Method for preparing aniline from nitrobenzene

A technology of nitrobenzene and aniline, which is applied in the field of preparing aniline from nitrobenzene, can solve problems such as inability to preserve, large amount of reaction by-products, and changes in catalytic activity, achieving obvious cost advantages and simplifying the production process

A technology of nitrobenzene and aniline, which is applied in the field of preparing aniline from nitrobenzene, can solve problems such as inability to preserve, large amount of reaction by-products, and changes in catalytic activity, achieving obvious cost advantages and simplifying the production process

CN101434547AInactive Publication Date: 2009-05-20甘肃中科药源生物工程股份有限公司
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Examples

Experimental program
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Effect test

Embodiment

[0012] Embodiment: the method for preparing aniline by catalytic hydrogenation of nitrobenzene

[0013] First add 100 grams of nitrobenzene in the reaction kettle, then add 20% of the nitrobenzene mass concentration and be 95% ethanol, then add a supported catalyst with 3 to 6% nitrobenzene mass, close the reaction kettle, and use Hydrogen completely replaces the air in the reactor, then keeps the reactor at normal pressure (about 0.1MPa), and starts heating and stirring. After the temperature reaches 60°C, hydrogen is introduced into the reactor to keep the pressure inside the reactor at 1.0-3.0MPa ( The test shows that the optimum pressure should be about 1.5MPa), and the hydrogenation reaction starts. During the hydrogenation process, the temperature in the kettle is kept in the range of 60-90°C. After about 3 to 8 hours of hydrogenation, the conversion rate reaches 95%- More than 99%, separate out reaction mixture and catalyzer then, the catalyzer that separates returns re...

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Abstract

The invention discloses a method for preparing aniline by using nitrobenzene, which comprises the steps as follows: nitrobenzene, ethanol and a supported catalyst are respectively added into a kettle firstly, wherein, the mass of the ethanol added is 10 percent to 30 percent of that of the nitrobenzene added and the mass of the supported nickel catalyst is 3 percent to 6 percent of that of the nitrobenzene added; hydrogenation reaction is carried out at the temperature of 60 DEG C to 90 DEG C for 3 hours to 8 hours and the pressure for the hydrogenation reaction is 1.5 MPa to 3.0 MPa; solid-liquid separation is carried out after the completion of the reaction; product separation is carried out to a supernatant solution separated; and a solid catalyst separated is input into the reaction system for continuous use again.

Description

technical field [0001] The invention relates to a method for preparing aniline from nitrobenzene. Background technique [0002] The reduction of nitro compounds to amino compounds was first prepared by the method of iron powder and hydrochloric acid. This method is seriously polluting, and it is a process route that will be abolished in the near future as stipulated by the state. In recent years, most of this kind of production uses Raney nickel catalysts. , that is, the conversion of nitro to amino groups is realized by catalytic hydrogenation using Raney nickel as a catalyst, but the use of Raney nickel catalysts for catalytic hydrogenation has the following disadvantages: [0003] 1) It is extremely inconvenient to use. Because the active component of the Raney nickel catalyst for catalytic hydrogenation is skeleton nickel, but skeleton nickel is extremely easy to catch fire in the air and cannot be stored. It can only be used as a commodity in the form of nickel-aluminu...

Claims

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Application Information

Patent Timeline
20 May 2009
Publication
CN101434547A
IPC
C07C211/45; C07C209/36
Inventors
马建泰; 常青