WO2019084977A1 - Production method for vinylidene fluoride monomer - Google Patents

Abstract

Disclosed is a production method for a vinylidene fluoride monomer, comprising the following steps: 1) using difluoromono-chloroethane as a raw material, introducing same into a first-stage pyrolyzer, and enabling a pyrolytic reaction at a temperature of 450°C for 1 h; 2) introducing pyrolytic gas into a second-stage pyrolyzer, and enabling pyrolysis at a temperature of 1100°C; 3) sequentially introducing the gas into a reaction buffer device, a compressor, and a condenser, recovering difluoromono-chloroethane that is not involved in the reaction by using a recovery device, and introducing the recovered difluoromono-chloroethane into the first-stage pyrolyzer again; 4) introducing vinylidene fluoride passing through the condenser into a light component removal column to remove light components; and 5) introducing vinylidene fluoride into a fractionating column to obtain a vinylidene fluoride monomer. The production method for a vinylidene fluoride monomer of the present invention can effectively improve the production efficiency and reduce raw material waste.

Description

Method for producing vinylidene fluoride monomer Technical field

The present invention relates to a process for producing a vinylidene fluoride monomer.

Background technique

At present, the method for producing VDF monomer mainly uses difluorochloroethane as a raw material, and is subjected to air tube cracking or water vapor dilution cracking, and after a series of pretreatment steps, the VDF monomer is finally obtained by rectification. In the actual production process, the cracking is insufficient, resulting in excessive waste of raw materials.

Summary of the invention

The object of the present invention is to solve the above problems.

In order to achieve the above object, the technical solution of the present invention is to design a method for producing a vinylidene fluoride monomer, comprising the following steps:

1) using difluoro-chloroethane as a raw material, passing into a primary cracking furnace, the cracking temperature is 450 ° C, and reacting for 1 h;

2) The above cracked gas is passed into the secondary cracking furnace, and the cracking temperature is 1100 ° C;

3) passing the above gas through a sequential reaction buffer device, a compressor, a condenser, and recovering the difluorochloroethane which is not involved in the reaction by using a recovery device, and the recovered difluorochloroethane is re-entered into the primary cracking furnace;

4) passing the vinylidene fluoride passing through the condenser into the de-lighting tower to remove the light component;

5) The vinylidene fluoride is passed through a rectification column to a vinylidene fluoride monomer.

The invention has the advantages and beneficial effects of providing a method for producing a vinylidene fluoride monomer, which is divided into a primary cracking process and a secondary cracking process, and a lower primary cracking temperature mainly serves as a preheating effect on the raw material gas. And partial cracking, the secondary cracking temperature is higher, and the raw material gas is further cracked. The production method of the vinylidene fluoride monomer of the invention can effectively improve the production efficiency and reduce the waste of raw materials.

Detailed ways

The specific embodiments of the present invention are further described below in conjunction with the drawings and embodiments. The following examples are only intended to more clearly illustrate the technical solutions of the present invention, and are not intended to limit the scope of the present invention.

Example:

A method for producing a vinylidene fluoride monomer, comprising the steps of:

1) using difluoro-chloroethane as a raw material, passing into a primary cracking furnace, the cracking temperature is 450 ° C, and reacting for 1 h;

2) The above cracked gas is passed into the secondary cracking furnace, and the cracking temperature is 1100 ° C;

3) passing the above gas through a sequential reaction buffer device, a compressor, a condenser, and recovering the non-reactive reaction by using a recovery device. Difluorochloroethane, recovered difluorochloroethane re-entered into the primary cracking furnace;

4) passing the vinylidene fluoride passing through the condenser into the de-lighting tower to remove the light component;

5) The vinylidene fluoride is passed through a rectification column to a vinylidene fluoride monomer.

The above description is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make several improvements and retouchings without departing from the technical principles of the present invention. It should also be considered as the scope of protection of the present invention.

Claims (1)

A method for producing a vinylidene fluoride monomer, comprising the steps of: 1) using difluoro-chloroethane as a raw material, passing into a primary cracking furnace, the cracking temperature is 450 ° C, and reacting for 1 h; 2) The above cracked gas is passed into the secondary cracking furnace, and the cracking temperature is 1100 ° C; 3) passing the above gas through a sequential reaction buffer device, a compressor, a condenser, and recovering the difluorochloroethane which is not involved in the reaction by using a recovery device, and the recovered difluorochloroethane is re-entered into the primary cracking furnace; 4) passing the vinylidene fluoride passing through the condenser into the de-lighting tower to remove the light component; 5) The vinylidene fluoride is passed through a rectification column to a vinylidene fluoride monomer.