Process for the manufacture of 2,3,3,3-tetrafluoropropene

Patent metadata

Field	Value
Publication number	US-9296670-B2
Application number	US-201314377727-A
Country	US
Kind code	B2
Filing date	Feb 8, 2013
Priority date	Feb 10, 2012
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

A method for forming 2,3,3,3-tetrafluoropropene (HFO-1234yf) comprising providing a dehydrochlorination starting material having relatively low concentrations of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), especially and preferable less than about 8.0% when the dehydrochlorination reaction utilizes no substantial amount of catalyst or catalyst comprising austenitic nickel-based materials.

First claim

What is claimed is:

1. A process for reducing the concentration of 2-chloro-3,3,3-trifluoropropene in a composition comprised of 2-chloro-1,1,1,2-tetrafluoropropane and 2-chloro-3,3,3-trifluoropropene which comprises conducting a process selected from
(a) photochlorinating the composition to form 1,2,2-trichloro-3,3,3-trifluoropropane in the presence of at least one chlorination agent and separating the 2-chloro-1,1,1,2-tetrafluoropropane from the 1,2,2-trichloro-3,3,3-trifluoropropane;
(b) passing the composition over a fixed bed of solid adsorbents selected from activated carbons and zeolites or molecular sieves, and collecting the 2-chloro-1,1,1,2-tetrafluoropropane from the fixed bed of solid adsorbents; and
(c) mixing said composition with liquid hydrofluoric acid to form a mixture comprised of 2-chloro-1,1,1,2-tetrafluoropropane and 2-chloro-3,3,3-trifluoropropene and HF, said HF present in the mixture is less than about 10% by weight; distilling the mixture and collecting the distilled product substantially free of 2-chloro-3,3,3-trichloropropene and purer in 2-chloro-1,1,1,2-tetrafluoropropane.

2. The process according to claim 1 where the composition is photochlorinated.

3. The process according to claim 2 where photochlorinating comprises exposing the composition to radiation in the presence of said at least one chlorination agent.

4. The process according to claim 1 wherein the photochlorinating is carried out in the vapor phase at a temperature ranging from about −20 C to about 200 C.

5. The process according to claim 1 wherein 2-chloro-1,1,1,2-tetrafluoropropane is separated from 2-chloro-3,3,-trifluoropropene utilizing activated carbon.

6. The process according to claim 1 wherein 2-chloro-1,1,1,2-tetrafluoropropane is separated from 2-chloro-3,3,-trifluoropropene utilizing molecular sieves or zeolites.

7. The process according to claim 6 wherein the pores of the molecular sieves or zeolites ranges from about 3 Angstroms to about 10 Angstroms.

8. The process according to claim 1 comprising mixing said composition with liquid hydrofluoric acid to form a mixture comprised of 2-chloro-1,1,1,2-tetrafluoropropane and 2-chloro-3,3,3-trifluoropropene and HF, said HF is present in the mixture in less than about 10% by weight; and distilling the mixture; and collecting the distilled product substantially free of 2-chloro-3,3,3-trichloropropene and purer in 2-chloro-1,1,1,2-tetrafluoropropane.

9. A process for preparing 2,3,3,3-tetrafluoropropene comprising:
(i) subjecting a first composition comprising a 2-chloro-1,1,1,2-tetrafluoropropane and 2-chloro-3,3,3-trifluoropropene to purification process that reduces the concentration of 2-chloro-3,3,3-trifluoropropene so that the composition is substantially free of 2-chloro-3,3,3-trifluoropropene; and
(ii) contacting said purified composition with a dehydrochlorination catalyst to produce a final composition comprising 2,3,3,3-tetrafluoropropene, wherein said purification process is selected from
(a) photochlorinating the first composition to form 1,2,2-trichloro-3,3,3-trifluoropropane in the presence of at least one chlorination agent and separating the 2-chloro-1,1,1,2-tetrafluoropropane from the 1,2,2-trichloro-3,3,3-trifluoropropane;
(b) passing the first composition over a fixed bed of solid adsorbents selected from activated carbon and zeolites or molecular sieves, and collecting the 2-chloro-1,1,1,2-tetrafluoropropane from the of activated carbon, zeolites or molecular sieves; and
(c) mixing said first composition with liquid hydrofluoric acid to form a mixture comprised of 2 chloro-1,1,1,2-tetrafluoropropane and 2-chloro-3,3,3-trifluoropropene and HF, said HF present in the mixture is less than about 10% by weight; and feeding the mixture and collecting the distilled product substantially free of 2-chloro-3,3,3-trichloropropene and purer in 2-chloro-1,1,1,2-tetrafluoropropane.

