Method for inhibiting the degradation of phosphorus-containing ligands in the synthesis of adiponitrile by butadiene method

Abstract

The invention discloses a method for inhibiting the degradation of a phosphorus-containing ligand in the synthesis of adiponitrile by a butadiene method. The method is to add an organic base in the isomerization reaction and the secondary hydrocyanation reaction, and the organic base is triethylamine , diethylamine, dimethylamine, hexamethylenediamine, pyridine, aniline, ethylenediamine, N,N-dimethylaniline or N,N-diethylaniline. In the present invention, by adding an organic base in the isomerization reaction and the secondary hydrocyanation reaction, the degradation of the phosphorus-containing ligand in the isomerization reaction and the secondary hydrocyanation reaction is effectively inhibited, and the degradation rate of the phosphorus-containing ligand is controlled. Within 5%, therefore reducing the supplementary amount of phosphorus-containing ligand, can improve the separation and recovery rate of zero-valent nickel catalyst and phosphorus-containing ligand simultaneously, have reduced the raw material cost of butadiene method synthetic adiponitrile, and the present invention The method has no effect on the conversion rate and selectivity of the isomerization reaction and the secondary hydrocyanation reaction.

Description

technical field [0001] The invention relates to the technical field of adiponitrile production, and relates to a method for inhibiting the degradation of phosphorus-containing ligands in the synthesis of adiponitrile by a butadiene method. Background technique [0002] The molecular formula of adiponitrile is CN (CH 2 ) 4 CN, abbreviated as ADN in English, is one of the most important raw materials for the production of new material nylon 66. Its properties are colorless oily liquid, slightly sweet, toxic and corrosive, and its density is 962g / cm 2 , melting point 1°C, boiling point 295°C (1atm). In addition, it also has broad applications in electronics, light industry and other organic synthesis fields. [0003] There are many synthetic methods of adiponitrile, and the current production routes of adiponitrile mainly include acrylonitrile electrolytic dimerization method and butadiene method. The synthesis of adiponitrile by the butadiene method mainly includes three s...

AI Technical Summary

Problems solved by technology

[0007] However, after the isomerization and secondary hydrocyanation reactions are completed, after the product is separated, the zero-valent nickel catalyst and the phosphorus-containing ligand are separated and recovered for recycling, the phosphorus-containing ligand in the system is degraded, and the degradation rate is between 10% and 10%. 20%, a certain amount of phosphorus-containing ligands needs to be supplemented at this time, and the separation recovery rate of zero-valent nickel catalyst and phosphorus-containing ligands needs to be reduced simultaneously, which increases the cost of raw materials for the synthesis of adiponitrile by the butadiene method

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