Production method of nitro compounds by tubular continuous nitrification reaction

Abstract

The invention relates to a production method of a chemical reaction process, and particularly relates to a production method of nitro compounds by tubular continuous nitrification reaction. The device comprises a tubular nitrification reactor, a tubular water-washing alkali-washing device, a nitrification mixture separator, and a water-washing alkali-washing separator. The nitrification raw materials and mixed acid flow, are mixed, react, and transfer heat in the tubular reactor; the separated nitro compounds are washed by water and alkali in a tubular manner to obtain qualified nitrification products; nitric acid is added from an inlet of the tubular nitrification reactor, or added respectively from the inlet and other parts of the tubular nitrification reactor. The production method for preparing nitro compounds by nitrification reaction provided by the invention realizes tubular continuous production, has high operation flexibility, high production efficiency, good product quality, few by-product, low energy consumption and raw material consumption, and safe and reliable production process. The invention is used for heat extraction nitrification and heat insulation nitrification.

Description

Technical field [0001] The invention relates to a production method for a chemical reaction process, in particular to a production method for preparing nitro compounds by nitration reaction. Background technique [0002] The nitration reaction is a reaction of introducing a nitro group into an aromatic ring, and the nitro compound of the reaction product is extremely versatile. The production of nitro compounds is to carry out the nitration reaction in the nitrification reactor first, and then separate the crude nitrate containing by-products such as nitrophenols from the nitrification waste acid, and the crude nitrate is washed with alkali to obtain the nitrated product. The nitrification reaction is divided into batch nitrification or continuous nitrification according to whether the production process is continuous, and according to whether the nitrification reaction heat is taken out during the reaction process, it is divided into thermal nitrification and adiabatic nitrifica...

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Problems solved by technology

When the kettle-type nitration reactor is used in the production process of heat-taking nitration reaction, the heat transfer is mainly through the outer jacket of the kettle. If the heat transfer of the jacket of the kettle-type nitration reactor cannot meet the requirements, a heat transfer coil must be installed in the kettle to increase the heat transfer. The addition of heat transfer coils will force the diameter of the stirring paddle to decrease, which will weaken the mixing effect and reduce the heat transfer coefficient. Therefore, the overall heat transfer effect of the tank-type nitration reactor is not good. When the tank-type nitration reactor is used for batch reactions, Generally, drop feeding is used, and local overheating of the feed site and uneven concentration distribution in the tank will occur, resulting in low product quality and limited production capacity; when the tank-type nitration reactor is used for continuous nitration reaction process, it is necessary to use multiple tanks in series , the residence time of the material in the kettle is uneven, the unnitrated and overnitrated substances are not easy to control in the production process, and the production process is complicated; there is a lot of material in the kettle-type nitration reactor, and once the reaction explosion is extremely destructive

In the current nitrification reaction technology, water washing and alkali washing also adopt multi-tank series operation, which also has the disadvantages of complicated operation control, poor washing effect, and high water and alkali consumption.

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