Process for the manufacture of fluorinated olefins

Patent metadata

Field	Value
Publication number	US-9994503-B2
Application number	US-201615090027-A
Country	US
Kind code	B2
Filing date	Apr 4, 2016
Priority date	Oct 27, 2006
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

Abstract

A method for producing 1,1,1,2-tetrafluoropropene and/or 1,1,1,2,3-pentafluoropropene using a single set of four unit operations, the unit operations being (1) hydrogenation of a starting material comprising hexafluoropropene and optionally recycled 1,1,1,2,3-pentafluoropropene; (2) separation of the desired intermediate hydrofluoroalkane, such as 1,1,1,2,3,3-hexafluoropropane and/or 1,1,1,2,3-pentafluoropropane; (3) dehydrofluorination of the intermediate hydrofluoroalkane to produce the desired 1,1,1,2-tetrafluoropropene and/or 1,1,1,2,3-pentafluoropropene, followed by another separation to isolate the desired product and, optionally, recycle of the 1,1,1,2,3-pentafluoropropene.

First claim

What is claimed is:

1. A method for producing 1,1,1,2-tetrafluoropropene comprising:
a. hydrogenating a starting material stream comprising hexafluoropropylene by contacting said starting material stream with a reducing agent in a hydrogenation reactor to produce an intermediate stream comprising 1,1,1,2,3-pentafluoropropane;
b. dehydrofluorinating said 1,1,1,2,3-pentafluoropropane in a dehydrofluorination reactor to produce a product stream comprising 1,1,1,2-tetrafluoropropene.

2. The method of claim 1 wherein at least a portion of said hexafluoropropylene reacts with said reducing agent to produce 1,1,1,2,3,3-hexafluoropropane and at least a portion of said 1,1,1,2,3,3-hexafluoropropane reacts with said reducing agent to produce at least a portion of said 1,1,1,2,3-pentafluoropropane.

3. The method of claim 2 wherein said intermediate stream further comprises 1,1,1,2,3,3-hexafluoropropane.

4. The method of claim 3 wherein said intermediate stream is separated into an intermediate recycle stream rich in 1,1,1,2,3,3-hexafluoropropane and said intermediate recycle stream is introduced into the hydrogenation reactor wherein at least a portion of said recycled 1,1,1,2,3,3-hexafluoropropane is hydrogenated to form 1,1,1,2,3-pentafluoropropane.

5. The method of claim 3 further comprising:
c. dehydrofluorinating said 1,1,1,2,3,3-hexafluoropropane in said dehydrofluorination reactor to form 1,1,1,2,3-pentafluoropropene.

6. The method of claim 5 wherein at least a portion of said 1,1,1,2,3-pentafluoropropene is recycled and is introduced at step (a) wherein at least a portion of said recycled 1,1,1,2,3-pentafluoropropene is hydrogenated to form 1,1,1,2,3-pentafluoropropane.

7. The method of claim 5 wherein steps (b) and (c) are performed concurrently in the dehydrofluorination reactor, and said product stream further comprises said 1,1,1,2,3-pentafluoropropene.

8. The method of claim 7 wherein said product stream is separated into a final product stream rich in said 1,1,1,2-tetrafluoropropene and a product recycle stream rich in said 1,1,1,2,3-pentafluoropropene, and introducing said product recycle stream into the hydrogenation reactor, wherein at least a portion of said 1,1,1,2,3-pentafluoropropene is hydrogenated to form a portion of said intermediate stream.

9. The method of claim 8 wherein said intermediate stream is separated into an intermediate recycle stream rich in 1,1,1,2,3,3-hexafluoropropane and said intermediate recycle stream is introduced into the hydrogenation reactor wherein at least a portion of said recycled 1,1,1,2,3,3-hexafluoropropane is hydrogenated to form 1,1,1,2,3-pentafluoropropane.

10. A system for producing at least one fluorinated olefin comprising:
a. a hydrogenation reactor;
b. a starting material feed stream fluidly connected to said hydrogenation reactor, wherein said starting material feed stream comprises hexafluoropropylene;
c. one or more intermediate streams fluidly connected to said hydrogenation reactor;
d. a first separator fluidly connected to said one or more intermediate streams;
e. one or more post separator streams fluidly connected to said first separator;
f. optionally, a first recycle stream fluidly connected to said first separator and said hydrogenation reactor;
g. a dehydrohalogenation reactor fluidly connected to at least one of said post separator streams;
h. a product stream fluidly connected to said dehydrohalogenation reactor;
i. a second separator fluidly connected to said product stream;
j. a second recycle stream fluidly connected to said second separator and said hydrogenation reactor; and
k. a final product stream fluidly connected to said second separator, wherein said final product stream is rich in 1,1,1,2-tetrafluoropropene or 1,1,1,2,3-pentafluoropropene.

11. The system of claim 10 wherein said final product stream is rich in 1,1,1,2-tetrafluoropropene and said second recycle stream is rich in said 1,1,1,2,3-pentafluoropropene.

Assignees

• Honeywell Int Inc

Inventors

• Chiu Yuon
• Cottrell Stephen A
• Tung Hsueh Sung
• Kopkalli Haluk
• Cerri Gustavo

Classifications

• C07C17/38

  Separation; Purification; Stabilisation; Use of additives · CPC title

• B01J2219/0072

  Organic compounds · CPC title

• C07C17/25 Primary

  by splitting-off hydrogen halides from halogenated hydrocarbons · CPC title

• B01J2219/00759

  Purification of compounds synthesised · CPC title

• B01J2219/0059

  Sequential processes · CPC title