A comprehensive review of recent advances in biomass pyrolysis…

Biomass pyrolysis is a promising thermochemical conversion pathway for producing renewable fuels, value-added chemicals, and carbon-based materials from sustainable feedstocks. However, the complex and highly sensitive nature of pyrolysis reactions, governed by biomass composition, operating conditions, and reactor design, continues to challenge predictive control and large-scale deployment. This review provides a comprehensive and critical synthesis of recent advances in biomass pyrolysis, with particular emphasis on feedstock characteristics; the thermal decomposition mechanisms of cellulose, hemicellulose, and lignin; and the influence of key operational parameters, such as temperature, heating rate, residence time, and particle size, on product distribution. Special attention is given to reaction intermediates and pathways identified through advanced analytical techniques, including Py-GC/MS, TG-FTIR, two-dimensional photoionization mass spectrometry, and complementary molecular-level simulations such as density functional theory and reactive molecular dynamics. By systematically integrating experimental observations with mechanistic insights, this review highlights current limitations, including the lack of unified kinetic models, weak coupling between experiments and simulations, and insufficient investigation of high-temperature pyrolysis regimes above 800 °C. Emerging opportunities for data-driven and machine-learning-assisted kinetic modeling are also discussed as a pathway to address biomass heterogeneity and complex reaction networks. The findings presented herein aim to support the development of predictive pyrolysis models, optimized reactor design, and the sustainable valorization of biomass within future bioenergy and biorefinery systems.