Method for preparing amine type products by hydrogenating nitro-compound

A technology for the preparation of nitro compounds and hydrogen, applied in the preparation of amino compounds, organic compounds, chemical instruments and methods, etc., can solve the problems of high content of by-products, achieve high selectivity, reduce back-mixing, and low probability of inactivation Effect

Active Publication Date: 2018-10-09
WANHUA CHEM GRP CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] BASF's patent US6350911 adopts a stirred tank reactor, and uses activated carbon (containing hydroxide) loaded Pt as a catalyst to carry out catalytic hydrogenation of nitrobenzene, and the heat of reaction is removed through heat exchange tubes arranged in the reactor. Although the process Improved reaction conversion, but still has the problem of high content of by-products (up to 1000ppm)

Method used

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  • Method for preparing amine type products by hydrogenating nitro-compound
  • Method for preparing amine type products by hydrogenating nitro-compound

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] Nitrobenzene is sent into stirred tank reactor 4 by nitrobenzene delivery pump 1 after being heated by nitrobenzene preheater 3, flow 65kg / hr; Water is sent into stirred tank reactor 4 by water delivery pump 2, water flow 55kg / hr; hydrogen was passed into the stirred tank reactor 4, with a flow rate of 1664 mol / hr; a Pt / Pd catalyst loaded with activated carbon was used in the reactor, and the concentration was 1 wt %. At a pressure of 17 bar and a temperature of 200 °C, nitrobenzene and hydrogen react in a stirred tank reactor to generate aniline and water.

[0036] The gas phase of the stirred tank reactor is discharged to the fixed bed reactor 5 to continue the reaction, and the liquid material is extracted at the flow rate of 0.6 kg / hr at the bottom of the stirred tank. Then continue to react. A copper-zinc-aluminum alloy catalyst (referring to patent CN106000408A for preparation method) is used in the fixed bed, and the filling amount is 0.8kg, and the hydrogenati...

Embodiment 2

[0039] Nitrobenzene is sent into stirred tank reactor 4 by nitrobenzene delivery pump 1 after being heated by nitrobenzene preheater 3, flow 65kg / hr; Water is sent into stirred tank reactor 4 by water delivery pump 2, water flow 55kg / hr; hydrogen was passed into the stirred tank reactor 4, and the flow rate was 1617 mol / hr; the reaction kettle adopted a Pt / Pd catalyst loaded with activated carbon, and the concentration was 0.2 wt%. At a pressure of 17 bar and a temperature of 250 °C, nitrobenzene and hydrogen react in a stirred tank reactor to generate aniline and water.

[0040] The stirred tank reactor gas phase is discharged to the fixed bed reactor 5 to continue the reaction, and the liquid material is extracted at the flow rate of 2kg / hr at the bottom of the stirred tank. Continue to react, adopt and adopt copper-zinc-aluminum alloy catalyst in fixed bed (referring to patent CN106000408A for preparation method), catalyst loading amount is 0.8kg, continue hydrogenation re...

Embodiment 3

[0043] Nitrobenzene is sent into stirred tank reactor 4 by nitrobenzene delivery pump 1 after being heated by nitrobenzene preheater 3, flow 65kg / hr; Water is sent into stirred tank reactor 4 by water delivery pump 2, water flow 55kg / hr; hydrogen was passed into the stirred tank reactor 4, and the flow rate was 1902 mol / hr; the reaction kettle adopted a Pt / Pd catalyst loaded with activated carbon, and the concentration was 5wt%. At a pressure of 17 bar and a temperature of 160 °C, nitrobenzene and hydrogen react in a stirred tank reactor to generate aniline and water.

[0044] The stirred tank reactor gas phase is discharged to the fixed bed reactor 5 to continue the reaction, and the liquid material is extracted by the flow rate of 2kg / hr in the stirred tank. Reaction, adopts copper-zinc-aluminum alloy catalyst (preparation method with reference to patent CN106000408A) in the fixed bed, the catalyst loading is 0.8kg, continues hydrogenation reaction under pressure 17bar, inl...

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Abstract

The invention provides a method for preparing amine type products by hydrogenating a nitro-compound. The method is realized through a continuous reaction system composed of a stirring kettle reactor and a fixed bed reactor; gas-phase discharged materials of the kettle reactor enter the fixed bed reactor to continually react; after less liquid phase at the bottom of the kettle is filtered to removea catalyst, the liquid phase also enters the fixed bed reactor to continually react. According to the method provided by the invention, two types of the reactors are matched and different active catalysts are used, so that the conversion rate of the nitro-compound can be greatly improved; meanwhile, adverse effects of excessive hydrogenation are extremely overcome.

Description

technical field [0001] The invention belongs to the field of hydrogenation synthesis, in particular to a method for preparing amine products by hydrogenation of nitro compounds. Background technique [0002] Aniline is an oily liquid that is widely used in the production of pharmaceuticals, pigments and rubber additives. At present, the catalytic hydrogenation of nitrobenzene is the main method for producing aniline, and the reaction process is shown as follows: [0003] [0004] The catalytic hydrogenation of nitrobenzene mainly includes two processes: gas phase hydrogenation and liquid phase hydrogenation. In the early days, gas-phase fixed-bed hydrogenation was mostly used. This process is easy to operate and does not need to separate catalysts. However, due to the limitation of heat transfer, it is difficult to enlarge it, and it is rarely used now. The subsequent liquid phase hydrogenation process is gradually emerging, wherein DuPont patent US4185036 discloses a s...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C211/46C07C209/36
CPCC07C209/36C07C211/46Y02P20/584
Inventor 薛勇勇乔小飞孙犀璨刘鹏于天勇员玫宋明焱刘俊贤赵一鸣贾峥瑞李金明贾海兵杨颖孙媛媛
Owner WANHUA CHEM GRP CO LTD
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