10. A process for preparing 2,3,3,3-tetrafluoropropene comprising:
(i) providing a first composition including a compound of Formulae I, II, or III:
CX 2 ═CCl—CH 2 X  (I);

CX 3 —CCl═CH 2   (II); or

CX 3 —CHCl—CH 2 X  (III)

wherein X is independently selected from F, Cl, Br, and I, provided that at least one X is not fluorine;
(ii) contacting the first composition with a first fluorinating agent to produce a first intermediate composition including 2-chloro-3,3,3-trifluoropropene and a first chlorine-containing byproduct;
(iii) contacting the first intermediate composition with a second fluorinating agent to produce a second intermediate composition including 2-chloro-1,1,1,2-tetrafluoropropane and 2-chloro-3,3,3-trifluoropropene;
(iv) reducing the concentration of 2-chloro-3,3,3-trifluoropropene in the second intermediate composition to produce a third intermediate composition comprising 2-chloro-1,1,1,2-tetrafluoropropane that is substantially free of 2-chloro-3,3,3-trifluoropropene; and
(v) dehydrochlorinating at least a portion of the third intermediate composition comprising 2-chloro-1,1,1,2-tetrafluoropropane to produce a reaction product including 2,3,3,3-tetrafluoropropene, wherein the second intermediate composition comprised of 2-chloro-1,1,1,2-tetrafluoropropene is made substantially free of 2-chloro-3,3,3-trifluoropropene by subjecting the second intermediate composition to a process selected from
(a) photochlorinating the second intermediate composition to form 1,2,2,-trichloro-3,3,3-trifluoropropane in the presence of at least one chlorination agent and separating the 2-chloro-1,1,1,2-tetrafluoropropane from the 1,2,2,-trichloro-3,3,3-trifluoropropane;
(b) passing the second intermediate composition over a fixed bed of solid adsorbents selected from activated carbons and zeolites or molecular sieves and collecting the 2-chloro-1,1,1,2-tetrafluoropropane from the activated carbon, zeolites or molecular sieves; and
(c) mixing said second intermediate composition with liquid hydrofluoric acid to form a mixture comprised of 2-chloro-1,1,1,2-tetrafluoropropane and 2-chloro-3,3,3-trifluoropropene and HF, said HF present in the mixture is less than about 10% by weight; distilling the mixture; and collecting the distilled product substantially free of 2-chloro-3,3,3-trichloropropene and purer in 2-chloro-1,1,1,2-tetrafluoropropane.

11. The process according to claim 9 wherein the third intermediate composition comprises 2-chloro-3,3,3-trifluoropropene in an amount less than about 20 wt %.

12. The process according to claim 10 wherein the third intermediate composition comprises 2-chloro-3,3,3-trifluoropropene in an amount less than about 5 wt %.

13. A process of preparing 2,3,3,3-tetrafluoropropene that is substantially free of 3,3,3-trifluoropropyne comprising:
(i) Providing a first composition comprising a 2-chloro-1,1,1,2-tetrafluoropropane that is substantially free of 2-chloro-3,3,3-trifluoropropene; and
(ii) contacting said first composition with a dehydrochlorination catalyst to produce a final composition comprising 2,3,3,3-tetrafluoropropene, said final composition being substantially free of 3,3,3-trifluoropropyne.

14. A process for producing 2,3,3,3-tetrafluoropropene that is substantially free of 3,3,3-trifluoropropyne comprising:
(i) providing a first composition including a compound of Formulae I, II, or III:
CX 2 ═CCl—CH 2 X  (I);

CX 3 —CCl═CH 2   (II); or

CX 3 —CHCl—CH 2 X  (III)

wherein X is independently selected from F, Cl, Br, and I, provided that at least one X is not fluorine;
(ii) contacting the first composition with a first fluorinating agent to produce a first intermediate composition including 2-chloro-3,3,3-trifluoroprope

Assignees

• Honeywell Int Inc
• Chemours Co Fc Llc

Inventors

• Wang Haiyou
• Tung Hsueh S
• Kopkalli Haluk
• Chiu Yuon
• Cerri Gustavo
• Ball Jeffrey
• Da Prato Philip L
• Sun Xuehui
• Nappa Mario Joseph

Classifications

• Y02P20/582

  Recycling of unreacted starting or intermediate materials · CPC title

• C07C17/389

  by adsorption on solids · CPC title

• B01J27/08

  Halides · CPC title

• C07C17/06 Primary

  combined with replacement of hydrogen atoms by halogens · CPC title

• C07C17/087

  to unsaturated halogenated hydrocarbons · CPC title