Method for producing 2,3,3,3-tetrafluoropropene

Patent metadata

Field	Value
Publication number	US-10047023-B2
Application number	US-201615190535-A
Country	US
Kind code	B2
Filing date	Jun 23, 2016
Priority date	Jul 12, 2013
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

This invention provides a method for producing 2,3,3,3-tetrafluoropropene or 2-chloro-1,1,1,2-tetrafluoropropane, which is a precursor of 2,3,3,3-tetrafluoropropene, in two or three reaction steps, using at least one chlorine-containing compound selected from the group consisting of 1,1,1,2,3-pentachloropropane, 2,3-dichloro-1,1,1-trifluoropropane, and 1,1,2,3-tetrachloropropene as a starting material, the reaction products of at least two of the steps being supplied to the same distillation apparatus to subject the products to a separation operation simultaneously. With this method, 2,3,3,3-tetrafluoropropene or 2-chloro-1,1,1,2-tetrafluoropropane, which is a precursor of 2,3,3,3-tetrafluoropropene, can be efficiently produced with reduced energy and equipment costs in an economically advantageous manner.

First claim

The invention claimed is:

1. A method for producing 2,3,3,3-tetrafluoropropene, comprising the reaction steps of:
(1) obtaining 2-chloro-3,3,3-trifluoropropene by reacting a fluorinating agent with at least one chlorine-containing compound selected from the group consisting of 1,1,1,2,3-pentachloropropane, 2,3-dichloro-1,1,1-trifluoropropane, and 1,1,2,3-tetrachloropropene;
(2) obtaining 2-chloro-1,1,1,2-tetrafluoropropane by adding hydrogen fluoride to the 2-chloro-3,3,3-trifluoropropene, wherein the reaction is conducted in gas phase; and
(3) obtaining 2,3,3,3-tetrafluoropropene by dehydrochlorination of the 2-chloro-1,1,1,2-tetrafluoropropane,
wherein reaction step (1) is performed in a first reactor, reaction step (2) is performed in a second reactor, and reaction step (3) is performed in a third reactor,
wherein the first reactor, the second reactor, and the third reactor each comprise an outlet,
the method further comprising the step of supplying the products obtained from the outlet of the first reactor, the products obtained from the outlet of the second reactor, and the products obtained from the outlet of the third reactor to a single distillation apparatus to separate the products into a hydrogen chloride-containing fraction and a fraction free of hydrogen chloride which comprises 2-chloro-1,1,1,2-tetrafluoropropane as a major component,
wherein at least two products selected from the group consisting of the products obtained from the outlet of the first reactor, the products obtained from the outlet of the second reactor, and the products obtained from the outlet of the third reactor are mixed prior to being supplied to the single distillation apparatus.

2. The method for producing 2,3,3,3-tetrafluoropropene according to claim 1 , wherein reaction step (1) is performed by reacting anhydrous hydrogen fluoride with at least one chlorine-containing compound selected from the group consisting of 1,1,1,2,3-pentachloropropane, 2,3-dichloro- 1,1,1-trifluoropropane, and 1,1,2,3-tetrachloropropene in a gas phase in the presence of a fluorination catalyst while heating.

3. The method for producing 2,3,3,3-tetrafluoropropene according to claim 1 , further comprising the step of removing hydrogen chloride from the hydrogen chloride-containing fraction.

4. The method for producing 2,3,3,3-tetrafluoropropene according to claim 3 , further comprising the step of recycling all or part of the fraction from which hydrogen chloride has been removed to at least one of the reaction steps.

5. The method for producing 2,3,3,3-tetrafluoropropene according to claim 1 , further comprising the step of collecting 2,3,3,3-tetrafluoropropene from the hydrogen chloride-containing fraction and/or the fraction free of hydrogen chloride.

6. The method for producing 2,3,3,3-tetrafluoropropene according to claim 1 , further comprising the step of recycling all or part of the fraction free of hydrogen chloride to at least one of the reaction steps.

Assignees

• Daikin Ind Ltd

Inventors

• Chaki Takehiro
• Takahashi Kazuhiro
• Takakuwa Tatsuya

Classifications

• C07C17/383

  by distillation · CPC title

• C07C17/25 Primary

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

• C07C17/087 Primary

  to unsaturated halogenated hydrocarbons · CPC title

• C07C17/206

  the other compound being HX · CPC title

• Y02P20/582

  Recycling of unreacted starting or intermediate materials · CPC title