Conclusions

In conclusion, this work presented a novel route for the synthesis of ZSM-5 zeolites by using RPB for enhancing micromixing of high viscosity reaction system in the premix process. The as-prepared ZSM-5 zeolites by RPB premix exhibited hierarchical structure, smaller average particle size, more uniform particle size distributions, larger specific surface areas, more Brønsted and Lewis acid sites, and higher catalytic stability compared with those prepared by STR premix. Moreover, enhancing micromixing by RPB could facilitate the formation of Al sites and shorten the crystallization time. Also, the mechanisms of the nucleation/crystal growth process of zeolites under different micromixing intensity were studied. While adopting the prepared zeolites for catalyzing C4-olefin cracking reaction, zeolites prepared via RPB premix exhibited the remarkably higher conversion of C4-olefin and yield of propylene. Generally, the RPB premix synthetic routes speeded up the crystallization rate of zeolites and improved zeolites’ catalytic performance with the advantages of convenient processing, cost-effectiveness, easy industrial scale-up.