Synthesis of hierarchical ZSM-5 zeolite by high gravity technology

doi:10.16085/j.issn.1000-6613.2017.02.026

Abstract

Abstract: Hierarchical ZSM-5 zeolite was prepared in a novel impinging stream-rotating packed bed reactor(IS-RPB)by a toilless salt-aided seed-induced route. The effects of rotation speed,colloidal silica flow rate,natrium aluminate mixture flow rate and cycle time on the structure of mesopores were investigated. The high gravity technology was compared with traditional hydrothermal synthesis method. The as-prepared hierarchical ZSM-5 zeolite was characterized by XRD,SEM,the laser particle size analyzer and N₂ adsorption-desorption techniques. The experimental results indicated that the optimum operating condition was:the rotation speed of 1200r/min,colloidal silica flow rate of 30mL/min and natrium aluminate mixture flow rate of 20L/h. The remarkable micromixing property of the IS-RPB led to the formation of hierarchical ZSM-5 zeolite with narrow particle size distribution and regular morphology with obviously decreased crystallization time. This work provided a new method for the industrial production of hierarchical ZSM-5 zeolite.

Key words: high gravity, Socong Mobil^#5, moleclar sieves, impinging stream-rotating packed bed reactor

摘要： 尝试采用加盐晶种法，以撞击流-旋转填料床为反应器，制备出多级孔ZSM-5分子筛，考察了转速、硅胶流量、含晶种的铝源混合物流量和循环时间对产物的粒度分布及介孔结构的影响，并针对晶化时间、晶粒形貌、结构性能三方面与传统水热合成法进行对比。采用X射线衍射仪（XRD）、扫描电镜（SEM）以及N₂吸附脱附对产物的形貌及结构性能进行表征。研究结果表明，超重力技术制备多级孔ZSM-5分子筛的最佳工艺条件为：转速1200r/min，硅胶流量30mL/min，含晶种的铝源混合液流量20L/h；应用超重力技术相比于传统水热合成法制备出的多级孔ZSM-5分子筛拥有更多的介孔数量，形貌较好无杂相，粒度分布更均一，且所需晶化时间显著降低；微观混合效率对多级孔ZSM-5分子筛的形成有一定影响。本文为改善多级孔ZSM-5分子筛的工业化生产提供了一条新思路。

关键词: 超重力, ZSM-5, 分子筛, 撞击流-旋转填料床

CLC Number:

TQ031

CHENG Shangyuan, LIU Youzhi, QI Guisheng. Synthesis of hierarchical ZSM-5 zeolite by high gravity technology[J]. Chemical Industry and Engineering Progree, 2017, 36(02): 588-594.

成尚元, 刘有智, 祁贵生. 超重力技术制备多级孔ZSM-5分子筛[J]. 化工进展, 2017, 36(02): 588-594.

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