Method for purifying (hydro)halocarbon by reduced pressure distillation from azeotropic or azeotropic-like composition

Patent metadata

Field	Value
Publication number	US-12448343-B2
Application number	US-202217946707-A
Country	US
Kind code	B2
Filing date	Sep 16, 2022
Priority date	Mar 19, 2020
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

According to an embodiment, a method for producing a (hydro)halocarbon includes a step of purifying the (hydro)halocarbon by reduced-pressure distillation of an azeotropic or azeotropic-like composition containing the (hydro)halocarbon and a compound different from the (hydro)halocarbon. According to another embodiment, a method for producing a (hydro)halocarbon includes a step purifying the (hydro)halocarbon by reduced-pressure distillation of an azeotropic or azeotropic-like composition containing the (hydro)halocarbon and a compound different from the (hydro)halocarbon, wherein standard boiling points of both the (hydro)halocarbon and the compound are 80° C. or lower.

First claim

What is claimed is:

1. A method for producing a (hydro)halocarbon comprising:
a step of purifying a (hydro)halocarbon by reduced-pressure distillation of an azeotropic or azeotropic-like composition containing the (hydro)halocarbon and a compound different from the (hydro)halocarbon, wherein:
the (hydro)halocarbon is cis-1-chloro-3,3,3-trifluoropropene and the compound different from the (hydro)halocarbon is 3-chloro-1,1,1,3-tetrafluoropropane, or
the (hydro)halocarbon is cis-1,2-dichloro-3,3,3-trifluoropropene and the compound different from the (hydro)halocarbon includes at least one of 1,1-dichloro-3,3,3-trifluoropropene and trans-1,2-dichloro-3,3,3-trifluoropropene, or
the (hydro)halocarbon is cis-1,2-dichloro-3,3-difluoropropene and the compound different from the (hydro)halocarbon includes at least one of trans-1,2-dichloro-3,3-difluoropropene, hydrogen fluoride, and water, or
the (hydro)halocarbon is trans-1-chloro-3,3,3-trifluoropropene and the compound different from the (hydro)halocarbon includes at least one of 1,1,1,3,3-pentafluoropropane, 2-chloro-3,3,3-trifluoropropene, cis-1-chloro-1,3,3,3-tetrafluoropropene, 2-chloro-1,3,3,3-tetrafluoropropene, hydrogen fluoride, and water, or
the (hydro)halocarbon is cis-1-chloro-2,3,3-trifluoro-1-propene and the compound different from the (hydro)halocarbon includes at least one of trans-1-chloro-2,3,3-trifluoro-1-propene, hydrogen fluoride, and water, and
wherein the reduced-pressure distillation is performed using a distillation column with a column top pressure of 50 kPa or less.

2. A method for producing cis-1-chloro-3,3,3-trifluoropropene comprising:
a step of recovering a fraction containing cis-1-chloro-3,3,3-trifluoropropene as a major component by reduced-pressure distillation of an azeotropic or azeotropic-like composition containing cis-1-chloro-3,3,3-trifluoropropene and saturated hydrohalocarbon containing at least 3-chloro-1,1,1,3-tetrafluoropropane; and
a step of obtaining cis-1-chloro-3,3,3-trifluoropropene with a content of 3% by mass or less of 3-chloro-1,1,1,3-tetrafluoropropane by further reduced-pressure distillation of the fraction,
wherein the reduced-pressure distillation is performed using a distillation column with a column top pressure of 50 kPa or less.

3. The method for producing cis-1-chloro-3,3,3-trifluoropropene according to claim 2 , further comprising a step of purifying cis-1-chloro-3,3,3-trifluoropropene by contacting the fraction with a base after the step of recovering the fraction and before the step of obtaining cis-1-chloro-3,3,3-trifluoropropene.

4. The method for producing cis-1-chloro-3,3,3-trifluoropropene according to claim 3 , wherein the step of purifying cis-1-chloro-3,3,3-trifluoropropene is a step of dehydrohalogenation of 3-chloro-1,1,1,3-tetrafluoropropane contained in the fraction.

5. The method for producing cis-1-chloro-3,3,3-trifluoropropene according to claim 3 , wherein the base is at least one selected from the group consisting of hydroxides, carbonates, phosphates, alkoxides, oxides, and hydrides of alkali metals or alkaline earth metals.

6. A method for producing cis-1,2-dichloro-3,3,3-trifluoropropene comprising:
a step of recovering a fraction containing cis-1,2-dichloro-3,3,3-trifluoropropene as a major component by reduced-pressure distillation of an azeotropic or azeotropic-like composition containing cis-1,2-dichloro-3,3,3-trifluoropropene and at least one of trans-1,2-dichloro-3,3,3-trifluoropropene and 1,1-dichloro-3,3,3-trifluoropropene; and
a step of obtaining cis-1,2-dichloro-3,3,3-trifluoropropene with content of 3% by mass or less of at least one of trans-1,2-dichloro-3,3,3-trifluoropropene and 1,1-dichloro-3,3,3-trifluoropropene by further reduced-pressure distillation of the fraction,
wherein the reduced-pressure distillation is performed using a distillation column with a column top pressure of 50 kPa or less.

7. The method for producing cis-1,2-dichloro-3,3,3-trifluoropropene according to claim 6 , further comprising a step of purifying cis-1,2-dichloro-3,3,3-trifluoropropene by contacting the fraction with a base after the step of recovering the fraction and before the step of obtaining cis-1,2-dichloro-3,3,3-trifluoropropene.

8. The method for producing cis-1,2-dichloro-3,3,3-trifluoropropene according to claim 7 , wherein the step of purifying cis-1,2-dichloro-3,3,3-trifluoropropene is a step of dehydrohalogenation of at least one of trans-1,2-dichloro-3,3,3-trifluoropropene and 1,1-dichloro-3,3,3-trifluoropropene contained in the fraction.

9. The method for producing cis-1,2-dichloro-3,3,3-trifluoropropene according to claim 7 , wherein the base is at least one selected from the group consisting of hydroxides, carbonates, phosphates, alkoxides, oxides, and hydrides of alkali metals or alkaline earth metals.

Assignees

• Central Glass Co Ltd

Inventors

• Yoshikawa Satoshi
• Imura Hideaki
• NISHINAKA Naoki

Classifications

• C07C41/58

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

• C07C29/82

  by azeotropic distillation · CPC title

• C07C17/386 Primary

  with auxiliary compounds · CPC title

• C07C31/38

  containing only fluorine as halogen · CPC title

• C07C43/12

  containing halogen · CPC title