System and method for continuously synthesizing high-purity 3-chloro-1,2-propylene glycol

Abstract

The invention discloses a system and a method for continuously synthesizing high-purity 3-chloro-1,2-propylene glycol. The system includes, in a successively connection manner through pipelines, an overhead tank, a static mixer, a tubular reactor, a hydrolysate intermediate tank, a distillation kettle, a distillation column and a condenser. An output pipeline on the condenser is respectively connected to a first receiving pot, a second receiving pot and a finish product receiving pot. The receiving pots are connected to a hydraulic jet vacuum pump and a Roots-oil ring vacuum machine set at the same time. The method includes the steps of pre-heating epoxy chloropropane and softened water, mixing the epoxy chloropropane and the softened water in the static mixer according to ratio, feeding the mixture into the tubular reactor, controlling the vacuum degree and temperature of the reaction liquid in the distillation kettle to produce different fractions, and finally producing the fraction at specified vacuum degree and temperature as a finish product.

Description

technical field [0001] The invention relates to the technical field of organic synthesis, in particular to a system and method for continuously synthesizing high-purity 3-chloro-1,2-propanediol. Background technique [0002] 3-Chloro-1,2-propanediol (also known as chlorinated glycerol in the industry) is one of the important chlorinated products of glycerol, used as an intermediate in organic synthesis for the preparation of plasticizers, surfactants, dyes, drugs and glycerol Derivatives, etc.; As a solvent, it is used in the production of cellulose acetate, etc., and is widely used in chemical, pharmaceutical, coating and other industries. [0003] Chinese patent (application number 201410174437.7) proposes a method for preparing chlorinated glycerin by hydrolyzing epichlorohydrin. When hydrolyzing, sulfuric acid is used as a catalyst, the molar ratio of epichlorohydrin and water is 1:4.25~4.5, the temperature is 95~98°C, the reaction time is 1~3 hours, cooled to 60~70°C, ...

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Problems solved by technology

However, most of the above-mentioned patents and traditional synthesis processes adopt intermittent production, and the reaction time is long. During the hydrolysis reaction, the control of temperature, pressure, heat and mass transfer, etc. is difficult to achieve stability, so that the quality stability of different batches of products cannot be guaranteed. , and the quality index varies greatly between different batches; the molar ratio of deionized water to epichlorohydrin is too large, that is, the amount of deionized water is too much when feeding, one is to aggravate the process of side reactions, and the other is to increase the subsequent distillation. The operation time is shortened, and the energy consumption is large; the yield is low, and the current product yield is up to 92%; the production cycle is long, and the production cycle of a batch of products is about 24 hours; there are many distillation residues; the products produced by the existing process can be stored at room temperature for three Turns pale yellow or grass green after a month

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