Continuous production method for tetrachloro terephthalonitrile

Abstract

The invention relates to a continuous production method of tetrachloroterephthalonitrile, comprising produce tetrachloroterephthalonitrile by gas phase chlorination catalyzing melting evaporated terephthalonitrile and chlorine in ebullated bed and fixed bed second-order series reactior, the concrete steps are: adding activated carbon catalyst of different requirement in ebullated bed and solid-bed reactor separately, dehydration by heating, filling excess chlorine for activating after dehydration finished; the melting evaporated terephthalonitrile, chlorine and nitrogen entering fluidized-bed reactor after mixed; the exit gas from ebullated bed entering solid-bed reactor, controlling the temperature of solid-bed reactor between 250-330deg C;The exit gas frim solid-bed reactor is chilled and separated by trap dyke, solid product tetrachloroterephthalonitrile enriched in the bottom of drip catcher. The technique is charactered with simple operation, less equipment invest, high yield, cleaning and good continuous operation. The product content is more than 98.0%,the tetrachlorobenzene content is 90%,the durability of catalyst is about 35 days.

Description

Technical field: [0001] The invention relates to a preparation method of tetrachlorophthalonitrile compounds, in particular to a continuous production method of tetrachloroterephthalonitrile. It belongs to the field of organic chemical technology. Background technique: [0002] Tetrachlorobenzenedicyano compounds have been widely concerned for a long time because of their very effective biological activity and can be used as fungicides and insecticides. The preparation of tetrachlorobenzenedicyanonitrile compounds is the earliest widely used liquid phase chlorination method. Mainly through the reaction of the corresponding tetrachlorophenylenediamine and chloric acid to form an amide, and the amide is dehydrated to obtain tetrachlorophthalonitrile, such as usp3,290,313. Later, with the research of gas-phase chlorination technology, various tetrachloroterephthalonitrile series compounds such as usp6, 034,264. [0003] The tetrachlorophthalonitrile compounds we are talking...

AI Technical Summary

Problems solved by technology

[0005] As we all know, the production process of tetrachloroisophthalonitrile is relatively mature, and the physical and chemical properties of tetrachloroterephthalonitrile are very different due to the influence of the para-position of the cyano group. The production process of isophthalonitrile

The main problem is that the raw material terephthalonitrile has a melting point of 222 ° C, which is 60 ° C higher than that of isophthalonitrile, and the melting temperature is relatively high, and it is sensitive to temperature, and high-temperature polymerization is prone to occur; the second is terephthalonitrile The chemical activity is less than that of isophthalonitrile, and the selectivity and specificity of the catalyst are relatively strict; the third is that the reaction yield is low, the product quality is poor, and the color is yellow

For a long time, it has been stuck in the stage of small laboratory tests, and has not been able to achieve industrial production in the true sense.

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