Safe production method of nitro-compound

Abstract

The invention provides a production method of nitro-compound. The production method comprises the steps of: continuously feeding a mixed acid solution from a heavy-phase inlet of a first centrifugal extraction separation device of a nitration separation system disclosed by the invention, and continuously feeding a raw material to be nitrified from a light-phase inlet of a final centrifugal extraction separation device at the same time, wherein the reaction temperature inside each centrifugal extraction separation device is controlled at 10-160 DEG C, and the rotating speed of each centrifugal extraction separation device is controlled at 800-2000 r / min; after multi-stage continuous nitration reaction, discharging final coarse nitride from a light-phase outlet of the first centrifugal extraction separation device, and discharging final waste acid from a heavy-phase outlet of the final centrifugal extraction separation device; and carrying out common alkali washing and water washing on the coarse nitride, and distilling the coarse nitride to obtain the refined nitro-compound product. According to the method disclosed by the invention, the nitration reaction is continuously carried out; the device is compact, easy to achieve automatic control, large in operation elasticity, and high in production efficiency; and as the reaction product and the waste acid are separated from each other at the same time inside the same reactor, the contact time of the reaction product and the waste acid is greatly shortened, side reaction is effectively avoided, energy consumption and material consumption are greatly reduced, and the security of the nitration reaction process is fundamentally ensured.

Description

technical field [0001] The invention belongs to the technical field of synthesizing nitrate-based compounds through nitration reaction of hydrocarbon compounds and nitric acid under the action of an acid catalyst, and specifically relates to a production device and production method for preparing nitro-compounds through nitration reaction. Background technique [0002] Nitration reaction is a chemical reaction in which nitro groups are introduced into hydrocarbon compounds, especially aromatic hydrocarbon compounds, to generate nitro compounds. Nitro compounds have a wide range of uses. The production of nitro compounds has long been produced by using mixed acid as a nitrating agent. Firstly, the nitration reaction is carried out in the nitration reactor, and then the crude nitration product is separated from the waste acid after nitration, and the crude nitration product is washed with water and alkali to obtain the nitration product. The nitrification reaction can be divi...

AI Technical Summary

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 carried out through the outer jacket of the kettle. If the jacket of the kettle-type nitration reactor cannot meet the requirements, it is necessary to install a heat transfer coil in the kettle to increase the heat transfer area. The diameter of the agitator is forced to be reduced by adding a heat transfer coil, which weakens the mixing effect and reduces the heat transfer coefficient, so the overall heat transfer effect of the tank-type nitration reactor is not good; when the tank-type nitration reactor is used for intermittent nitration reactions, generally If the feed is added dropwise, 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 an explosion occurs, it will be extremely destructive

[0003] Chinese patent CN102432410A and Chinese patent CN1789235A propose a tubular nitration reactor, using a static mixer as a nitration reactor, so that the mixed acid and the raw material to be nitrated flow, mix, react and transfer heat in the tubular reactor , although this kind of nitration reactor has a certain progress compared with the tank-type nitration reactor, the reaction materials enter from the same side of the tubular reactor and flow out from the other side together. As the flow and reaction proceed, the distance between the reaction materials The farther the material is imported, the lower the concentration of the reactant and the higher the concentration of the product, the smaller the driving force of the reaction, which may lead to incomplete reaction or increase the probability of side reactions; in addition, special separation is required after the reaction is completed. The equipment separates the nitration products and waste acid, and the operation is relatively complicated

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