Method for purifying trans-1,3,3,3-tetrafluoropropene

• US 9,174,897 B2
• Filed: 06/27/2013
• Issued: 11/03/2015
• Est. Priority Date: 06/28/2012
• Status: Expired due to Fees

• Current Assignee: Central Glass Company Limited
• Original Assignee: Central Glass Company Limited
• Inventors: Imura, Hideaki, Takada, Naoto, Okamoto, Masamune
• Primary Examiner(s): Parsa, Jafar
• Assistant Examiner(s): BAHTA, MEDHANIT W
• Application Number:
  US13/929,261
• Publication Number:
  US 20140051896A1
• Time in Patent Office: 859 Days
• Field of Search: 570/179, 570/177, 570/262
• US Class Current: 1/1
• CPC Class Codes: C07B 2200/09 Geometrical isomers
• CPC Class Codes: C07C 17/38 Separation; Purification; Stabilisation; Use of additives
• CPC Class Codes: C07C 17/389 by adsorption on solids
• CPC Class Codes: C07C 19/08 containing fluorine
• CPC Class Codes: C07C 19/10 and chlorine
• CPC Class Codes: C07C 21/18 containing fluorine
• CPC Class Codes: C07C 21/22 containing carbon-to-carbon triple bonds

Abstract

Disclosed is a method for purifying a trans-1,3,3,3-tetrafluoropropene, in which a composition containing trans-1,3,3,3-tetrafluoropropene and at least one impurity selected from the group consisting of C₂H₃ClF₂, CF₃CH₂CHClF, CF₃CH₂CHF₂, CHF₂CH═CF₂, CF₃CH═CHCl, CF₃CH═CH₂, CF₃C≡CH, and cis-1,3,3,3-tetrafluoropropene is brought into contact with a solid adsorbent to reduce an impurity content thereof. By this method, it is possible to remove the impurity in trans-1,3,3,3-tetrafluoropropene by a simple operation.

Claims

1. A method for purifying a trans-1,3,3,3-tetrafluoropropene, comprising the steps of:

(a) dechlorinating a molecular sieve 13X to prepare a dechlorinated molecular sieve 13X; and

(b) bringing a composition containing trans-1,3,3,3-tetrafluoropropene and at least one impurity selected from the group consisting of C₂H₃ClF₂, CF₃CH₂CHClF, CF₃CH₂CHF₂, CHF₂CH═

CF₂, CF₃CH═

CHCl, CF₃CH═

CH₂, CF₃C≡

CH, and cis-1,3,3,3-tetrafluoropropene into contact with the dechlorinated molecular sieve 13X as a solid adsorbent to reduce an impurity content thereof.

2. The purification method according to claim 1, wherein at least one impurity is selected from the group consisting of cis-1,3,3,3-tetrafluoropropene and CF₃CH₂CHF₂.

4. The purification method according to claim 1, wherein the dechlorination is conducted by immersing the molecular sieve 13X in an ion-exchanged water containing no chlorine ions or pure water.

5. The purification method according to claim 1, wherein the dechlorination is conducted by immersing the molecular sieve 13X in an alkali metal fluoride aqueous solution and then washing the molecular sieve 13X with an ion-exchanged water.

6. The purification method according to claim 5, wherein the alkali metal fluoride aqueous solution has a concentration of from 0.1 mass % to 5 mass % of an alkali metal fluoride.

7. The purification method according to claim 6, wherein the alkali metal fluoride is selected from the group consisting of KF, NaF, and CsF.

8. The purification method according to claim 7, wherein the alkali metal fluoride is NaF.

9. The purification method according to claim 1, further comprising the step of drying the dechlorinated molecular sieve 13X by heating.

3. A solid-liquid, heterogeneous mixture, comprising:

(a) a composition containing trans-1,3,3,3-tetrafluoropropene and at least one organic matter selected from the group consisting of C₂H₃ClF₂, CF₃CH₂CHClF, CF₃CH₂CHF₂, CHF₂CH═

CF₂, CF₃CH═

CHCl, CF₃CH═

CH₂, CF₃C≡

CH, and cis-1,3,3,3-tetrafluoropropene, and

(b) a dechlorinated molecular sieve 13X as a solid adsorbent.