Hydrofluorocarbon recovery method

Patent metadata

Field	Value
Publication number	US-9994649-B2
Application number	US-201515319134-A
Country	US
Kind code	B2
Filing date	Jun 2, 2015
Priority date	Jun 17, 2014
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

Abstract

A method for recovering a hydrofluorocarbon, including: producing a wet fluoropolymer by suspension polymerization, solution polymerization, or bulk polymerization in the presence of a hydrofluorocarbon; vaporizing and discharging vaporizable substances including the hydrofluorocarbon by heating the wet fluoropolymer in a container; and transferring the discharged vaporizable substances to a cooling means to cool the substances.

First claim

The invention claimed is:

1. A method for recovering a hydrofluorocarbon, comprising:
producing a wet fluoropolymer by suspension polymerization, solution polymerization, or bulk polymerization in the presence of a hydrofluorocarbon;
vaporizing and discharging vaporizable substances including the hydrofluorocarbon by heating the wet fluoropolymer in a container; and
transferring the discharged vaporizable substances to a cooling means to cool the substances, and
wherein x/V is at most 0.140,
wherein V represents an inner volume (L) of the container, and x represents a discharge rate (kg/hour) of the vaporizable substances discharged from the container.

2. The method for recovering a hydrofluorocarbon according to claim 1 ,
wherein the hydrofluorocarbon has a boiling point of −10° C. to 100° C.

3. The method for recovering a hydrofluorocarbon according to claim 1 ,
wherein the hydrofluorocarbon has a boiling point of 0° C. to 85° C.

4. The method for recovering a hydrofluorocarbon according to claim 1 ,
wherein in the vaporizing step, the temperature in the container is 0° C. to 100° C.

5. The method for recovering a hydrofluorocarbon according to claim 1 ,
wherein the fluoropolymer has a polymerized unit derived from at least one fluoromonomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, chlorotrifluoroethylene, (perfluoromethyl)vinyl ether, (perfluoroethyl)vinyl ether, (perfluoropropyl)vinyl ether, trifluoroethylene, vinyl fluoride, perfluoro(alkyl vinyl ethers) represented by the formula (2-1):
CF 2 ═CFO(CF 2 CF(Y)O) m (CF 2 ) n F  (2-1)

wherein Y represents a fluorine atom or a trifluoromethyl group, m is an integer of 0 to 2, and n is an integer of 1 to 4, monomers represented by the formula (2-2):
CH 2 ═CF(CF 2 ) n Z  (2-2)

wherein Z represents a fluorine atom or a hydrogen atom, and n is an integer of 1 to 8, and monomers represented by the formula (2-3):
CH 2 ═CH(CF 2 ) n Z  (2-3)

wherein Z represents a fluorine atom or a hydrogen atom, and n is an integer of 1 to 8.

6. The method for recovering a hydrofluorocarbon according to claim 1 ,
wherein the fluoropolymer has a polymerized unit derived from tetrafluoroethylene and a polymerized unit derived from ethylene.

7. The method for recovering a hydrofluorocarbon according to claim 1 , further comprising transferring the vaporizable substances liquefied by cooling in the cooling step to a distillation means to distill the substances.

8. The method for recovering a hydrofluorocarbon according to claim 1 ,
wherein a fluorine-containing compound having a lower boiling point than the hydrofluorocarbon is added to the wet fluoropolymer.

9. The method for recovering a hydrofluorocarbon according to claim 1 , further comprising transferring the vaporizable substances vaporized in the vaporizing step to a compression means to compress the substances.

10. The method for recovering a hydrofluorocarbon according to claim 9 ,
wherein the compression means is a compressor.

11. The method for recovering a hydrofluorocarbon according to claim 1 ,
wherein the cooling means is a condenser.

12. A method for using a hydrofluorocarbon comprising:
reusing a hydrofluorocarbon recovered by the method for recovering a hydrofluorocarbon according to claim 1 .

Assignees

• Daikin Ind Ltd

Inventors

• ZENKE Yumi
• Isaka Tadaharu
• Fukagawa Ryouichi
• Shimono Takeshi

Classifications

• C08F6/10 Primary

  Removal of volatile materials, e.g. solvents {(C08F6/001, C08F6/003, C08F6/005, C08F6/006, C08F6/008, C08F6/02, C08F6/04 take precedence)} · CPC title

• C08F6/003 Primary

  from polymer solutions, suspensions, dispersions or emulsions without recovery of the polymer therefrom · CPC title

• C08J11/02

  of solvents, plasticisers or unreacted monomers · CPC title

• C08F14/18

  Monomers containing fluorine · CPC title

• C08F2/06

  Organic solvent · CPC title