Process for producing 1,1,1,3,3-pentafluoropropane

• US 6,472,573 B1
• Filed: 08/02/2000
• Issued: 10/29/2002
• Est. Priority Date: 03/23/1998
• Status: Expired due to Term

• Current Assignee: Daikin Industries Ltd
• Original Assignee: Daikin Industries Ltd
• Inventors: Yamamoto, Akinori, Shibata, Noriaki, Shibanuma, Takashi, Nakada, Tatsuo
• Primary Examiner(s): SIEGEL, ALAN M
• Application Number:
  US09/601,511
• Time in Patent Office: 818 Days
• Field of Search: 570/164, 570/165, 570/166, 570/167, 570/168, 570/169
• US Class Current: 570/164
• CPC Class Codes: C07C 17/087 to unsaturated halogenated hydrocarbons
• CPC Class Codes: C07C 17/206 the other compound being HX
• CPC Class Codes: C07C 17/38 Separation; Purification; Stabilisation; Use of additives
• CPC Class Codes: C07C 19/08 containing fluorine
• CPC Class Codes: C07C 21/18 containing fluorine

Abstract

A method of preparation for 1,1,1,3,3-pentafluoropropane (HFC-245fa) wherein the first process gives mainly 1,3,3,3-tetrafluoropropene (1234ze) by reacting 1-chloro-3, 3,3,-trifluoropropene (1233zd) with hydrogen fluoride in the gas phase and subsequently the second process gives 1,1,1,3,3-pentafluoropropane (HFC-245fa) by reacting 1,3,3,3-tetrafluoropropene (1234ze), separated as a component that does not contain hydrogen chloride from crude products obtained by the first process, with hydrogen fluoride in the gas phase. To provide a process that is capable of preparing economically HFC-245fa which does not require the separation of HFC-245fa and 1233zd.

Claims

1. A preparation method for 1,1,1,3,3-pentafluoropropane comprising:

a first process which gives a reaction mixture consisting mainly of 1,3,3,3-tetrafluoropropene by reacting 1-chloro-3,3,3-trifluoropropene with hydrogen fluoride in a gas phase;

a subsequent process of removing HCl and 1-chloro-3,3,3-trifluoropropene substantially completely from the said reaction mixture without removing hydrogen fluoride; and

a further subsequent process which gives 1,1,1,3,3-pentafluoropropane by reacting 1,3,3,3-tetrafluoropropene which is obtained by reacting 1,3,3,3-tetrafluoropropene, in an azeotropic mixture with hydrogen fluoride that does not contain HCl and 1-chloro-3,3,3-trifluoropropene, with hydrogen fluoride in a gas phase.

2. A preparation method claimed in claim 1 wherein 1,3,3,3-tetrafluoropropene is separated from crude products obtained by said first process, and 1-chloro-3,3,3-trifluoropropene and 1,1,1,3,3-pentafluoropropane unseparated from each other are transferred to said first process to be recycled.

3. A preparation method claimed in claim 1 or 2 wherein unreacted 1,3,3,3-tetrafluoropropene is separated together with hydrogen fluoride in said second process followed by being transferred to said second process to be recycled.

4. A preparation method claimed in claim 1 or 2 wherein 1,3,3,3-tetrafluoropropene obtained by said first process is prepared as an azeotropic composition with hydrogen fluoride and submitted to the material in said second process.

5. A preparation method claimed in claim 1 or 2 wherein 1-chloro-3,3,3-trifluoropropene which is obtained by reacting 1,1,1,3,3-pentachloropropane with hydrogen fluoride in the gas phase is submitted to the material in said first process.

6. A preparation method claimed in claim 5 wherein said 1-chloro-3,3,3-trifluoropropene which is prepared as an azeotropic composition with hydrogen fluoride is submitted to the material in said first process.