Catalytic pyrolysis of willow wood with Me/ZSM-5 (Me = Mg, K, Fe, Ga, Ni) to produce aromatics and olefins

Abstract

Biomass catalytic fast pyrolysis is one of the most promising technologies for the production of renewable aromatics and olefins directly from solid biomass. In this study, catalytic pyrolysis experiments were carried out on biomass in a fluidized bed reactor using typical metal-loaded (Mg, K, Fe, Ga, and Ni) ZSM-5 zeolites as catalysts. The effects of catalysts on the product distribution and bio-oil components were investigated to determine the cheapest and most efficient metal-loaded catalyst. The results showed that bio-oil yields with metal-loaded catalysts (40 to 43.4 wt.%) were a little lower than that of pure ZSM-5 (46.4 wt.%). Metal-loaded catalysts produced more CO2 and CO than did pure ZSM-5. Fe/ZSM-5 produced the highest yield of CO2 (13.8 wt.%), as well as the highest yield of olefins (2.7 wt.%). Fe/ZSM-5 showed the same catalytic characteristics as Ga/ZSM-5 (aromatic hydrocarbon proportion in bio-oils of more than 80%), but it is much cheaper than Ga/ZSM-5.