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Process for the production of dinitrotoluene

A technology of nitric acid and nitrated aromatics, applied in the preparation of nitro compounds, organic chemistry, etc., can solve the problems that cannot be realized

Active Publication Date: 2006-08-23
COVESTRO DEUTSCHLAND AG +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the goal of making the reaction as selective as possible and largely avoiding the formation of by-products cannot be achieved using only the above-mentioned reactors

Method used

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  • Process for the production of dinitrotoluene
  • Process for the production of dinitrotoluene

Examples

Experimental program
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Embodiment

[0028] The reaction of nitration of toluene to form dinitrotoluene was carried out according to the present invention in an experimental plant, wherein the process is shown in figure 2 middle. A mixture of 9.4% by weight of nitric acid, 71.5% by weight of sulfuric acid and 19.1% by weight of water was used as the nitrating acid. 5000 kg / h toluene stream with 36616 kg / h premixed nitrating acid figure 1 Mix in the mixing nozzle shown. The average flow rate of toluene in the mixing nozzle tubular reactor was 5 m / s. The average flow velocity of the nitrifying acid in the annular gap of the mixing nozzle was 2.2 m / s. Nitrification was carried out in Reactor 1 with a cooling water temperature of about 35°C and Reactor 2 with a cooling water temperature of 65°C. Mixing nozzles are used in Reactor 1 .

[0029] In a comparative example (ie, not representing an example of the present invention), nitrating acid and toluene were added to the reactor in the same proportions, but were...

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Abstract

The present invention is directed to a process for the isothermal nitration of aromatic organic compounds, wherein an aromatic organic compound is brought into contact and reacted with a mixture of sulfuric acid and nitric acid. The mixture of sulfuric acid and nitric acid, and the aromatic organic compound are brought into contact with each other through a mixing nozzle which comprises a substantially cylindrical tubular reactor and an annular gap which surrounds the tubular reactor. The aromatic organic compound flows through the tubular reactor, and the mixture of sulfuric acid and nitric acid flows through the annular gap, and they are mixed together upon emerging from the tubular reactor and the annular gap, wherein the ratio of the average rates of flow of the aromatic organic compound in the tubular reactor, and of the mixture of sulphuric acid and nitric acid in the annular gap ranges from 0.5:1 to 10:1.

Description

technical field [0001] The present invention relates to a process for the nitration of aromatic organic compounds in the liquid phase, wherein the aromatic organic compounds are vigorously mixed with a mixture of nitric acid and sulfuric acid in a mixing nozzle and then added to a reaction capable of active mixing in the device. During the course of this process, dinitrotoluene is produced from toluene. Background technique [0002] Dinitrotoluene (DNT) is an intermediate in the production of toluene diisocyanate (TDI). DNT can be produced on an industrial scale by nitrating toluene with nitric acid in the presence of sulfuric acid (see, Ullmann's Encyclopedia of Industrial Chemistry, 6th edition, 2003, Wiley). However, the disadvantage of this method is that waste water is often generated, which must be purified before being discharged into surface water. The cost of purifying these wastewaters is quite high. [0003] Therefore, it is an object of the present invention ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C201/08C07C205/06C07C205/21
CPCC07C205/06C07C201/08
Inventor J·穆宁B·彭尼曼D·瓦斯蒂昂V·米谢勒J·卡拉瓦焦J·F·吉斯奇
Owner COVESTRO DEUTSCHLAND AG