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.