Highly crystalline binder-free ZSM-5 granules preparation

Abstract

A new environmental friendly technology was developed for the preparation of highly crystalline binder-free zeolite ZSM-5 granules. It comprises a preparation of amorphous aluminosilicate granules by using inexpensive industrial reactants like sodium water glass and sodium aluminate without the use of organic structure directing agents. Dried aluminosilicate gel was compacted in granules by using sodium water glass as a “pseudo-binder”. Zeolite ZSM-5 granules were prepared by hydrothermal crystallization at 180 °C after 24 h by using lifted set-up reactor in 0.01 M NaOH comprising 10 wt% of amorphous aluminosilicate granules. The influence of crystallization temperature and time, SiO2/Al2O3 molar ratio of reactants and relationship between the amount of amorphous aluminosilicate granules and NaOH medium during hydrothermal treatment on the crystallization process of granulated ZSM-5 product were monitored and characterized by X-ray diffraction, X-ray fluorescence, scanning electron microscope, and N2 physisorption technique. The presented procedure enabled more than doubled increase of the synthesis product yield, which positively impacts the economy and ecology of the production process.