Abstract:
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.