Continuous Tubular Reaction Catalyzed Preparation Of N,N-dimethylaniline And Its Macroscopic Reaction Kinetics

Aniline N-alkylation reaction is an important commercial chemical reaction.The N-alkylated products of N-methylaniline,N,N-dimethylaniline can be used for paper making,textile dyes,drugs,spices and explosions goods and many other industrial products of important production.In this paper,the properties and synthesis methods of N,N-DMA were summarized,and the application status and research status of N,N-DMA were summarized.On the basis of analyzing the existing synthetic routes ofN,N-DMA,the method of replacing the traditional reactor with tubular catalytic reactor was put forward.Dealumination by various acids were performed to adjust the whole acidity of HP.It was found that mixture of hydrocloric and oxalic acids was superior in improving the selectivity of aniline N,N-dimethylation Upon mixed-acid treatment,the surface area and pore volume of catalyst were increased,and the amount of strong Bronsted acid sites remained.These were responsible for the high yield ofN,N-DMA.Due to the selective removal of the extra-framework Al species,a decrease in the number of Lewis acidic sites were advantageous to suppress the hydride transfer and subsequent side reactions that form coke,leading to the increase in selectivity of N,N-DMA.An appropriate process of N,N-dimethylaniline synthesis should be determined for the parameter optimization experiments,which were operated on the tubular reactor.And various effects on the reaction results were studied,such as catalyst,temperature,ratio of raw materials and liquid hourly space velocity(LHSV).In addition,the experimental results were optimized via the orthogonal experiment combing the single-factor-alternate method,providing the basic experimental data for the further research.Under the optimized conditions,the conversion of aniline and the selectivity of N,N-dimethylaniline were improved.According to the study of aniline N-methylation,a suitable process including side-stream distillation and extractive distillation was proposed to produce N,N-DMA from aniline N-methylation.various parameters of side-stream distillation and extractive distillation were optimized by Aspen Plus.Based on the optimal simulation results,side-stream distillation and extractive distillation experiments were carried out.Under optimized conditions,the N,N-dimethylaniline content and yield reached a better indicator.Further research on the macro kinetics model was carried out on the base of N,N-DMA synthesis mechanism using reaction kinetics equation of power function.According to the experimental data,the macro kinetics model was calculated,after which the applicability of the model was testified with statistical methods.Simultaneously,providing a theoretical basis for industrial amplification reaction.And the equation is as follows:(?)...