Dehydrohalogenation of hydrochlorofluorocarbons

Patent metadata

Field	Value
Publication number	US-12247000-B2
Application number	US-202318479882-A
Country	US
Kind code	B2
Filing date	Oct 3, 2023
Priority date	Sep 11, 2015
Publication date	Mar 11, 2025
Grant date	Mar 11, 2025

Abstract

A dehydrohalogenation product includes a hydrochlorofluorocarbon mixture of a fluoroolefin of formula RCX=CZQ and a halofluoroalkane of formula RCXYCZQT. R is a perfluorinated alkyl group and X, Z, and Q are independently H or halogen. One of Y and T is H and the other is Cl, Br, or I. About 80% or greater of the hydrochlorofluorocarbon mixture is the fluoroolefin. The dehydrohalogenation product also includes a caustic agent and a solvent. In some embodiments, the dehydrohalogenation product is free of any catalyst, including any phase transfer catalyst.

First claim

What is claimed is:

1. A dehydrochlorination process comprising vigorously contacting a chlorofluoroalkane of formula RCXYCZQT in an aqueous solvent comprising NaOH in a molar ratio of about 0.5 to about 2.0 of NaOH:chlorofluoroalkane, in the absence of any additional phase transfer catalyst, at a temperature in the range of about 30° C. to about 80° C. to produce a product comprising a fluoroolefin of formula RCX=CZQ, wherein R is a perfluorinated alkyl group and X, Z, and Q are independently H or fluorine, and one of Y and T is H and the other is Cl, wherein the conversion by the dehydrochlorination process is at least 95% of the maximum based on a starting ratio of NaOH and chlorofluoroalkane.

2. The dehydrochlorination process of claim 1 , wherein the conversion by the dehydrochlorination process is at least 98% of the maximum based on the starting ratio of NaOH and chlorofluoroalkane.

3. The dehydrochlorination process of claim 1 , wherein RCX=CZQ comprises one of CF 3 CF═CH 2 , CF 3 CH═CHF, and CF 3 CCl═CH 2 .

4. The dehydrochlorination process of claim 3 , wherein RCX=CZQ comprises CF 3 CF═CH 2 .

5. The dehydrochlorination process of claim 1 , wherein the aqueous solvent further comprises a co-solvent.

6. The dehydrochlorination process of claim 1 , wherein the dehydrohalogenation is conducted for about 1 to 120 minutes.

7. The dehydrochlorination process of claim 6 , wherein the dehydrohalogenation is conducted for about 10 to about 45 minutes.

8. The dehydrochlorination process of claim 1 , wherein the fluoroolefin is a chlorofluoroolefin.

9. The process of claim 1 , wherein the vigorous contacting involves agitation.

10. The process of claim 1 , wherein the vigorous contacting involves a mixing power at a horsepower in the range of 0.5 to 40 per 1000 gallons.

11. The process of claim 10 , wherein the mixing power is at a horsepower in the range of 1.2 to 40 per 1000 gallons.

12. The process of claim 1 , wherein the temperature is in the range of about 50 to about 80° C.

13. The process of claim 1 , wherein the aqueous solvent is about 12 wt % NaOH.

14. The process of claim 1 , wherein the molar ratio of NaOH:chlorofluoroalkane is sufficient to convert at least 99% of the chlorofluoroalkane.

15. A composition comprising:
a hydrochlorofluorocarbon mixture comprising:
a fluoroolefin of formula RCX=CZQ, wherein R is a perfluorinated alkyl group and X, Z, and Q are independently H or fluorine; and
a chlorofluoroalkane of formula RCXYCZQT, wherein one of Y and T is H and the other is Cl; and

an aqueous solvent comprising NaOH in a molar ratio of 0.5 to 2.0 of NaOH:hydrochlorofluorocarbon mixture.

16. The composition of claim 15 , wherein RCX=CZQ comprises one of CF 3 CF═CH 2 , CF 3 CH═CHF, and CF 3 CCl═CH 2 .

17. The composition of claim 16 , wherein RCX=CZQ comprises CF 3 CF═CH 2 .

18. The composition of claim 15 , the aqueous solvent further comprising a co-solvent.

19. The composition of claim 15 , wherein the NaOH is about 12 wt % in aqueous solvent.

20. The composition of claim 15 , wherein the composition is free of any additional phase transfer catalyst and wherein the molar ratio of NaOH:chlorofluoroalkane is sufficient to convert at least 95% of the chlorofluoroalkane based on a starting ratio of NaOH and chlorofluoroalkane.

Assignees

• Chemours Co Fc Llc

Inventors

• Sun Xuehui
• Krause Karl

Classifications

• C07C17/20

  of halogen atoms by other halogen atoms · CPC title

• C07C21/18

  containing fluorine · CPC title

• C09K2205/122

  Halogenated hydrocarbons · CPC title

• C09K2205/126

  Unsaturated fluorinated hydrocarbons · CPC title

• A62D1/0071

  Foams · CPC title