Process for producing benzyl chlorides chemical compound

Abstract

The invention discloses a method for producing benzyl chloride compounds. The method is to continuously feed the total amount of toluene compound and chlorine gas into the reactor coupled with the rectification tower according to a certain molar ratio, and the reacted material enters the rectification area, and then enters the next-stage reactor for chlorination Reaction; under continuous and stable operating conditions, control the operating pressure of the rectification tower at 0.002-0.1 MPa. The chlorination reaction is initiated by sunlight or blue light, and the temperature in the reactor is 80-120°C. The advantage of the process of the present invention is that the process flow is short, the operating conditions of the reactor and the rectifying tower are independent, and the control is flexible; the conversion rate of toluene or chlorotoluene is high, the selectivity of benzyl chloride or chlorobenzyl chloride is high, and the material is continuously discharged from the tower kettle The benzyl chloride or chlorinated benzyl chloride has a mole fraction of more than 99%, low production cost and high economic benefit.

Description

technical field [0001] The invention relates to a method for producing benzyl chloride compounds, specifically, toluene or chlorotoluene is directly chlorinated with chlorine to generate benzyl chloride or chlorobenzyl by using a method coupled with a reactor and a rectification tower Chlorine method. Background technique [0002] Benzyl chloride, also known as benzyl chloride or phenylmethane, is an important organochlorine intermediate widely used in pesticides, medicines, spices, plastic additives, surfactants, etc., and can be used to produce benzyl alcohol, benzaldehyde, Phenylacetonitrile, phenylacetic acid, benzyl butylamine, butyl benzyl phthalate, benzyl quaternary ammonium salt, etc. The cyclic chlorine derivatives of benzyl chloride include p-chlorobenzyl chloride and o-chlorobenzyl chloride and the like. P-chlorobenzyl chloride, also known as p-chlorobenzyl chloride, is an intermediate of medicine, pesticide insecticide, herbicide and dye, and can be used to pr...

AI Technical Summary

Problems solved by technology

[0007] The selectivity of benzyl chloride compounds can be improved by adopting chlorination rectification technology, but the integration of chlorination reaction and rectification in a tower equipment has the following defects: (1) the size of the reaction space is limited by the rectification tower structure

For the gas-liquid heterogeneous reaction of toluene chlorination, it is necessary to provide enough reaction space to keep the liquid holdup as large as possible. The liquid holdup of the packed tower itself is relatively small, which is difficult to meet the needs of large-scale production.

If a plate tower is used, the reaction section needs to have a larger tower diameter and a higher overflow weir than the rectification section, which will inevitably cause inconsistencies in the equipment size and fluid mechanical properties of the reaction zone and the rectification zone, which will increase the design and complexity of the rectification column. Difficulty in stable operation

(2) Benzyl chloride compounds are often produced by photocatalytic chlorination, and it is difficult to provide light to the reaction area in the reactive distillation tower

The suitable operating conditions for the side chain chlorination of methylbenzene compounds are normal pressure and temperature at 95-105°C, while the boiling points of the chlorinated target products benzyl chloride, o-chlorobenzyl chloride, and p-chlorobenzyl chloride are 179.4°C, respectively. , 217°C and 222°C, if the normal pressure operation is adopted, the reactive distillation requires a high temperature heat source and high energy consumption, and the long-term cooking of the product at high temperature will also cause problems such as coking

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