Process for the production of chlorinated propenes

Patent metadata

Field	Value
Publication number	US-9475739-B2
Application number	US-201214236286-A
Country	US
Kind code	B2
Filing date	Aug 1, 2012
Priority date	Aug 7, 2011
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

Processes for the production of chlorinated propenes are provided. The present processes make use of a feedstock comprising 1,2,3-trichloropropane and chlorinates the 1,1,2,3-tetrachloropropane generated by the process prior to a dehydrochlorination step. Production of the less desirable pentachloropropane isomer, 1,1,2,3,3-pentachloropropane, is thus minimized. The present processes provide better reaction yield as compared to conventional processes that require dehydrochlorination of 1,1,2,3-tetrachloropropane prior to chlorinating the same. The present process can also generate anhydrous HCl as a byproduct that can be removed from the process and used as a feedstock for other processes, while limiting the production of waste water, thus providing further time and cost savings.

First claim

The invention claimed is:

1. A process for the production of chlorinated propenes from a feedstream comprising 1,2,3-trichloropropane, comprising at least one chlorination step and at least one dehydrochlorination step, wherein 1,2,2,3-tetrachloropropane produced by the process is recycled and/or further reacted.

2. The process of claim 1 , wherein the chlorination step produces a mixture comprising tetrachloropropanes and pentachloropropanes.

3. The process of claim 2 , wherein the mixture is separated to provide a stream comprising the 1,2,2,3-tetrachloropropane.

4. The process of claim 3 , wherein the 1,2,2,3-tetrachloropropane stream is recycled to the first chlorination step.

5. The process of claim 3 , wherein the 1,2,2,3-tetrachloropropane stream is chlorinated in a second chlorination step to provide 1,1,2,2,3-pentachloropropane.

6. The process of claim 3 , wherein the separation further provides a stream of unreacted 1,2,3-trichloropropane that is recycled to a chlorination step.

7. The process of claim 3 , wherein the separation further provides a stream of HCl and a stream comprising unreacted Cl 2 , wherein the HCl is recovered from the process as anhydrous HCl and the Cl 2 is recycled.

8. The process of claim 3 , wherein the separation further provides a stream comprising 1,1,2,3-tetrachloropropane and a stream comprising pentachloropropane isomers and heavier byproducts.

9. The process of claim 8 , wherein the stream comprising 1,1,2,3-tetrachloropropane is dehydrochlorinated to produce a stream comprising trichloropropene, and the trichloropropene stream is chlorinated to produce a stream comprising 1,1,1,2,3-pentachloropropane and 1,1,2,2,3-pentachloropropane.

10. The process of claim 1 , wherein the at least one chlorination step is carried out in the presence of a free radical initiator comprising, azobisisobutyronitrile, 1,1′-azobis(cyclohexanecarbonitrile), 2,2′-azobis(2,4-dimethyl valeronitrile), and dimethyl 2,2′-azobis(2-methylpropionate), or a combination of these.

11. The process of claim 1 , wherein the at least one dehydrochlorination is carried out in the presence of dehydrochlorinating catalyst comprising iron, ferric chloride, aluminum chloride, or a combination of these.

12. The process of claim 3 , wherein the remainder of the mixture is dehydrochlorinated to provide a stream comprising 1,1,2,3-tetrachloropropene, 2,3,3,-tetrachloropropane, HCl and unreacted pentachloropropanes.

13. The process of claim 12 , wherein the unreacted pentachloropropanes are dehydrochlorinated to provide a mixture comprising 1,1,2,3-tetrachloropropene.

14. The process of claim 3 , wherein the 1,2,2,3-tetrachloropropane is recycled to a dehydrochlorination step to produce 1,2,3-trichloropropene, and the 1,2,3-trichloropropene is chlorinated to produce 1,1,2,2,3-pentachloropropane.

Assignees

• Tirtowidjojo Max M
• Fish Barry B
• Laitar David S
• Blue Cube Ip Llc

Inventors

• Tirtowidjojo Max M
• Fish Barry B
• Laitar David S

Classifications

• C07C17/23

  by dehalogenation · CPC title

• C07C17/25

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

• C07C17/06 Primary

  combined with replacement of hydrogen atoms by halogens · CPC title

• C07C17/20 Primary

  of halogen atoms by other halogen atoms · CPC title

• C07C17/093

  by replacement by halogens · CPC title