Microdynamics of biomass steam gasification: A review

Biomass as a zero-carbon fuel plays a pivotal role in global sustainable energy development. Among diverse biomass-based energy utilization methods, biomass steam gasification emerges as a crucial pathway for low-carbon utilization and green hydrogen production. Microdynamics unravel the chemical mechanisms of biomass steam gasification at the molecular level, offering profound insights into material behavior, energy transfer, and chemical reactions. Consequently, optimizing the gasification process, improving gasification efficiency, and minimizing energy losses are attainable goals, thereby fostering the development of detailed kinetic mechanisms and theoretical guidance for reactor design and performance optimization. This review is the first comprehensive overview of microdynamics in biomass steam gasification, meticulously examining and analyzing the literature. The primary focus lies on char steam gasification reactivity, carbonaceous structure conversion, the migration and transformation processes of various elements, and the catalytic mechanisms of alkali and alkaline earth metals in ash. Emphasis is placed on the imperative need to develop in-situ monitoring experimental methods and refine biomass char molecular structure models. Furthermore, the review proposes research directions for advancing detailed kinetic mechanisms in biomass steam gasification. It provides a systematic and foundational basis for the cleaner and more efficient utilization of biomass energy from a microdynamics perspective.