Bio-oil production from sequential two-step microwave-assisted catalytic fast pyrolysis of water hyacinth using Ce-doped Γ-Al₂O₃/ZrO₂ composite mesoporous catalyst

A sequential two-step microwave-assisted catalytic fast pyrolysis (MACFP) of water hyacinth for hydrocarbon-rich bio-oil production is studied. This newly developed technique is characterized by microwave-assisted fast pyrolysis followed by catalytic upgrading using an additional catalyst packed bed, and it thus achieves the independent control of pyrolysis and catalytic upgrading. On the other hand, in order to minimize coke formation and promote hydrocarbon production in sequential two-step MACFP of water hyacinth, Ce-doped γ-Al₂O₃/ZrO₂ composite mesoporous catalyst (CAZ) is synthesized and used in this study. The effects of catalyst type, pyrolysis temperature, catalytic upgrading temperature and catalyst reusability on product distribution and chemical compositions in bio-oil are investigated. The results demonstrate that water hyacinth is a good biomass candidate for fuel demand, and CAZ can facilitate the hydrocarbon fuel production in bio-oil and exhibits an excellent catalyst reusability. Meanwhile, it is found that the optimal temperatures for water hyacinth pyrolysis and pyrolytic vapor upgrading are 650 °C and 450 °C, respectively.