Using the ash of common water reeds as a silica source for producing high purity ZSM-5 zeolite microspheres

Utilizing of ash extracted from Iraqi common water reeds as an inexpensive effective silica source in the preparation of ZSM-5 zeolite was investigated for the first time in the present work. This study was conducted using a hydrothermal treatment at autogenous pressure. The molar content of silica (17.84-26.76), sodium oxide (1.71-2.4), water (76.92-304.6), organic template (0.55-2.73), organic solvent (23.46-140.76), and synthesis conditions (crystallization time (24-72 h) and temperature (130-180 degrees C)) were investigated to obtain high purity ZSM-5 zeolite microspheres. The zeolite samples were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Analysis by X-Ray (EDAX), N-2 adsorption/desorption isotherms, Thermogravimetric Analyzer (TGA), and Fourier transform infrared spectroscopy (FTIR). XRD pattern of all synthesized samples was compared to XRD pattern of the commercial ZSM-5 zeolite. This work allows using locally available solid waste resulted from a dry natural plant as an inexpensive silica source without using an external source of silica. Also, this is the first report of the direct synthesis of a high purity ZSM-5 zeolite microspheres from common water reeds ash containing highly reactive silica. A gel composition of 2Na(2)O: 26.76SiO(2): Al2O3: 2.73TPAOH: 23.46EtOH: 304.6H(2)O gave an outstanding final product of ZSM-5 zeolite microspheres at 180 degrees C and 27 h. This high crystallinity ZSM-5 zeolite porous microspheres possess Si/Al ratio of 17, a crystal size of 61.419 nm, BET surface area of 277.482 m(2)/g, a total pore volume of 0.1659 cm(3)/g, micropore volume of 0.1131 cm(3)/g, pore width of 5.28 nm, and hierarchical factor of 0.14.

Automated summary

This study investigated the use of ash extracted from Iraqi common water reeds as a cost-effective silica source for the preparation of ZSM-5 zeolite. By exploring different molar contents and synthesis conditions, high purity ZSM-5 zeolite microspheres were successfully synthesized. The method eliminated the need for an external silica source and achieved direct synthesis of high purity ZSM-5 zeolite microspheres.