Experimental study on bio-oil from catalytic pyrolysis on Fe modified HZSM-5

The 2% Fe modified HZSM-5 zeolite catalysts were prepared by ion-exchange and characterized by laser particle size analyzer, specific surface area and pore size analyzer, and X-ray diffraction (XRD) to investigate the pore and surface properties. The catalytic pyrolysis of wood was carried out at 550 ℃ to get the maximum oil yield. After pyrolysis, the bio-oil was separated to the lighter (upper layer) and heavier component (bottom layer). The results indicate that with Fe modified HZSM-5 catalysts, the bio-oil yield increases significantly (maximum 7%) the same as that of the lighter one, while the heavier one is nearly constant. Ketones and furans in the lighter oil decreases, while acids and phenols increase significantly; in the heavier oil, ketones and furans decreased dramatically, phenols and naphthalenes increase significantly. The Fe modified HZSM-5 catalysts play an important role in pyrolysis of wood dusts, and have a critical influence on oil yield because the modified catalysts promote the shape-selective modifying of the initial pyrolysis steam and inhibit the secondary coking reaction of steam. The product tends to much lighter bio-oil component and lower oxygen content.