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Method and device for producing phenylenediamine by taking water as solvent through liquid phase continuous hydrogenation method

A technology of phenylenediamine and hydrogenation method, which is applied in the field of phenylenediamine production by liquid-phase continuous hydrogenation as a solvent and devices, can solve the problems of affecting production safety and workers' health, being inflammable, explosive, and highly toxic, and achieving The effect of saving solvent consumption, large equipment operation flexibility, and low total content

Active Publication Date: 2012-12-19
JIANGSU KESHENG CHEM MACHINERY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Methanol is used as a solvent for recovery and recycling. Although methanol recovery is applied mechanically, there is still a certain loss in the recovery process. For example, m-phenylenediamine and p-phenylenediamine are produced from m-dinitrobenzene, p-nitroaniline, and o-nitroaniline respectively. , In the o-phenylenediamine process, the methanol consumption calculated by m-phenylenediamine, p-phenylenediamine, and o-phenylenediamine reaches 100-300 kg / ton of phenylenediamine
In addition, methanol is also flammable, explosive, and highly toxic, which affects production safety and workers' health.

Method used

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  • Method and device for producing phenylenediamine by taking water as solvent through liquid phase continuous hydrogenation method
  • Method and device for producing phenylenediamine by taking water as solvent through liquid phase continuous hydrogenation method
  • Method and device for producing phenylenediamine by taking water as solvent through liquid phase continuous hydrogenation method

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Experimental program
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Effect test

Embodiment 1

[0043] Embodiment 1: produce p-phenylenediamine according to the following steps:

[0044] (1) In the primary hydrogenation reactor 5 and the secondary hydrogenation reactor 8, first add a solution of p-phenylenediamine and water corresponding to 50% of the total volume of the reactor, and then add a solution equivalent to the above-mentioned p-phenylenediamine Amine and 1.5% nickel catalyst by weight in aqueous solution; the weight ratio of p-phenylenediamine to water is 3:7;

[0045] (2) Turn on the cooling water of the heat exchange coil and keep the reaction temperature at 90°C;

[0046] (3) When stirring at 90°C, continuously feed hydrogen into the primary hydrogenation reactor 5 and the secondary hydrogenation reactor 8; The pressure in the stage hydrogenation reactor 8 remains on 1.3MPa;

[0047] (4) When the hydrogen pressure in the kettle reaches 1.3MPa, continuously add water and p-nitroaniline into the primary hydrogenation reactor 5, and the speed of adding wat...

Embodiment 2

[0052] Embodiment 2: produce p-phenylenediamine according to the following steps:

[0053] (1) In the primary hydrogenation reactor 5 and the secondary hydrogenation reactor 8, first add a solution of p-phenylenediamine and water corresponding to 60% of the total volume of the reactor, and then add a solution equivalent to the above-mentioned phenylenediamine and a nickel-based catalyst of 1% by weight of the aqueous solution; the weight ratio of p-phenylenediamine to water is 4:6;

[0054] (2) Turn on the cooling water of the heat exchange coil and keep the reaction temperature at 100°C;

[0055] (3) When stirring at 100°C, continuously feed hydrogen into the primary hydrogenation reactor 5 and the secondary hydrogenation reactor 8; The pressure in the stage hydrogenation reactor 8 remains on 2.0MPa;

[0056] (4) When the hydrogen pressure in the kettle reaches 2.0MPa, continuously add water and p-nitroaniline into the primary hydrogenation reactor 5, and the speed of add...

Embodiment 3

[0061] Embodiment 3: produce p-phenylenediamine according to the following steps:

[0062] (1) In the first-stage hydrogenation reactor 5 and the second-stage hydrogenation reactor 8, first add a solution of p-phenylenediamine and water corresponding to 70% of the total volume of the reactor, and then add a solution equivalent to the above-mentioned p-phenylenediamine Amine and 0.5% nickel-based catalyst by weight of the aqueous solution; the weight ratio of p-phenylenediamine to water is 5:5;

[0063] (2) Turn on the cooling water of the heat exchange coil and keep the reaction temperature at 120°C;

[0064] (3) At 120°C under agitation, continuously feed hydrogen into the primary hydrogenation reactor 5 and the secondary hydrogenation reactor 8; The pressure in the stage hydrogenation reactor 8 remains on 2.0MPa;

[0065] (4) When the hydrogen pressure in the kettle reaches 2.0MPa, continuously add water and p-nitroaniline into the first-stage hydrogenation reactor 5, an...

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Abstract

The invention discloses a method and device for producing phenylenediamine by taking water as a solvent through a liquid phase continuous hydrogenation method. The method comprises the following steps of: adding a mixed solution of water and phenylenediamine into primary and secondary hydrogenation reaction kettles, adding a catalyst, and continuously introducing hydrogen into the primary and secondary hydrogenation kettles in a stirring state; after certain pressures are achieved in the primary and the secondary hydrogenation kettles, continuously adding water and a p-aromatic nitro compound into the primary hydrogenation reaction kettle, continually keeping the pressure in the primary and secondary hydrogenation kettles, discharging from the primary hydrogenation kettle to the secondary hydrogenation kettle, and continuously discharging from the secondary hydrogenation kettle; recovering the catalyst from a reaction liquid drained from the secondary hydrogenation kettle through a settling tank; and dehydrating the reaction liquid from which the catalyst is recovered by rectifying to obtain finished phenylenediamine. In the method and the device, water is taken as a solvent, so that solvent consumption and investment of equipment for recovering the solvent are saved, the production cost of the phenylenediamine is lowered, the operating safety is enhanced, and damages of a toxic solvent on operating personnel are avoided.

Description

technical field [0001] The invention relates to a production method and device for phenylenediamine, in particular to a method and a device for producing p-phenylenediamine, o-phenylenediamine, m-phenylenediamine and mixed phenylenediamine by using water as a solvent liquid-phase continuous hydrogenation method. Background technique [0002] Phenylenediamine includes p-phenylenediamine, o-phenylenediamine and m-phenylenediamine, which is one of the simplest aromatic diamines. P-phenylenediamine, o-phenylenediamine and m-phenylenediamine are widely used Intermediates, which can be used to prepare azo dyes, high molecular polymers, pesticides, medicines and other products. [0003] Domestic production methods of phenylenediamine mainly include iron powder reduction method, soda sulfide method, hydrogenation reduction method and other processes. Among them, the iron powder reduction method and the soda sulfide method are basically in the phase-out state due to large pollution...

Claims

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Application Information

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IPC IPC(8): C07C211/51C07C209/36
Inventor 杨宗高许如海王在良王武谦
Owner JIANGSU KESHENG CHEM MACHINERY
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