Bifunctional Ni‐ZSM‐5 Catalysts for the Pyrolysis and Hydropyrolysis of Biomass

Abstract In this work, we explore pyrolysis options, namely, high pressure, H 2 , and metal‐loaded ZSM‐5 catalysts, to improve the limited deoxygenation capacity and reduce the excessive production of solids in biomass catalytic fast pyrolysis (CFP). Specifically, we explore the product selectivity of Miscanthus x giganteus CFP in inert or H 2 ‐rich environments, pressures up to 450 psig, and over ZSM‐5 and Ni‐ZSM‐5. We show that higher pressures promote decarboxylation reactions, reduce the yields to liquids, and enhance the formation of solid products. Ni‐ZSM‐5 promotes decarboxylation, dehydration, and methanation reactions. The cofeeding of H 2 at high pressures increases the selectivity to monoaromatic hydrocarbons with a parallel enhancement of the yield to saturated products. Solid products are reduced drastically in H 2 ‐rich, high‐pressure experiments, and the CH 4 selectivity increases. Based on these experimental findings, we present a reaction scheme that describes the impact of pressure, H 2 , and Ni on the product selectivity of biomass CFP.