Preparation method of dichloro propanol from glycerin

Abstract

The invention relates to a method for preparing dichloropropanol from glycerol. Firstly, glycerin, HCl and carboxylic acid catalyst are added into a mixer, continuously pressed into a tubular reactor for chlorination reaction, and the glycerol is rapidly transformed through the reaction in the tubular reactor. The reactant then enters the HCl bubbling tank to continue the reaction. Here, the water generated by the reaction forms an azeotrope with dichloropropanol, HCl and some catalysts and evaporates from the upper part of the bubbling kettle. The product dichloropropanol is obtained at the top of the distillation tower, and the bottom liquid of the rectification tower is sent to the circulation reaction. The reactor combination method proposed by the present invention is designed according to the characteristics of the different stages of the reaction, so that the reaction rate is increased, the utilization rate of the equipment is improved, and the glycerol is completely converted within 12 to 16 hours, and the yield of dichloropropanol can be greater than 90%. , HCl utilization increased to over 70%.

Description

technical field

[0001] The invention belongs to the field of chemical industry, and relates to a preparation method of a propylene oxide intermediate. More specifically a process for the preparation of dichloropropanol from glycerol. Background technique

[0002] Dichloropropanol is a key intermediate in the production of epichlorohydrin, and its annual output is close to 2 million tons. The main method of producing dichloropropanol worldwide is based on the high-temperature chlorination of propylene developed by the American shell company in 1948. The preparation process includes:

[0003]

[0004]

[0005] Such a process has a mature process and sufficient sources of raw material propylene, which can meet the huge market demand, but this process route also has serious disadvantages: ①High temperature chlorination, high energy consumption, and many side reactions; ②The reaction process is prone to coking, The equipment needs to be shut down frequently to clean the c...

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