Method for synthesizing cyclohexylamine with aniline by means of gas-phase catalytic hydrogenation

A technology for catalytic hydrogenation and cyclohexylamine, applied in chemical instruments and methods, preparation of organic compounds, preparation of amino compounds, etc., can solve the problems of reducing side reactions, slowing reaction rate, increasing product yield, etc. Production safety and the effect of reducing side reactions

Active Publication Date: 2012-08-15
SHANDONG WEIJIAO GRP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The production technique of prior art also needs to be further optimized, and this is because: one, when reaction temperature is high, reaction rate becomes faster, and product output improves, but side reaction increases, product yield is lower, and when reaction tem

Method used

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  • Method for synthesizing cyclohexylamine with aniline by means of gas-phase catalytic hydrogenation
  • Method for synthesizing cyclohexylamine with aniline by means of gas-phase catalytic hydrogenation
  • Method for synthesizing cyclohexylamine with aniline by means of gas-phase catalytic hydrogenation

Examples

Experimental program
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Effect test

Embodiment 1

[0027] Mix fresh hydrogen with recycled hydrogen containing 1wt% ammonia, then mix the mixed hydrogen with aniline at a molar ratio of 19:1, and then add it to the aniline evaporator to vaporize the aniline, and the vaporized mixed gas is In the fixed-bed hydrogenation reactor pre-installed with catalyst, the catalytic hydrogenation reaction is carried out under the conditions of 165°C and 0.24MPa pressure, and the material after the hydrogenation reaction enters the separator for gas Separation to obtain crude cyclohexylamine, and then through rectification to obtain finished cyclohexylamine.

[0028] The gas separated in the separator is hydrogen containing ammonia, part of the mixed gas is used as circulating hydrogen, and the other part is continuously vented as tail gas; the step of continuous venting of tail gas is to conduct online detection of ammonia concentration in circulating hydrogen Finally, dynamically adjust the discharge of exhaust gas according to the detecti...

Embodiment 2

[0032] Mix fresh hydrogen with circulating hydrogen containing 2wt% ammonia, then mix the mixed hydrogen with aniline at a molar ratio of 18:1, and then add it to the aniline evaporator to vaporize the aniline. In the fixed-bed hydrogenation reactor pre-installed with catalyst, the catalytic hydrogenation reaction is carried out under the conditions of 170°C and 0.26MPa pressure, and the material after the hydrogenation reaction enters the separator for gas Separation to obtain crude cyclohexylamine, and then through rectification to obtain finished cyclohexylamine.

[0033] The gas separated in the separator is hydrogen containing ammonia, part of the mixed gas is used as circulating hydrogen, and the other part is continuously vented as tail gas; the step of continuous venting of tail gas is to conduct online detection of ammonia concentration in circulating hydrogen Finally, dynamically adjust the emission of tail gas according to the detection results, and then control the...

Embodiment 3

[0037] Mix fresh hydrogen with recycled hydrogen containing 6wt% ammonia, then mix the mixed hydrogen with aniline at a molar ratio of 16:1, and then add it to the aniline evaporator to vaporize the aniline. In the fixed-bed hydrogenation reactor pre-installed with catalyst, the catalytic hydrogenation reaction is carried out under the conditions of 175°C and 0.3MPa pressure, and the material after the hydrogenation reaction enters the separator for gas Separation to obtain crude cyclohexylamine, and then through rectification to obtain finished cyclohexylamine.

[0038] The gas separated in the separator is hydrogen containing ammonia, part of the mixed gas is used as circulating hydrogen, and the other part is continuously vented as tail gas; the step of continuous venting of tail gas is to conduct online detection of ammonia concentration in circulating hydrogen Finally, according to the test results, the discharge of exhaust gas is dynamically adjusted, and then the ammoni...

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Abstract

The invention discloses a method for synthesizing cyclohexylamine with aniline by means of gas-phase catalytic hydrogenation, which includes the steps: 1) mixing fresh hydrogen with circulating hydrogen; 2) mixing mixed hydrogen with the aniline according to the molar ratio of 15:1-19:1 in an aniline evaporator to enable vaporization of the aniline; 3) carrying out a hydrogenation reaction of vaporized mixed gas in a fixed bed hydrogenation reactor prefilled with cobalt-ruthenium catalyst or nickel-ruthenium catalyst at the reaction temperature of 165-179 DEG C and under the reaction pressureof 0.2-0.3MPa; and 4) materials which are subjected to the hydrogenation reaction enter a separator by means of heat exchange, condensation and cooling, performing gas separation to obtain crude cyclohexylamine, and then rectifying so that a cyclohexylamine product is prepared. By the aid of the method, production cost is effectively reduced, product yield is increased, and the service life of the catalyst is prolonged.

Description

technical field [0001] The invention relates to the technical field of cyclohexylamine synthesis methods, in particular to a method for synthesizing cyclohexylamine by gas-phase catalytic hydrogenation of aniline. Background technique [0002] Cyclohexylamine is an important chemical raw material and fine chemical intermediate. There are four main synthetic methods for it: aniline catalytic hydrogenation method, nitrocyclohexylamine reduction method, cyclohexanol catalytic ammonolysis method and cyclohexanone catalytic method. Ammonolysis method, among them, aniline catalytic hydrogenation method is divided into gas phase and liquid phase, and gas phase hydrogenation method is divided into normal pressure hydrogenation and high pressure hydrogenation from the process. Because the gas-phase atmospheric pressure catalytic hydrogenation method has the advantages of simple process, easy operation, high safety, readily available raw materials, and stable quality, it is currently ...

Claims

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Application Information

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IPC IPC(8): C07C211/35C07C209/72
Inventor 刘良玉王读升亓乐祥于海生刘春胜王读福
Owner SHANDONG WEIJIAO GRP
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