Preparation method of 1,1-difluoroethylene

A technology of vinylidene fluoride and ethylene chloride, which is applied in the field of preparation of 1,1-ethylene difluoride, can solve the problems that catalytic cracking cannot be industrialized, catalyst stability and service life are poor, etc., and achieves significant social and economic benefits and high cost Low, high yield effect

Active Publication Date: 2017-06-20
SHANDONG HUAXIA SHENZHOU NEW MATERIAL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Although catalytic cracking has many advantages, it also has its disadvantages, especially the...

Method used

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  • Preparation method of 1,1-difluoroethylene
  • Preparation method of 1,1-difluoroethylene
  • Preparation method of 1,1-difluoroethylene

Examples

Experimental program
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Embodiment 1

[0029] First, the coconut shell activated carbon was treated with 20 wt% nitric acid solution at 85 °C for 2 h, and washed to neutral. The nitric acid-treated coconut shell charcoal and melamine were stirred and mixed in absolute ethanol at a mass ratio of 1:1, and then the ethanol was evaporated to dryness to obtain a mixture of activated carbon and melamine. The mixture was calcined at 800°C for 4h to obtain nitrogen-doped carbon catalyst.

[0030] Then, the obtained nitrogen-doped carbon catalyst is used to catalyze the removal of HCl from 1,1-difluoro-1-chloroethane to prepare vinylidene fluoride. The reaction is carried out in a plug-flow tube reactor. The reaction tube of the tube reactor is a Ni tube with an inner diameter of 20mm and a length of 800mm, and is placed in a heating furnace to heat up to 400°C for reaction. The reaction pressure is normal pressure. Before the reaction, pass N 2 (airspeed is 1000h -1 ), the temperature of the catalyst bed was raised fro...

Embodiment 2

[0032] The coconut shell charcoal treated with nitric acid and melamine were mixed in absolute ethanol at a mass ratio of 1:1, the ethanol was evaporated to dryness and calcined at 800°C for 4 hours to obtain a nitrogen-doped carbon catalyst.

[0033]Then, the obtained nitrogen-doped carbon catalyst is used to catalyze the removal of HCl from 1,1-difluoro-1-chloroethane to prepare vinylidene fluoride. The reaction is carried out in a plug-flow tube reactor. The reaction tube of the tube reactor is a Ni tube with an inner diameter of 20mm and a length of 800mm, and is placed in a heating furnace to heat up to 400°C for reaction. The reaction pressure is normal pressure. Before the reaction, pass N 2 (with an airspeed of 1000 h -1 ), the temperature of the catalyst bed was raised from room temperature to 200 °C at a rate of 5 °C / min and dried for 2 h. Then, the temperature was raised to 400°C at a rate of 5°C / min and the catalyst was treated for 2 hours, then the temperature ...

Embodiment 3

[0035] The coconut shell charcoal treated with nitric acid and melamine were mixed in absolute ethanol at a mass ratio of 1:1, the ethanol was evaporated to dryness and calcined at 800°C for 4 hours to obtain a nitrogen-doped carbon catalyst.

[0036] Then, the obtained nitrogen-doped carbon catalyst is used to catalyze the removal of HCl from 1,1-difluoro-1-chloroethane to prepare vinylidene fluoride. The reaction is carried out in a plug-flow tube reactor. The reaction tube of the tube reactor is a Ni tube with an inner diameter of 20mm and a length of 800mm, and is placed in a heating furnace to heat up to 400°C for reaction. The reaction pressure is normal pressure. Before the reaction, pass N 2 (with an airspeed of 1000 h -1 ), the temperature of the catalyst bed was raised from room temperature to 200 °C at a rate of 5 °C / min and dried for 2 h. Then, the temperature was raised to 400°C at a rate of 5°C / min and the catalyst was treated for 2 hours, then the temperature...

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Abstract

The invention provides a preparation method of 1,1-difluoroethylene (vinylidene fluoride (VDF)). Under the action of a catalyst, a gas phase of 1,1-difluoro-1-chloroethane (HCFC-142b) is subjected to dehydrochlorination to generate the 1,1-difluoroethylene. The catalyst is composed of a main catalyst and a co-catalyst; the main catalyst is a nitrogen-containing carbon material; the co-catalyst is chloride of transition element, alkali-earth metal and lanthanide metal. The method for preparing the 1,1-difluoroethylene, provided by the invention, has the characteristics of low reaction temperature, high product selectivity, high yield, uneasiness of blocking a pipeline, moderate conditions of a preparation process, simplicity in operation and the like.

Description

technical field [0001] The invention belongs to the technical field of preparation of chlorofluoroolefins, and specifically relates to a preparation method of 1,1-difluoroethylene with simple process, good stability, high selectivity, simple steps and easy industrialization. It consists of 1,1-difluoroethylene -1-Chloroethane is obtained by catalytic dehydrochlorination. Background technique [0002] 1,1-Difluoroethylene (also known as vinylidene fluoride or VDF) is one of the important varieties of fluorine-containing olefins, mainly used in the production of polyvinylidene fluoride resin, fluororubber and fluorine-containing copolymers such as vinylidene fluoride-hexafluoro Propylene, vinylidene fluoride-vinylidene fluoride, vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene, etc. In addition, fluorine rubber obtained by copolymerization of vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene has become an indispensable and substitute in modern indust...

Claims

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Application Information

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IPC IPC(8): C07C17/25C07C21/18B01J27/24B01J27/138B01J27/10B01J27/128
CPCB01J27/10B01J27/128B01J27/138B01J27/24C07C17/25C07C21/18
Inventor 韩文锋王志昆唐浩东李瑛刘化章
Owner SHANDONG HUAXIA SHENZHOU NEW MATERIAL
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