摘要
针对ZSM-5分子筛合成成本高、微孔结构易引起扩散限制的问题,文中以六亚甲基亚胺(HMI)为主模板剂,聚氧乙烯聚氧丙烯醚(F68)为介孔模板剂,采用蒸汽辅助晶化法合成多级孔ZSM-5分子筛(SFZ),探究NaOH添加量、晶化时间以及F68添加量对分子筛结晶度的影响。此外,采用X射线衍射(XRD)、扫描电镜(SEM)、N_(2)吸附-脱附及氨程序升温脱附(NH_(3)-TPD)等手段对催化剂的物理化学性能进行了表征,对低密度聚乙烯(LDPE)进行了催化裂解,并且评价了分子筛的催化性能。结果表明,SFZ-15(F68添加量为HMI质量的15%)获得了最高的液体产率(21.42%)和苯系物(BTEX,如苯、甲苯、乙苯、二甲苯)选择性(86.34%),同时表现出优异的抗积碳能力和催化稳定性。
ZSM-5 zeolites have problems of high synthesis cost and small pore caused diffusional limitations.Hexamethylenimine(HMI)and polyethylene-polypropylene glycol(F68)were used as the micropore and mesopore templates respectively to synthesize hierarchical ZSM-5 zeolite(SFZ)via a steam-assisted method.Effects of NaOH,F68 addition amounts,and crystallization time on the crystallinity of synthesized zeolite was investigated.The physicochemical properties of the zeolites were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),N_(2) adsorption-desorption,and ammonia temperature-programmed desorption(NH_(3)-TPD).The performance of the catalyst was evaluated by catalytic cracking of low density polyethylene(LDPE).The results show that SFZ-15%(F68/HMI mass ratio=15%)achieves the highest liquid yield(21.42%)and BTEX(benzene,toluene,ethylbenzene,xylene)selectivity(86.34%).Moreover,SFZ-15%exhibits excellent coke resistance and catalytic stability.
作者
葛虎城
顾宇飞
黄雪
刘菲菲
黄艳梅
李福威
李志霞
GE Hucheng;GU Yufei;HUANG Xue;LIU Feifei;HUANG Yanmei;LI Fuwei;LI Zhixia(School of Chemistry and Chemical Engineering,Guangxi University,Nanning 530004,China)
出处
《高校化学工程学报》
北大核心
2025年第1期95-104,共10页
Journal of Chemical Engineering of Chinese Universities
基金
国家自然科学基金(22078076)
广西自然科学基金(2020GXNSFAA159174)。
