Method and device for producing mono-nitro toluence by adiabatic nitration through self-mixing tubular reactor

Abstract

The invention relates to a method and a device for producing mono-nitro toluence by adiabatic nitration through a self-mixing tubular reactor. The method comprises the steps that: reaction raw materials, namely toluence, dilute nitric acid and a catalyst (sulfuric acid), are pumped into the self-mixing tubular reactor and are subjected to full exothermic reaction after self mixing; the materials after the reaction enter a static-state-phase separator for phase splitting; organic phases obtained by phase splitting enter a subsequent purification unit for purification; the lower-layer materials obtained by the purification enter a sulfuric acid concentrator; sulfuric acid which is concentrated by reaction heat re-enters the self-mixing tubular reactor for circulation. According to the method and the device, the self-mixing tubular reactor is adopted, so that the sufficient mixing and reaction of the materials can be realized without additionally arranging any mixer or rotation equipment; the dilute nitric acid is used as the reaction material, so that the nitric acid concentration step is eliminated, the flow is simplified, and the production cost is reduced; simultaneously the dilute sulfuric acid is concentrated by the reaction heat, so that the energy consumption is greatly reduced, and the concept of energy saving and consumption reduction is met.

Description

technical field [0001] The invention relates to a method and a device for producing mononitrotoluene by adiabatic nitration in a self-mixing tubular reactor. Background technique [0002] Mononitrotoluene (also known as mononitrotoluene) has three isomers, ortho, meta, and para, which are widely used in pesticides, medicines, dyes, plastics and other fields, and their derivative products are also increasing Therefore, the demand in the market has been rising steadily. With the continuous development of newer and more efficient dyes and pesticides, mononitrotoluene is showing vigorous vitality. [0003] The nitration reaction of toluene is a liquid-liquid heterogeneous fast reaction controlled by mass transfer, which releases a large amount of reaction heat in a relatively short period of time. The water generated by the reaction dilutes the catalyst concentrated sulfuric acid and generates dilution heat at the same time. If the heat cannot be removed in time, it will Lead ...

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Problems solved by technology

[0004] Aiming at the shortcomings of mononitrotoluene production process equipment such as large footprint, low production efficiency, high energy consumption, and high investment costs, the present invention provides a method and device for producing mononitrotoluene by adiabatic nitration in a self-mixing tubular reactor. The coupling of static mixing and tubular reaction is carried out in one device, which not only takes advantage of the advantages of high efficiency, low energy consumption, small volume, low investment, and easy continuous production of the static mixer, but also takes advantage of the small backmixing and The advantage of high volumetric efficiency; in addition, the existing isothermal nitrification is replaced by adiabatic nitrification, and the heat of reaction and dilution heat are fully utilized; moreover, the use of dilute nitric acid instead of concentrated nitric acid saves nitric acid concentration units, simplifies the process, and greatly reduces energy consumption

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