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A kind of method for continuously producing p-nitroaniline in series still

A p-nitroaniline, tank-type technology, applied in the field of fine chemical continuous ammonolysis unit reaction, continuous production of p-nitroaniline in series tank type, can solve the difficulty of reaction temperature and pressure control yield, short residence time of pipeline reactor , safety hazards and other issues, to achieve the effect of changing low production capacity, increasing production capacity and increasing the chance of collision

Active Publication Date: 2015-07-29
绍兴齐越化工科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] According to the deficiencies of the prior art, the present invention provides a method for continuous production of p-nitroaniline by adopting series tank type, which overcomes the control caused by unfavorable factors such as the short residence time of the pipeline reactor and the need to make the reaction temperature and pressure very high. Difficulties and insufficient yields can also change the problems of low production capacity, high energy consumption, and safety hazards caused by manual operation in single-pot batch reactions, so as to achieve the purpose of increasing production capacity, saving energy and reducing consumption.

Method used

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  • A kind of method for continuously producing p-nitroaniline in series still

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Effect test

Embodiment example 1

[0025] A method for continuous production of p-nitroaniline in series tank formula, comprising the following steps:

[0026] (1) Use liquid ammonia and water to prepare ammonia water with a mass percentage concentration of 40% in the ammonia water preparation tank, and transfer it to the ammonia water storage tank;

[0027] (2) Connect four high-pressure ammonolysis kettles in series through pipelines, each of which has a volume of 0.5m 3 ;

[0028] (3) Add ammonia water with a mass percentage concentration of 40% configured in step (1) into four high-pressure ammonolysis kettles connected in series, so that when the ammonia water in each high-pressure ammonolysis kettle reaches 50% of the kettle volume, stop feed;

[0029] (4) Slowly start the stirring, and adjust the stirring speed through the frequency regulator installed on the stirring motor of each high-pressure ammonialysis kettle, so that it gradually increases from 5 rpm to 300 rpm. At this time, the four high-press...

Embodiment example 2

[0034] (1) Use liquid ammonia and water in the ammonia water preparation tank to configure the ammonia water with a mass percentage concentration of 40%, and transfer it to the ammonia water storage tank;

[0035] (2) Three high-pressure ammonolysis kettles are connected in series through pipelines, each of which has a volume of 10m 3 ;

[0036] (3) Add ammonia water with a mass percentage concentration of 37% configured in step (1) into three high-pressure ammonolysis kettles connected in series, so that when the ammonia water in each high-pressure ammonolysis kettle reaches 50% of the kettle volume, stop feed;

[0037] (4) Slowly start the stirring, and adjust the stirring speed through the frequency regulator installed on the stirring motor of each high-pressure ammonialysis kettle, so that it can gradually increase to 400 rpm. Ammonolysis reaction is carried out for the materials in the tank. When the temperature reaches 180°C and the pressure reaches 6.1MPa, p-nitrochloro...

Embodiment 2

[0040] Obtain 2253kg of p-nitroaniline per hour in Example 2, the appearance of the product is yellowish brown, the chromatographic analysis content is 99.77%, and the yield is 98.9%.

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Abstract

The invention provides a method for continuous production of paranitroaniline by series-connected kettles. The method comprises the following steps of: adding ammonia water with mass percentage concentration of 20%-50% to two or more than two high-pressure ammonolysis kettles which are connected in series, stopping charging when ammonia water in each ammonolysis kettle accounts for 50% of the volume of the kettle, slowly starting the stirring of the ammonolysis kettle till the speed of the ammonolysis kettle rises to 200-600 r / m, then adding p-nitrchlorobenzene and ammonia water according to a molar ratio of 1: (2-10) to the first high-pressure ammonolysis kettle connected in series for carrying out continuous ammonolysis reaction when the temperature of each ammonolysis kettle is heated to 120-200 DEG C and the pressure of each ammonolysis kettle is increased to 3-9.5MPa, enabling materials reacted in the last ammonolysis kettle to enter a buffering tank for buffering, then entering a pressure relief cooling kettle for pressure relief and temperature reduction, separating the cooled materials to obtain a solid material, and drying to obtain paranitroaniline. The method has the advantages of being capable of improving the working efficiency and reducing the labor intensity and simultaneously solving the problems of unstable quality, potential safety hazards and the like caused by manual operation.

Description

technical field [0001] The invention relates to a method for continuous production of p-nitroaniline in series-connected kettles, which belongs to the category of continuous ammonolysis unit reaction in fine chemical industry. Background technique [0002] P-nitroaniline is an extremely important intermediate in the dye industry. The existing production method of p-nitroaniline is to use p-nitrochlorobenzene as raw material, and carry out high-pressure ammonolysis reaction under the condition of 33% concentrated ammonia water medium. The method of specific ammonia solution mainly contains the following two methods: [0003] The first method is to use an autoclave for intermittent ammonolysis, adding measured p-nitrochlorobenzene into the autoclave with a certain concentration (33-40%) of ammonia water, at a temperature of 170-175°C and a pressure of 4.8- Under the condition of 5.6MPa, carry out ammonolysis reaction, maintain 9-15 hours to complete the reaction, and then rec...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C211/52C07C209/10
Inventor 陈燕
Owner 绍兴齐越化工科技有限公司