Production process for reducing impurity dichlorobenzene in chlorobenzene

A production process, a technology for chlorinating benzene, applied in the directions of organic chemistry, organic chemistry methods, chemical instruments and methods, etc., can solve the problems of reducing the reaction efficiency, the iron ring is easily corroded, and the chlorine gas is consumed, so as to improve the reaction efficiency and catalysis Efficient effect and stable bonding method

Active Publication Date: 2022-06-14
ANHUI DONGZHI GUANGXIN AGROCHEMICAL CO LTD
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  • Abstract
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  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

It can be seen that in the production system of chlorinated benzene, the existence of trace water is needed to ensure the occurrence of the reaction, but if the water content is too high, it is easy to cause the generated hydrogen chloride gas to dissolve in water to form hydrochloric acid, which will react with the iron ring to release a large amount of hydrogen gas. Prone to explosion, in addition, generating a large amount of ferrous chloride will consume chlorine gas, produce a large amount of ferric chloride, cause the generation of dichlorinated benzene by-products, and reduce the yield of chlorinated benzene
Therefore, when using the iron ring as the catalyst catalyst, there are the following disadvantages: the reaction is difficult to control; the iron ring is susceptible to corrosion, which reduces the contact area and reduces the reaction efficiency; the content of dichlorinated benzene by-products is high

Method used

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  • Production process for reducing impurity dichlorobenzene in chlorobenzene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Preparation of modified mesoporous silica:

[0031] A1. Add 0.6g of sodium N-laurate sarcosinate to 70mL of deionized water, then add 14mL of 0.1M hydrochloric acid solution, stir for 1 hour, then add 2mL of ethyl orthosilicate, stir at 600r / min for 30min, and age at room temperature 2h, then poured into the reaction kettle, placed in an oven at 80°C for 24h, then centrifuged, washed the precipitate with deionized water, and vacuum-dried to obtain dry powder; then the dry powder was dispersed in ethanol and ethanolamine with a molar ratio of 3.3 / 1 In the mixed solution of , refluxed for 12h, centrifuged, washed several times with 70mL of ethanol, and vacuum-dried for 24h to obtain mesoporous silica. The dosage ratio of the dry powder to the mixed solution of ethanol and ethanolamine was 1:15;

[0032] A2. Add 0.01mol of potassium to 8mL of dry tert-butanol, stir until the potassium is completely dissolved, then slowly add 0.01mol of acetylacetone dropwise at room temper...

Embodiment 2

[0035] Preparation of modified mesoporous silica:

[0036]A1. Add 0.65g of sodium N-laurate sarcosinate to 90mL of deionized water, then add 17mL of 0.1M hydrochloric acid solution, stir for 1h, then add 3mL of ethyl orthosilicate, stir at 600r / min for 60min, and store at room temperature 2 hours, then poured into the reaction kettle, placed in an oven at 80°C for 24 hours, centrifuged again, washed the precipitate with deionized water, and dried in vacuum to obtain dry powder; then the dry powder was dispersed in a molar ratio of 3.3 / 1 ethanol and In the mixed solution of ethanolamine, reflux for 12 hours, centrifuge, wash with 70 mL of ethanol for several times, and vacuum dry for 24 hours to obtain mesoporous silica. The dosage ratio of the dry powder to the mixed solution of ethanol and ethanolamine is 1:20;

[0037] A2. Add 0.01 mol potassium to 15 mL of dry tert-butanol, stir until the potassium is completely dissolved, then slowly add 0.01 mol of acetylacetone dropwise ...

Embodiment 3

[0040] A production technique for reducing impurity dichlorobenzene in chlorinated benzene, comprising the following steps:

[0041] Step 1. Put the modified mesoporous silica prepared in Example 1 into the ferric chloride solution, stir at room temperature for 1.5 hours, stand for 12 hours, centrifuge, wash several times with deionized water, filter again, and precipitate in drying in a vacuum oven to obtain a supported catalyst, wherein the solid-to-liquid ratio of the modified mesoporous silica and the ferric chloride solution is 1g:15mL, and the mass concentration of the ferric chloride solution is 10%;

[0042] Step 2, adding the supported catalyst into the reactor, then adding benzene, feeding chlorine gas, using self-priming stirring to distribute the chlorine gas in the benzene, controlling the reaction temperature to be 78°C, and after reacting for 90 minutes, release a chlorinated liquid containing benzene. Hydrogen chloride gas is discharged from the top of the reac...

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Abstract

The invention relates to a production process for reducing impurity dichlorobenzene in chlorobenzene, and belongs to the technical field of chlorobenzene production, and the production process comprises the following steps: step 1, putting modified mesoporous silica into a ferric chloride solution, stirring at room temperature for 1.5-2 hours, standing for 12 hours, centrifuging, washing with water, filtering again, precipitating and drying to obtain a supported catalyst; and 2, adding the supported catalyst into a reactor, adding benzene, introducing chlorine, controlling the reaction temperature, reacting for 60-90 minutes, discharging a chlorination liquid, and purifying the chlorination liquid to obtain the chlorinated benzene. The mesoporous silica supported ferric chloride is used as a catalyst for chlorobenzene reaction, the supported catalyst has the advantage of high activity, and the addition amount of the ferric chloride is easily controlled by controlling the amount of the supported catalyst, so that the content of the ferric chloride is in a reasonable range, and the generation of a large amount of dichlorobenzene is avoided.

Description

technical field [0001] The invention belongs to the technical field of chlorinated benzene production, and in particular relates to a production process for reducing the impurity dichlorobenzene in the chlorinated benzene. Background technique [0002] Chlorinated benzene is an important basic organic synthesis raw material, which is widely used in the fields of dyes, medicine, rubber and pesticides. The production process is that benzene and chlorine undergo electrophilic substitution reaction under the catalysis of ferric chloride, and heat is released during the reaction. The chlorination reaction of benzene requires less catalyst ferric chloride, and the dissolved amount of ferric chloride in benzene is 0.006%-0.01% (mass fraction, the same below) can meet the requirements. When the dissolved amount is lower than 0.006%, the chlorination reaction is difficult to carry out; when the dissolved amount reaches 0.01%, it is sufficient to meet the needs of the chlorination re...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C17/12C07C17/383C07C25/06B01J31/22C07F7/18
CPCC07C17/12C07C17/383B01J31/2213C07F7/1804C07F7/1892B01J2531/842B01J2531/0213C07B2200/11C07C25/06Y02P20/52
Inventor 查日飞汪金根张武生朱金麟刘会志方竹青陶秀芳
Owner ANHUI DONGZHI GUANGXIN AGROCHEMICAL CO LTD
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