BTX production from rice husk by fast catalytic pyrolysis over a Ga-modified ZSM-5/SBA-15 catalyst†
Abstract
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, Brønsted–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.