Method for preparing dichlorofluoroethane by catalytic fluorination with vinylidene chloride

Abstract

The invention discloses a method for preparing dichlorofluoroethane by catalytic fluorination with vinylidene chloride. The method comprises the following steps: (1) preparing vinylidene chloride, namely preparing a carbon nitride catalyst, additionally chlorinating vinyl chloride and hydrogen chloride to generate 1,1-dichloroethane, and re-chlorinating the 1,1-dichloroethane to generate 1,1,1-trichloroethane; adding the carbon-nitride catalyst into the 1,1,1-trichloroethane, reacting at 550 DEG C to obtain vinylidene chloride, cooling, sealing and storing; (2) preparing anhydrous hydrogen fluoride; and (3) synthesizing dichlorofluoroethane, namely adding vinylidene chloride and anhydrous hydrogen fluoride into an ultrasonic oscillator for mixing, performing ultrasonic oscillation for 30 minutes to obtain a reacting liquid, putting the reacting liquid into a reaction kettle, and reacting under bluelight catalysis to generate the dichlorofluoroethane. The method can be used for effectively inhibiting production of byproduct dichlorofluoroethane, and has high vinylidene chloride conversion rate and high synthesizing speed, and the production efficiency can be improved.

Description

technical field [0001] The invention relates to a method for preparing organic matter, in particular to a method for preparing monofluorodichloroethane by catalytic fluorination of vinylidene chloride. Background technique [0002] Fluorodichloroethane, a high-purity liquid widely used in cleaning and solvent applications, has been designated as an ideal replacement for fully halogenated chlorofluorocarbons due to its low impact on the ozone layer, The market demand is huge. [0003] Fluorodichloroethane is synthesized by addition reaction of vinylidene chloride and anhydrous hydrogen fluoride as raw materials. Vinylidene chloride is also known as VDC, and its chemical structure is CH 2 =CCl 2 , is a colorless liquid with a strong pungent odor and is very volatile; due to the volatility of vinylidene chloride, it is difficult to preserve it in good condition. After a period of time, the weight of vinylidene chloride will be lost, resulting in waste. [0004] In the actual...

AI Technical Summary

Problems solved by technology

[0005] 1. The conversion rate of vinylidene chloride is relatively low, and the content of the by-product difluorochloroethane produced is relatively high, resulting in low purity of monofluorodichloroethane;

[0006] 2. Due to the low purity, purification operation is required after the reaction, thus increasing production energy consumption and cost

[0007] 3. The reaction rate is slow and the production efficiency is low;

[0008] 4. There are many chemical substances involved, and the amount of waste materials is large