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Method for producing methylaniline from nitrotoluene through liquid-phase hydrogenation reduction

A technology of nitrotoluene liquid and methylaniline, which is applied in the field of nitrotoluene liquid-phase hydrogenation reduction to produce methylaniline, can solve the problems of poor product quality, low yield, short storage time, etc., and is easy to achieve Operation management, high yield and good product quality

Inactive Publication Date: 2012-04-04
JIANGSU FIRST CHEM MFG
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The production indicators of this method, such as temperature and pressure, require high control, the product quality is not good enough, the storage time is also short, the yield is not too high, the consumption is large, and there are problems such as high operating costs.

Method used

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  • Method for producing methylaniline from nitrotoluene through liquid-phase hydrogenation reduction
  • Method for producing methylaniline from nitrotoluene through liquid-phase hydrogenation reduction

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] Embodiment 1: through pipeline to volume is 5m 3 In the reaction kettle, add 2000Kg of methanol as a solvent, and at the same time add the expanded Raney nickel catalyst through the pipeline, add 40Kg when starting up for the first time, and only need to add 2Kg to each kettle when it is in normal production. Adjust the outlet pressure of the machine to 1.0MPa to completely replace the air in the reactor, start the stirring motor, control the rotation speed to 320r.p.m to raise the temperature, and when the temperature of the reactor is heated to 55°C, use a metering pump to pass the purity test through the pipeline. Gradually add 2000Kg m-nitrotoluene with not less than 99% into the kettle to start the reaction; turn off the heating steam, open the cooling water valve, and control the temperature at 80-90°C. After 3-4 hours of reaction, when the pressure of the reactor rises, the temperature When it stops rising, it means that the reaction has basically ended; at this ...

Embodiment 2

[0014] Embodiment 2: through pipeline to volume is 5m 3 In the reactor, add 2000Kg of solvent methanol, and at the same time add the Raney nickel catalyst through the pipeline, add 45Kg when starting up for the first time, and only need to add 2Kg to each kettle when it is in normal production, feed hydrogen through the pipeline, and pressurize the hydrogen Adjust the outlet pressure of the machine to 1.1MPa to completely replace the air in the reactor, start the stirring motor, control the rotation speed to 330r.p.m, and raise the temperature. When the temperature of the reactor is heated to 55°C, use a metering pump to pass the purity test through the pipeline. Gradually add 2000Kg p-nitrotoluene with not less than 99% into the kettle to start the reaction; turn off the heating steam, open the cooling water valve, and control the temperature at 80-90°C. After 3-4 hours of reaction, when the pressure of the reactor rises, the temperature When it stops rising, it means that th...

Embodiment 3

[0015] Embodiment 3: through pipeline to volume is 5m 3 In the reactor, add 2000Kg of methanol as a solvent, and at the same time add the expanded Raney nickel catalyst through the pipeline. When starting up for the first time, add 50Kg. When it is in normal production, you only need to add 2Kg to each kettle. Adjust the outlet pressure of the machine to 1.2MPa, after completely replacing the air in the reactor, start the stirring motor and control its speed to 345r.p.m to raise the temperature. When the temperature of the reactor is heated to 55°C, use a metering pump to pass the inspection through the pipeline. 2000Kg o-nitrotoluene with a purity of not less than 99% is gradually added to the kettle to start the reaction; turn off the heating steam, open the cooling water valve, and control the temperature at 80-90°C. After 3-4 hours of reaction, when the pressure of the reactor rises, When the temperature no longer rises, it indicates that the reaction has basically ended; ...

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Abstract

The invention discloses a method used for producing methylaniline from nitrotoluene through liquid-phase hydrogenation reduction. The production method of methylaniline comprises steps of feeding reduction and pressure-reducing separation. In the feeding reduction process, methanol, a Raney nickel catalyst, hydrogen and nitrotoluene are added to a reaction vessel; under the existence of both the solvent methanol and the catalyst, a liquid-phase catalyzed hydrogenation reaction is carried out, such that nitrotoluene is produced. According to the invention, the controlling requirements of production indexes such as temperature and pressure are low, and the method is advantaged in easy operation and management, high equipment automatic control level, good product quality, high yield, low energy consumption, recoverable catalyst and methanol, low wastewater generation, low tar, good environmental benefit, low operation cost, and high adaptability. The method can be used in reduction reactions of o-, m- or p-nitrotoluene for producing o-, m- or p-methylaniline.

Description

technical field [0001] The invention relates to a production method of methylaniline, in particular to a method for producing methylaniline by liquid-phase hydrogenation reduction of nitrotoluene. Background technique [0002] In the prior art, the reduction of nitrotoluene to methylaniline adopts the iron powder reduction method, which is relatively mature, but it contains a large amount of amine iron sludge in the production process and cannot be processed. The other is the solvent-free hydrogenation reduction method. In the presence of a catalyst, but without any solvent, nitrotoluene can react with hydrogen. After the reaction is completed, the mixed solution and the catalyst are filtered, left standing or dynamically separated. The catalyst Recycling and reuse, and the crude methylaniline can be obtained after separation, dehydration and rectification. The method requires high control of production indicators such as temperature and pressure, the product quality is not...

Claims

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Application Information

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IPC IPC(8): C07C211/47C07C209/36
Inventor 管政
Owner JIANGSU FIRST CHEM MFG
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