Application of a kind of alkyl quaternary phosphonium salt ionic liquid in the synthesis of adiponitrile from adipic acid

Abstract

The invention provides an application of an alkyl quaternary phosphonium salt ionic liquid in the synthesis of adiponitrile from adipic acid. The alkyl quaternary phosphonium salt ionic liquid passes through the alkylation reaction of the alkyl quaternary phosphonium salt, and the corresponding imidazole and The phosphoric acid ester is prepared by one-step method. At a certain temperature, the ionic liquid catalyst, adipic acid and adiponitrile are added to the reaction kettle, and excess ammonia gas is introduced, and the reaction is performed for a certain period of time to obtain the product adiponitrile. The method for synthesizing the ionic liquid is simple and the operation process is convenient. The prepared ionic liquid is not volatile, difficult to oxidize, and easy to recycle; the ionic liquid has high polarity and strong complexation ability; anion and cation can be freely combined, and the structure is easy to control; it is non-flammable and explosive, and has high thermal stability .

Description

technical field [0001] The invention belongs to the technical field of adiponitrile synthesis, and in particular relates to the application of a plasma-modified alkyl quaternary phosphonium salt ionic liquid in the synthesis of adiponitrile from adipic acid and ammonia. Background technique [0002] As an important chemical raw material, adiponitrile can react with hydrogen to form hexamethylenediamine, and hexamethylenediamine and adipic acid react under strict material ratio to form nylon 66 salt. Therefore, adiponitrile, as an important intermediate in the synthesis of nylon 66, is the most important and most valuable industrial use of adiponitrile. [0003] At present, the methods for synthesizing adiponitrile mainly include electrolytic dimerization of acrylonitrile (AN), butadiene (BD) and catalytic amination of adipic acid (ADA). Among them, the adipic acid ammonification method is the first industrialized method for the synthesis of adiponitrile. At present, the met...

AI Technical Summary

Problems solved by technology

However, this type of catalyst faces a series of problems: firstly, a large amount of phosphoric acid and phosphoric acid ester will cause certain corrosion to the reactor and affect normal production; secondly, this type of liquid catalyst is easily soluble in the reaction system, causing catalyst loss and increasing Production cost; finally, phosphoric acid, etc. will generate polymers in the reaction, affecting heat transfer

It is reported in the literature that ethylmethylimidazolium dihydrogen phosphate ionic liquid is used in the nitrilation of adipic acid to prepare adiponitrile. The author conducts discontinuous reaction through the reactor and feeds ammonia gas in batches at the same time. The operation steps are complicated and are not conducive to scale-up. Production, difficult to achieve industrialization (CN 201710540292.1)