3 results about "Hexamethyleneimines" patented technology

This invention discloses a method for preparing hexamethylenediamine, comprising the following steps: (1) under ammoniation reaction conditions, optionally in the presence of a solvent, subjecting hexanediol and ammonia to an ammoniation reaction to obtain an ammoniation reaction product; (2) separating and obtaining from the ammoniation reaction product a stream containing hexamethyleneimine and water, dehydrating the stream containing hexamethyleneimine and water to obtain a dehydrated stream containing hexamethyleneimine, and returning at least part of the dehydrated stream containing hexamethyleneimine as a circulating stream to the step (1), wherein a water content in the dehydrated stream containing hexamethyleneimine is less than 3 wt %, preferably less than 1.5 wt %. The invention can not only improve the yield of hexamethylenediamine but can also prolong the service life of the catalyst.

The application provides a MWW structure molecular sieve and a preparation method and application thereof. The preparation method comprises the following steps: mixing an aluminum source, water, an alkali source, a first template agent, a second template agent, a silicon source and seeds to form a gel, and crystallizing the gel to obtain the MWW structure molecular sieve; wherein the first template agent comprises cyclohexylamine, and the second template agent comprises at least one of diisopropylamine, di-n-butylamine, diisobutylamine, 1,4-diazabicyclo[2.2.2]octane, 1,6-hexanediamine and N,N,N,N-tetramethyl-1,6-hexanediamine. The application further provides the MWW structure molecular sieve prepared by the above preparation method and the application of the MWW structure molecular sieve. According to the application, the MWW structure molecular sieve can be directly synthesized without using hexamethyleneimine, piperidine and homopiperazine by the method of seed and two template agents assisting crystallization.

The application belongs to the technical field of catalyst preparation, and particularly relates to a CuOx / Ti-MWW composite catalyst and a preparation method and application thereof. The method comprises the following steps: mixing and stirring hexamethyleneimine, water, tetrabutyl titanate and silica sol, and irradiating a precursor solution by using an ultraviolet light assisted method; placing the precursor solution and porous alpha-Al2O3 particles coated with Ti-MWW molecular sieves in a reaction kettle to perform a hydrothermal synthesis crystallization reaction, then placing the particles in a fluoride solution for impregnation, washing, drying, calcining to obtain a monolithic multi-level hole Ti-MWW molecular sieve; finally, mixing the molecular sieve with a Cu(OH)2 suspension and placing the mixture in a reaction kettle, then placing the reaction kettle in an oven to perform a reaction, after the reaction, washing, drying and calcining, and the catalyst is obtained. The catalyst provided by the application not only improves the dispersion degree of CuOx, but also enhances the interaction between CuOx and the Ti-MWW carrier, thereby significantly improving the activity and stability of the catalyst.