Method for producing dichloropropanol

Abstract

The invention provides a method for producing dichloropropanol, a chlorination agent and glycerol are adopted for reaction, and water generated by the reaction is continuously removed under the condition of taking a phosphorous acid derivative or a phosphoric acid derivative or a phosphorus chloride derivative as a catalyst, thereby obtaining the dichloropropanol. The method overcomes the shortcomings of product pollution, great separation difficulty and impact on yield which are caused by volatilization of carboxylic acid catalysts and the shortcomings of high price and lower catalytic efficiency of non-volatile organic acid catalysts in the prior art, reduces the using amount of the catalyst and simultaneously improves the product yield.

Description

technical field [0001] The invention belongs to the field of chemical industry, and relates to a preparation method of an epichlorohydrin intermediate, more specifically a method for preparing dichloropropanol from glycerin. Background technique [0002] Dichloropropanol is an important intermediate in the production of epichlorohydrin, which is an important organic chemical raw material and fine chemical product with a wide range of uses. The epoxy resin prepared from it has the characteristics of strong adhesion, resistance to chemical medium corrosion, low shrinkage, good chemical stability, high impact strength and excellent dielectric properties. It is used in coatings, adhesives, reinforcing materials, Industries such as casting materials and electronic laminates have a wide range of applications. Epichlorohydrin can also be used to synthesize nitroglycerin explosives, glass fiber reinforced plastics, electrical insulation products, surfactants, medicines, pesticides,...

AI Technical Summary

Problems solved by technology

[0009] The catalyzers of these patents all adopt acetic acid or volatile larger carboxylic acid as catalyzer, and in the reaction process, part of the catalyst forms an azeotrope with the water, dichloropropanol and HCl generated by the reaction, resulting in a large amount of catalyst and increasing the separation of products. Difficulty, and these catalysts themselves are also solvents, and part of the dichloropropanol product is inevitably brought into the acid water during the separation process, which affects the product yield and reduces the quality of the recovered waste acid

[0010] In addition, Solvay Company disclosed a process similar to the aforementioned Czech Chemical Metallurgical United Company in its patent WO2005054167 (or Fr2862644). In this patent, carboxylic acids, carboxylic anhydrides, carboxylic acid chlorides, and Carboxylate or carboxylate, and adipic acid is preferred as the catalyst, so the catalyst loss is very small in the material circulation reaction, but these catalysts are relatively expensive and have relatively low catalytic efficiency