Production method of benzonitrile

Abstract

A producing method of benzonitrile is provided, comprising contacting the air with the mixing gas of toluene and ammonia in a fluidized bed reactor and reacting in a toluene ammoxidation method which is catalyzed by fine grain catalyzer with high activity in a reacting temperation of 410-420 DEG C and producing the gaseous benzonitrile and water, cooling and condensating them in the collection tower and absorption tower to be benzonitrile and water, removing the water layer, decompressing and distilling to obtain the transparent liquid pure benzonitrile. The invention has a simple production progress, a continuous production, a reliable product quality, a high product purity up to 99.6-99.8%, a low moisture content down to 0.02% and a good yield of 64-81%.

Description

technical field [0001] The present invention relates to the production method of benzonitrile. Background technique [0002] Benzonitrile has a wide range of applications, and its biggest use is that the benzomelamine produced by the reaction with dicyandiamide can be used in metal coatings, plastics, fluorescent pigments, molding materials, etc. Benzonitrile can also be used in organic synthesis, paints, High-boiling solvents for printing inks and resins, additives for jet engine fuels, and combustion aids for synthetic fibers. The market demand is increasing year by year. [0003] According to foreign data, it was Japan that first realized the industrialization of aromatic nitriles produced by toluene ammoxidation. In 1963, Nitto Chemical Industry Co., Ltd. produced 2,6-dichlorobenzonitrile by ammoxidation of 2,6-dichlorotoluene based on self-developed catalyst and fluidized bed reaction process. In 1969, Japan Catalyst Chemical Industry Co., Ltd. used the ammoxidation ...

AI Technical Summary

Problems solved by technology

[0005] 1. Coarse particle catalyst fluidization technology is commonly used in production plants. The carrier of coarse particle catalyst is alumina, and the active components are mainly metal vanadium and chromium. The sieving range is 40-120 mesh, specific surface and specific pore volume small, poor mechanical strength

Coarse particle catalyst itself has poor activity, selectivity, and stability, resulting in low levels of conversion and yield

Moreover, the service life of the catalyst is short, and the activity will be lost in a short period of time, so the catalyst must be removed for regeneration

[0006] 2. In the reactor, the contact between the reaction material gas and the solid catalyst is uneven, and the large bubbles generated by the coarse particle catalyst often appear channeling, throttling, etc., which affect the fluidization quality

And the material gas stays in the bed for too long, causing secondary reactions and aggravating the deterioration of the process

[0007] 3. The distillation method adopts atmospheric distillation, and the temperature is high, so that the product purity has been hovering between 98%-99%, which cannot be improved

[0008] The product yield of the above-mentioned production process is low, the material consumption and energy consumption are high, the environmental pollution is serious, and the product purity cannot meet the user's requirements

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