Advances in Catalytic Pyrolysis of Lignin toward Aromatic Hydrocarbon Production

• • HZSM-5 zeolite catalysts, particularly metal-modified variants (e.g., Fe/ZSM-5), enhance monocyclic aromatic hydrocarbon yields from lignin pyrolysis; Fe content and temperature critically influence selectivity, with optimal performance reported at specific Fe loadings and temperatures (e.g., 2019 study). • • Two-stage fixed bed reactors combining in-situ natural zeolite and ex-situ HZSM-5 improve aromatic yields by sequential catalytic upgrading, as demonstrated in 2016 research. • • Torrefaction deoxygenation pretreatment of lignin prior to catalytic fast pyrolysis with metal-modified zeolites significantly boosts bio-aromatics production, as shown in 2020 studies. • • Transition-metal modified HZSM-5/MCM-41 core-shell catalysts enhance monocyclic aromatic hydrocarbon yields from enzymatic hydrolysis lignin, with performance dependent on metal type and core-shell structure (2023-2024 studies).