) comprises activated carbon and the process of step (b) is conducted at a temperature from about 250° C. to about 300° C.

### Claim 8 (depends on 4)

A process according to claim 4, wherein the catalyst used in step (b) is a pre-fluorinated Zn/chromia catalyst and the process of step (b) is conducted at a temperature from about 250° C. to about 350° C.

### Claim 9 (depends on 1)

A process according to claim 1, wherein in step (b) HF is co-fed with 253fb.

### Claim 10 (depends on 1)

A process according to claim 1, wherein the reaction product comprising 253fb produced in step (a) is subjected to one or more purification steps before step (b).

### Claim 11

A process for preparing 3,3,3-trifluoropropene (1243zf), the process comprising:
(a) fluorinating CCl3CH2CH2Cl (250fb) to produce a reaction product comprising CF3CH2CH2Cl (253fb) in the liquid phase in a first reactor, using HF as the fluorinating agent; and
(b) dehydrohalogenating 253fb to produce 1243zf in a second reactor;
wherein the reaction product comprising 253fb produced in step (a) is subjected to one or more purification steps before step (b).

### Claim 12 (depends on 9)

A process according to claim 9, wherein the purification steps comprise subjecting product stream from step (a) to distillation to remove or reduce the concentration of HCl and then phase separation to separate HF from the product stream comprising 253fb and optionally passing the stream comprising 253fb through a H2SO4 scrubber.

### Claim 13 (depends on 11)

A process according claim 11, wherein HF is recycled to step (a).

### Claim 14 (depends on 1)

A process according to claim 1, wherein the first reactor is connected to a rectifying column.

### Claim 15 (depends on 13)

A process according to claim 13, wherein at least part of the HF is introduced into the first reactor via the top of the rectifying column.

### Claim 16 (depends on 11)

A process according to claim 11, wherein unused HF is separated from the reaction product produced in step (a) and recycled to the first reactor.

### Claim 17 (depends on 1)

A process according to claim 1, wherein step (a) is conducted at a temperature of from about 40 to about 70° C.

### Claim 18 (depends on 1)

A process according to claim 1, wherein step (a) is conducted at a pressure of from about 200 kPa to about 700 kPa.

### Claim 19 (depends on 1)

A process according to claim 1, wherein step (a) is conducted in the presence of a polymerisation inhibitor and/or retarder.

### Claim 20 (depends on 19)

A process according to claim 19, wherein the polymerisation inhibitor and/or retarder is selected from the group consisting of: cyclic ketone or quinone-based aromatic compounds, nitro- or nitrogen-containing compounds, and sulphur-containing compounds.

### Claim 21 (depends on 20)

A process according to claim 20, wherein the cyclic ketone is cyclobutanone or cyclohexanone or a mixture thereof.

### Claim 22 (depends on 1)

A process according to claim 1, wherein step (a) is conducted in the presence of a Lewis acid catalyst.

### Claim 23 (depends on 22)

A process according to claim 22, wherein the catalyst is SnCl4.

### Claim 24 (depends on 1)

A process according to claim 1, wherein step (a) is a semi-continuous reaction.

### Claim 25 (depends on 1)

A process according to claim 1, wherein the process in step (b) is continuous.

### Claim 26

An azeotropic or near-azeotropic composition comprising HF and 253fb.

### Claim 27

An azeotropic or near-azeotropic composition consisting of HF and 253fb.

### Claim 28 (depends on 27)

An azeotropic or near-azeotropic composition according to claim 27 consisting of from about 70 mol % to about 85 mol % HF and from 30 mol % to 15 mol % 253fb.

### Claim 29

A composition that is azeotropic at 70° C. and 600 kPa, which consisting of about 75 mol % HF and about 25 mol % 253fb.

### Claim 30

(canceled)