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

Patent metadata

Field	Value
Publication number	US-9975824-B2
Application number	US-201515514901-A
Country	US
Kind code	B2
Filing date	Jul 7, 2015
Priority date	Sep 30, 2014
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

This invention provides a method capable of efficiently producing 2,3,3,3-tetrafluoropropene (HFO-1234yf) with a recycling step using substantially a single reaction step. A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf), comprising a reaction step of reacting at least one chlorine-containing starting compound selected from the group consisting of chlorine-containing alkanes represented by formula (1): CX 2 YCHClCH 2 Z (wherein X, Y and Z independently represent H, F or Cl) and chlorine-containing alkenes represented by formula (2): CX 2 YCCl═CZ 2 (wherein X, Y and Z independently represent H, F or Cl) with a fluorinating agent, wherein the molar ratio of the chlorine-containing starting compound represented by formula (1) or (2) newly supplied to the reactor inlet is less than 1.2 relative to 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) in components obtained from the reactor outlet.

First claim

The invention claimed is:

1. A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf), comprising a reaction step of reacting at least one chlorine-containing starting compound selected from the group consisting of:
chlorine-containing alkanes of the following formula (1):
CX 2 YCHClCH 2 Z,

wherein X, Y and Z independently represent H, F or Cl; and
chlorine-containing alkenes of the following formula (2):
CX 2 YCCl═CZ 2 ,

wherein X, Y and Z independently represent H, F or Cl,
with a fluorinating agent in a reactor at a pressure of 0 to 0.3 MPaG,
wherein a concentration of HCl contained in components obtained from a reactor outlet in the reaction step is 10 mol % or less relative to a total amount of the components obtained from the reactor outlet.

2. The method according to claim 1 , wherein a molar ratio of the fluorinating agent supplied to the reactor is more than 50 relative to a molar amount of the chlorine-containing starting compound newly supplied to a reactor inlet.

3. The method according to claim 1 , wherein a molar ratio of the chlorine-containing starting compound newly supplied to a reactor inlet is 0.3 or less relative to a molar amount of HCFO-1233xf in the components obtained from the reactor outlet.

4. The method according to claim 1 , further comprising circulating at least a part of a product of the reaction step, and unreacted chlorine-containing starting compound and fluorinating agent in the reactor outlet to the reaction step.

5. The method according to claim 1 , further comprising separating HFO-1234yf and/or HCl from a product of the reaction step obtained in the reactor outlet, and circulating at least a part of a remaining product, and unreacted chlorine-containing starting compound and fluorinating agent to the reaction step.

6. The method according to claim 1 , wherein at least one chlorine-containing starting compound of the compounds of formula (1) is 1,1,1,2,3-pentachloropropane (HCC-240 db).

7. The method according to claim 1 , wherein at least one chlorine-containing starting compound of the compounds of formula (2) is 1,1,2,3-tetrachloropropene (HCO-1230xa).

8. The method according to claim 1 , wherein the fluorinating agent is anhydrous hydrogen fluoride.

9. The method according to claim 1 , wherein a catalyst used in the reaction step is a chromium oxide or a fluorinated chromium oxide.

10. The method according to claim 1 , wherein a concentration of HCl contained in components that are circulated to the reaction step is 5 mol % or less relative to a chlorine-containing compound to be circulated.

11. The method according to claim 1 , wherein O 2 and/or Cl 2 is introduced in the reaction step.

Assignees

• Daikin Ind Ltd

Inventors

• Chaki Takehiro
• Karube Daisuke

Classifications

• C07B61/00

  Other general methods · CPC title

• C07C17/25

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

• C07C17/206 Primary

  the other compound being HX · CPC title

• Y02P20/582

  Recycling of unreacted starting or intermediate materials · CPC title

• C07C21/18

  containing fluorine · CPC title