Solid-liquid separation process for preparing isophthalodinitrile

Abstract

The invention discloses a solid-liquid separation process for preparing isophthalodinitrile. The process comprises the following steps that: after being cooled by an oil cooler, a mixed gas at the outlet of a fluidized bed reactor enters from a first-grade water sprayer, and the mixed gas at the outlet of the first-grade water sprayer enters from the bottom of a second-grade water sprayer and then is discharged from the top of the second-grade water sprayer; and solid-liquid mixtures in the first-grade water sprayer and the second-grade water sprayer enter a settling tank to be settled, the slurry of isophthalodinitrile at the relatively high concentration at the bottom of the settling tank enters a centrifuge, and the material at the outlet of the centrifuge enters drying equipment to bedried finally. The solid-liquid separation process reduces working environment of workers, improves the working efficiency and increases the quality and yield of phthalodinitrile.

Description

Technical field: [0001] The invention relates to a solid-liquid separation process for preparing isophthalonitrile. Background technique: [0002] Isophthalonitrile (abbreviated as IPN) is an important organic raw material for organic synthesis. Tetrachloroisophthalonitrile (i.e., chlorothalonil) synthesized by chlorination is an efficient and low-toxic fungicide; M-xylylenediamine is an epoxy resin curing agent with superior performance, and it is also a raw material for polyurethane resin and nylon resin. [0003] The simplest and most economical way to produce isophthalonitrile is to obtain it by gas-phase ammoxidation of m-xylene under the action of a catalyst. In terms of the material collection method, the box-type series indirect cooling collection originally used in China is then washed and filtered with clean water, and dried to obtain the product. This capture method is labor-intensive and the operating environment is harsh. At the same time, because the heat exc...

AI Technical Summary

Problems solved by technology

This patent uses a filter press to separate the solid-liquid mixture. The filter press is an intermittent device and cannot be operated continuously with subsequent drying equipment.

Because the isophthalonitrile particles will have viscosity after soaking in water, the viscosity of the material will increase when the material stays in the filter press for a long time, so that the material after the filter press is not easy to fall off the filter plate, which will cause the filter cloth to be blocked. Mechanical impurities and other impurities in the material will also block the filter cloth, which will greatly reduce the service life of the filter cloth

Since the filter press is not operated in a closed manner, ammonia gas escapes during operation, which has a great impact on the working environment of workers

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