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Method for preparing m-phenylenediamine through catalytic hydrogenation of 2,4-dinitrochlorobenzene

A technology of dinitrochlorobenzene and m-phenylenediamine, which is applied in the field of catalytic hydrogenation of 2,4-dinitrochlorobenzene to prepare m-phenylenediamine, which can solve the problems of excessive three wastes, harsh reaction conditions, and equipment corrosion. To achieve the effect of applying more batches, high conversion rate and yield, and less usage

Inactive Publication Date: 2019-08-16
济南和润化工科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] The technical problem to be solved by the present invention is that the existing two-step preparation method of m-phenylenediamine has defects such as harsh reaction conditions, serious equipment corrosion, many wastes, serious environmental pollution, and low product purity or production capacity. phenylenediamine method

Method used

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  • Method for preparing m-phenylenediamine through catalytic hydrogenation of 2,4-dinitrochlorobenzene

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] A kind of preparation method of m-phenylenediamine, take 2,4-dinitrochlorobenzene as raw material, adopt 3% palladium carbon catalyst, use sodium carbonate as acid-binding agent, carry out catalytic hydrogenation reaction in 5000L hydrogenation reactor At the end of the reaction, an appropriate amount of water is added, the catalyst is separated and recovered, the reducing solution is precipitated, and purified to obtain the target product m-diamine.

[0028] Specific steps:

[0029] (1) Add 3000L of methanol, 1000kg of 2,4-dinitrochlorobenzene, 252kg of sodium carbonate, and 10kg of 5% palladium-carbon catalyst into a 5000L hydrogenation reactor. After three times of nitrogen replacement, three times of hydrogen replacement, and After the oxygen content of the hydrogen gas is detected to be qualified, 0.8Mpa of hydrogen gas is introduced to carry out the catalytic hydrogenation reaction, and the reaction temperature is controlled at 80°C.

[0030] (2) After reacting f...

Embodiment 2

[0033] (1) Add 3000L of methanol, 1000kg of 2,4-dinitrochlorobenzene, 252kg of sodium carbonate, and 10kg of 3% palladium-carbon catalyst into a 5000L hydrogenation reactor, undergo three times of nitrogen replacement, three times of hydrogen replacement, and After detecting that the oxygen content of hydrogen gas is qualified, 1.0Mpa of hydrogen gas is introduced to carry out catalytic hydrogenation reaction, and the reaction temperature is controlled at 90°C.

[0034] (2) After reacting for 5 hours, close the hydrogen valve, and the hydrogen pressure no longer drops. After chromatographic detection, 2,4-dinitrochlorobenzene has been completely converted (the content of 2,4-dinitrochlorobenzene is 0), m-phenylene The crude amine content was 99.26%, so it was judged that the reaction was finished. Under stirring, the temperature of the reaction solution is lowered to below 50°C, 500kg of water is added once, and nitrogen is filled to press the material. The material liquid pas...

Embodiment 3

[0037] (1) Add 3,000L of methanol, 1,000kg of 2,4-dinitrochlorobenzene, 252kg of sodium carbonate, and 1kg of 3% palladium carbon catalyst to a 5,000L hydrogenation reactor. After three times of nitrogen replacement and three times of hydrogen replacement, After the oxygen content of the hydrogen gas is detected to be qualified, 1.0Mpa of hydrogen gas is introduced to carry out the catalytic hydrogenation reaction, and the reaction temperature is controlled at 90°C.

[0038] (2) After reacting for 4 hours, close the hydrogen valve, and the hydrogen pressure no longer drops. After chromatographic detection, 2,4-dinitrochlorobenzene has been completely converted (the content of 2,4-dinitrochlorobenzene is 0), m-phenylene The content of crude amine was 99.3%, so it was judged that the reaction was finished. Under stirring, the temperature of the reaction solution is lowered to below 50°C, 500kg of water is added once, and nitrogen is filled to press the material. The material liq...

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Abstract

The invention discloses a method for preparing m-phenylenediamine by taking 2,4-dinitrochlorobenzene as a raw material. The method comprises the following steps: with 2,4-dinitrochlorobenzene as a rawmaterial, methanol as a solvent, an alkaline substance as an acid-binding agent and precious metal palladium / carbon as a catalyst, feeding hydrogen for catalytic hydrogenation to obtain m-phenylenediamine. The method is simple to operate and high in safety, and can achieve the effects of high production efficiency, high product quality, low labor intensity, environmental friendliness, high catalyst utilization rate, benefit to industrialization and the like.

Description

technical field [0001] The invention belongs to the field of catalytic hydrogenation in chemical production, and in particular relates to a method for preparing m-phenylenediamine by catalytic hydrogenation of 2,4-dinitrochlorobenzene. Background technique [0002] M-phenylenediamine, also known as 1,3-diaminobenzene, is a white needle-like crystal. It is an important organic chemical raw material and intermediate, and is widely used in industries such as dyes, washing chemicals, rubber, and national defense. Due to the strong coupling ability of m-phenylenediamine, azo dyes, fur dyes, reactive dyes and sulfur dyes can be produced in the dye industry, and it is also used to produce hair dyes, petroleum additives, rubber antioxidants, etc. It is widely used in various fields. [0003] The traditional method of producing m-phenylenediamine: [0004] Using nitrobenzene as raw material, meta-dinitrobenzene is obtained through nitration and refining. In addition to m-dinitroben...

Claims

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Application Information

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IPC IPC(8): C07C211/51C07C209/36
CPCC07C209/36C07C211/51
Inventor 侯卫波韩龙凯王超李娟
Owner 济南和润化工科技有限公司
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