Technique and system for preparing dichloropropanol by autocatalysis reaction of glycerine and hydrogen chloride

Abstract

The invention discloses a technique for preparing dichloropropanol by the autocatalytic reaction of glycerol and hydrogen chloride. Glycerol and hydrogen chloride carry out autocatalytic reaction at the temperature of 105 to 160 DEG C and the pressure of 0.05 to 0.5Mpa, and the water generated in the reaction is distilled and removed. The invention also discloses a system for preparing dichloropropanol by the autocatalytic reaction of glycerol and hydrogen chloride gas. By adopting the technique of autocatalytic reaction of glycerol and hydrogen chloride, the invention avoids the using of catalyst, lowers production cost obviously, eliminates the formation of by-products with high boiling point, improves reaction selectivity and has the advantages of simple technique and low production cost. The system can transform glycerol fully and greatly improves the selectivity of dichloropropanol; the purity of the dichloropropanol obtained finally is more than 99.5 percent.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a process for preparing dichloropropanol through autocatalytic reaction of glycerin and hydrogen chloride and a system thereof. Background technique [0002] Epichlorohydrin is an important raw material for the production of epoxy resin, chlorohydrin rubber, stabilizer, surfactant, flame retardant, oilfield chemicals and other products, and dichloropropanol is a key intermediate for its synthesis. The method for industrially producing dichloropropanol is mainly based on the method described in U.S. Patent No. 4,634,784. Two series steps of high-temperature chlorination of propylene and hypochlorination of propylene chloride are used to obtain dichloropropanol. The yield of this method is low, and the production process The amount of sewage is large. In recent years, due to the rise of the biodiesel industry, the amount of by-product glycerin has increased sharply. Th...

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Problems solved by technology

Patent CN101029000A then adopts aliphatic nitrile or aromatic nitrile as catalyzer, this method needs to be passed into glycerin before hydrogen chloride gas, at reaction temperature organic nitrile is activated in 30% hydrochloric acid solution, loaded down with trivial details, simultaneously organic nitrile catalyst is in this reaction Under the same conditions, corresponding acids or carboxylic acid esters will also be generated, which will increase the consumption of catalysts.

[0005] The above-mentioned method of using glycerol as raw material and adopting organic acid or organic nitrile to catalyze the synthesis of dichloropropanol all has the problem that the catalyst reacts with the raw material or the product to generate various by-products, which leads to a large consumption of the catalyst, high energy consumption for separation, and increased production capacity. cost and environmental pollution

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