The Study On Preparation Of Meta-Diisopropylbenzene By Shape-selective Catalytic Cracking

Meta-diisopropylbenzene (m-DIPB) is an important raw material for chemical industry, and the market demand is increasing with the economic development. Because DIPB's three isomers are very close to the boiling point (the atmosphere, m-DIPB 203.18℃, o-DIPB 203.75℃,p-DIPB 210.37℃), and conventional distillation method purification m-DIPB out is difficult. ZSM-5 is one kind material which has the molecular sieve shape-selecting performance, the passing size can make the p-DIPB into them, and the inner surface of acid center takes place cracking reaction. M-DIPB and o-DIPB do not happen to cracking and only stay in molecular sieve surface.This paper firstly studies the reaction temperature, different process condition and modified to influence on the performance of the catalyst. Experiments show that 380℃is the best temperature of catalytic cracking reaction; adding suitable amount of benzene to the raw materials, which can improve the stability of the catalyst, but do not improve the shape-selective of the catalyst; Hydrothermal treatment can improve the stability of the catalyst and the shape-selective cracking.The experiment investigated the cracking reaction with different raw materials, The results show that the material with isomerization can greatly reduce the o-DIPB, also the content of the final product a falls significantly,Experiments contrast the different time and different temperature of hydrothermal treatment, and make sure the optimum hydrothermal treatment conditions. The study of the catalyst stability:80 h reaction results shows that o-DIPB content below 1%, a below 2%.