BTX production from rice husk by fast catalytic pyrolysis over a Ga-modified ZSM-5/SBA-15 catalyst

Hierarchical zeolites are promising for the development of biomass catalytic fast pyrolysis; composite molecular sieves with efficient catalytic activity are needed to expand their practical applications. Micro-mesoporous ZSM-5/SBA-15 composite molecular sieves doped with different amounts of Ga element were successfully synthesized via an isometric impregnation method. The physical structures of the prepared materials were characterized by energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and pyrolysis infrared spectroscopy. Based on these analyses, Ga was distributed uniformly on the surface of the composite molecular sieve catalyst. As Ga loading increased, Bronsted-Lewis (B + L) acids increased. Pyrolysis of rice hull was performed using a multi-function catalyst evaluation device and catalytic performance and anti-coking performance were evaluated. Ga-modified ZSM-5/SBA-15 showed better benzene, toluene, and xylene (BTX) catalytic selectivity and anti-coking properties compared to those of undoped catalysts. Additionally, the 2%Ga-ZSM-5/SBA-15 zeolite composite showed the best BTX catalytic selectivity, with a BTX yield of 25.52%, clearly demonstrating its potential for application in BTX production and practical uses in petrochemical industries.

Automated summary

The hierarchical zeolites doped with different amounts of Ga element were successfully synthesized via an isometric impregnation method. The addition of Ga increased Brønsted-Lewis (B + L) acids, leading to improved benzene, toluene, and xylene (BTX) selectivity and anti-coking properties. The 2%Ga-ZSM-5/SBA-15 zeolite composite showed the best BTX catalytic selectivity, with a BTX yield of 25.52%, demonstrating its potential for practical applications in BTX production and petrochemical industries.