Method for co-producing various alkenyl halides and hydrofluoroalkanes

• US 10,590,050 B2
• Filed: 06/25/2018
• Issued: 03/17/2020
• Est. Priority Date: 09/07/2017
• Status: Active Grant

• Current Assignee: Zhejiang Quhua Fluorine Chemical Company Limited (Sinochem Group Co., Ltd.)
• Original Assignee: Zhejiang Quhua Fluorine Chemical Company Limited (Sinochem Group Co., Ltd.)
• Inventors: Hong, Jiangyong, Yang, Bo, Zhang, Yan, Yu, Guojun, Zhao, Yang, Ouyang, Hao, Gong, Haitao
• Primary Examiner(s): Parsa, Jafar F
• Application Number:
  US16/337,407
• Publication Number:
  US 20200031742A1
• Time in Patent Office: 631 Days
• CPC Class Codes: B01J 21/04 Alumina
• CPC Class Codes: B01J 23/26 Chromium
• CPC Class Codes: B01J 23/58 with alkali- or alkaline earth metals
• CPC Class Codes: B01J 23/60 with zinc, cadmium or mercury
• CPC Class Codes: B01J 23/62 with gallium, indium, thallium, germanium, tin or lead
• CPC Class Codes: C07C 17/206 the other compound being HX
• CPC Class Codes: C07C 17/21 with simultaneous increase of the number of halogen atoms
• CPC Class Codes: C07C 17/358 by isomerisation
• CPC Class Codes: C07C 17/383 by distillation
• CPC Class Codes: C07C 19/08 containing fluorine
• CPC Class Codes: C07C 21/18 containing fluorine

Abstract

Disclosed is a method for co-producing various alkenyl halides and hydrofluoroalkanes: cis-1-chloro-3,3,3-trifluoropropene is introduced into a first reactor to carry out an isomerization reaction in the presence of a first catalyst, and the reaction product is rectified to obtain a product trans-1-chloro-3,3,3-trifluoropropene; and 30-70 wt % of trans-1-chloro-3,3,3-trifluoropropene and hydrogen fluoride are mixed and then introduced into a second reactor to carry out a reaction in the presence of a second catalyst to obtain a second reactor reaction product; the second reactor reaction product is introduced into a phase separator for separation, and the obtained organic phase is rectified to obtain the products trans-1,3,3,3-tetrafluoropropene, cis-1,3,3,3-tetrafluoropropene and 1,1,1,3,3-pentafluoropropane. The invention has the advantages of simple process, high efficiency, high operation flexibility, less investment and low energy consumption.

Claims

1. A method for co-producing alkenyl halides and hydrofluoroalkanes, comprising following steps of:

(a) introducing cis-1-chloro-3,3,3-trifluoropropene into a first reactor where an isomerization reaction occurs in the presence of a first catalyst to obtain a first reactor reaction product, wherein a temperature of the isomerization reaction is 200-400°

C., and an air velocity of the isomerization reaction is 300-1000 h<sup>−

1</sup>;

(b) introducing the first reactor reaction product obtained in the Step (a) into a first rectification column to obtain a product of trans-1-chloro-3,3,3-trifluoropropene and a first rectification column bottom liquid;

(c) mixing 30-70 wt % of the trans-1-chloro-3,3,3-trifluoropropene obtained in the Step (b) with hydrogen fluoride, and then introducing the trans-1-chloro-3,3,3-trifluoropropene and the hydrogen fluoride in a second reactor where a reaction occurs in the presence of a catalyst to obtain a second reactor reaction product, wherein a molar ratio of the hydrogen fluoride to the trans-1-chloro-3,3,3-trifluoropropene is 8-20;

1, a temperature of the reaction is 180-400°

C., and a space velocity of the reaction is 300-1000 h<sup>−

1</sup>;

(d) introducing the second reactor reaction product obtained in the Step (c) into a phase separator for separation to obtain an inorganic phase and an organic phase;

(e) introducing the organic phase obtained in the Step (d) into a second rectification column to obtain a product of trans-1,3,3,3-tetrafluoropropene and a second rectification column bottom liquid;

(f) introducing the second rectification column bottom liquid obtained in the Step (e) into a third rectification column to obtain a product of cis-1,3,3,3-tetrafluoropropene and a third rectification column bottom liquid; and

(g) introducing the third rectification column bottom liquid obtained in the Step (f) into a fourth rectification column to obtain a product of 1,1,1,3,3-pentafluoropropane and a fourth rectification column bottom liquid.

2. The method for co-producing alkenyl halides and hydrofluoroalkanes according to claim 1, wherein the first rectification column bottom liquid in the Step (b) is recycled back to the first reactor.

3. The method for co-producing alkenyl halides and hydrofluoroalkanes according to claim 1, wherein the inorganic phase in the Step (d) is recycled back to the second reactor.

4. The method for co-producing alkenyl halides and hydrofluoroalkanes according to claim 1, wherein the fourth rectification column bottom liquid in the Step (g) is recycled back to the second reactor.

5. The method for co-producing alkenyl halides and hydrofluoroalkanes according to claim 1, wherein in the Step (a) the temperature of the isomerization reaction is 250-320°

C., and the air velocity of the isomerization reaction is 500-800 h<sup>−

1</sup>.

6. The method for co-producing alkenyl halides and hydrofluoroalkanes according to claim 1, wherein in the Step (c) the molar ratio of the hydrogen fluoride to the trans-1-chloro-3,3,3-trifluoropropene is 10-15:

1, the temperature of the reaction is 200-350°

C., and the space velocity of the reaction is 500-700 h<sup>−

1</sup>.

7. The method for co-producing alkenyl halides and hydrofluoroalkanes according to claim 1, wherein the first catalyst in the Step (a) is alumina-loaded chromium and magnesium, wherein the load of chromium is 3-8 wt %, and the load of magnesium is 1-3 wt %.

8. The method for co-producing alkenyl halides and hydrofluoroalkanes according to claim 1, wherein a composition of the second catalyst in the Step (c) comprises, by mass percentage, 73-90% of chrome oxide, 9.5-25% of zinc oxide, and 0.5-2% of gallium oxide.