Application of hierarchical MFI zeolite for the catalytic pyrolysis of Japanese larch.

The catalytic pyrolysis of Japanese larch was carried out over a hierarchical MFI zeolite (Meso MFI C16). The zeolite was synthesized using an amphiphilic organosilane as a mesopore-directing agent, and its catalytic activity was compared with that of the conventional HZSM-5 and the mesoporous material from HZSM-5 (MMZ(ZSM-5)). The effect of the hierarchical MFI zeolite on the product distribution and chemical composition of the bio-oil was also examined. The hierarchical MFI zeolite exhibited the highest activity in deoxygenation and aromatization during the catalytic pyrolysis of Japanese larch. In particular, it showed high selectivity for valuable aromatics, such as benzene, toluene, and xylenes (BTX), even though it decreased the organic fraction of bio-oil. Its higher mesoporosity resulted, however, in an increase in the coke amount and in undesirable products, such as polycyclic aromatic hydrocarbons (PAHs).