Preparation method of tetrachloro-terephthalonitrile with low hexachlorobenzene content

Abstract

The invention discloses a preparation method of tetrachloro-terephthalonitrile with low hexachlorobenzene content. The preparation method comprises the following steps: putting metered para-phthalonitrile into a vaporizer, performing vaporization, taking m-phthalonitrile out of the vaporizer along with nitrogen after vaporizing the m-phthalonitrile, mixing the m-phthalonitrile and chlorine duringmixing, and sequentially entering a fluidized bed and a fixed bed with special chlorination catalysts to perform reaction. The molar ratio of the gas inlet quantities of the para-phthalonitrile to thenitrogen to the chlorine is equal to 1:(6-7):(4-5), the reaction temperature of the fluidized bed and the reaction temperature of the fixed bed are controlled to be 300 to 320 DEG C and 340 to 350 DEG C correspondingly, the pressure is controlled to be 0.002 to 0.005 MPa, the reaction mixed gas is fed into a material receiver after the reaction, and condensation drying is conducted to obtain thetetrachloro-terephthalonitrile with low hexachlorobenzene content.

Description

technical field [0001] The invention belongs to the technical field of chemical production and relates to a preparation method of a chemical intermediate tetrachloroterephthalonitrile. Background technique [0002] Tetrafluoroterephthalonitrile is an important organic intermediate with a white powder appearance, which is further synthesized into tetrafluoroterephthalonitrile by fluorination, and tetrafluoroterephthalonitrile is an important fluorine-containing Aromatic chemical intermediates, widely used in the synthesis of medicines, pesticides, dyes and fluoropolymers. Using them to synthesize pesticides has strong selectivity, less usage, low toxicity to humans, and low residues. It has broad development prospects, high value, and good market prospects. Thereby tetrachloroterephthalonitrile as the raw material for producing tetrafluoroterephthalonitrile has received extensive attention for a long time. [0003] CN200610038423.8 discloses a kind of method of industrializ...

AI Technical Summary

Problems solved by technology

This process is a four-step reaction, which adopts batch production, and there are many reaction intermediate products. At the same time, a large amount of acid-containing wastewater is generated and a large amount of solvent is used in the preparation process, so there are many three wastes in the production process, which is not conducive to environmental protection.