Abstract
Fast pyrolysis of woody biomass was carried out without and with zeolite catalyst, and the correlation between the distribution of products and the character of catalysts was investigated. Eucalyptus was used as a model of woody biomass. In the case of noncatalyst pyrolysis, the main products were oxygenated compounds such as phenols and aldehydes. Zeolite catalysts chiefly favored the formation of aromatic hydrocarbons, both with and without O-atoms. H-ZSM-5 and H-beta zeolites were especially efficient for the formation of nonoxygenated aromatic compounds. However, high Si/Al2 ratio in H-ZSM-5 depressed the formation of nonoxygenated aromatics, while high Si/Al2 ratio in H-beta maintained the high yield of nonoxygenated aromatics. On the other hand, H-mordenite, USY, SAPO-34, 4A, 13X, and Ti-silicate showed a moderate catalytic activity for the formation of oxygenated as well as nonoxygenated aromatic compounds because of the moderate catalytic properties. Strong solid acidity (H-ZSM-5, H-beta, H-mordenite) favors the deoxygenation reaction. Large micropore diameter and three-dimensional microstructure (H-beta, USY) have advantages, because the intermediates can contact the active sites inside the micropore.
