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Nitration method of aromatic hydrocarbon compound

A technology for aromatic hydrocarbon compounds and nitric acid, applied in the field of nitrification of aromatic hydrocarbon compounds, can solve the problems of waste of resources, long reaction time, instability, etc., and achieve the effects of operator safety, reduction of workshop material storage, and less waste acid wastewater.

Active Publication Date: 2019-11-29
江苏方圆芳纶研究院有限公司
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  • Abstract
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  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Zhou Shenghui studied the preparation of aromatic nitro compounds by NO2 liquid-phase catalyzed nitration of aromatic hydrocarbons. Under the catalysis of FeCl3, the molar ratio of benzene to NO2 was 1:5, and the reaction temperature was 100℃ , the reaction time is 4 hours, and the catalyst addition amount is 0.06 grams, which is the best reaction condition. At this time, the conversion rate of benzene reaches 99%, and the selectivity of nitrobenzene reaches 99%. In this process, a large amount of NO is added in the benzene nitration reaction. 2, NO2 after the reaction is difficult to recycle, which is easy to cause waste of resources and environmental pollution
In addition, direct nitrification using nitrogen oxides (such as NO2) has certain instability and long reaction time, which is subject to certain restrictions in actual production

Method used

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  • Nitration method of aromatic hydrocarbon compound
  • Nitration method of aromatic hydrocarbon compound
  • Nitration method of aromatic hydrocarbon compound

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] like figure 1 Shown, a kind of nitration method of aromatic compound comprises the following steps:

[0039] 1) In the reactor 1 having a temperature-measuring reflux device and band stirring, at first drop into 15.6 grams of solid acid catalyst, then add 312.4 grams of aromatic compound in reactor 1 through the aromatic compound feeding pipe 3, and pass through the liquid dioxygen tetraoxide Nitrogen feed pipe 4 drips 202.4 grams of liquid dinitrogen tetroxide in reactor 1, simultaneously feeds 32 grams of oxygen into reactor 1 by bubbling oxygen-containing flow inlet 5, and controls reaction pressure at 6MPa, temperature at 50°C;

[0040] 2) while step 1) is carried out, dropwise the sulfuric acid of 59.2 grams of 95% in reactor 1 by sulfuric acid feed pipe 2;

[0041] 3) The material obtained from the liquid outlet 7 enters the separator 8, and the aqueous phase material 9 and the organic phase material 10 are obtained through liquid separation treatment, and the s...

Embodiment 2

[0046] The reaction steps are the same as in Example 1, except that in step 2), 8.7 grams of nitric acid with a concentration of 65% and 59.2 grams of 95% sulfuric acid are configured into a mixed acid and then added to the reactor 1 together.

[0047] The average residence time of the reactants was 1.4 hours, and the yield of nitrobenzene was 95.9% based on benzene. After the catalyst was used continuously for 20 times, the yield of nitrobenzene was 94.34% based on benzene; after the catalyst was used continuously for 40 times, the catalyst still maintained good catalytic activity, and the yield of nitrobenzene was 92.8% based on benzene.

Embodiment 3

[0049] The reaction steps are the same as in Example 1, except that 5.6 grams of water and liquid dinitrogen tetroxide are dropped into the reactor 1 simultaneously in the step 1), and the addition of process conditions and other substances is also the same as in Example 1.

[0050] The average residence time of the reactants was 1.9 hours, and the yield of nitrobenzene was 95.72% based on benzene. After the catalyst was used continuously for 20 times, the yield of nitrobenzene was 93.72% based on benzene; after the catalyst was used continuously for 40 times, the catalyst still maintained good catalytic activity, and the yield of nitrobenzene was 90.03% based on benzene.

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Abstract

The invention relates to a nitration method of an aromatic hydrocarbon compound, in particular to a method for preparation of a nitro aromatic hydrocarbon compound by subjecting an aromatic hydrocarbon compound to nitration reaction with liquid dinitrogen tetroxide and oxygen-containing air flow in the presence of a solid acid catalyst and a small amount of sulfuric acid. And the method is a production process suitable for industrialization.

Description

technical field [0001] The application relates to a method for nitrating aromatic compounds, in particular to a method for nitrating aromatic compounds by introducing nitrogen oxides in the presence of a small amount of sulfuric acid. Background technique [0002] Nitration products of aromatic compounds are important fine chemical intermediates, which can be widely used in dyes, medicines, pesticides and explosives. At present, the industry still adopts the traditional process of nitration under certain reaction conditions with benzene and nitric acid as raw materials and sulfuric acid as a catalyst. The disadvantage of this process is that it will produce a large amount of waste acid and waste water that needs to be treated; during the process operation, the substrate is added to the prepared mixed acid, and excessive mixed acid is likely to produce polynitro by-products; The heat is above 100kJ, and the specific heat capacity of sulfuric acid is very small. The temperatu...

Claims

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Application Information

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IPC IPC(8): C07C201/08C07C205/06C07B43/02
CPCC07C201/08C07B43/02C07C205/06Y02P20/52
Inventor 王农跃沙艳松章冬霞李斌许坚王伟王承梁朱洪杰
Owner 江苏方圆芳纶研究院有限公司
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