Insight into staged gasification of biomass waste: Essential fundamentals and applications.

This article delves into the principle, essence, definitions, classifications, fundamentals, and industrial applications of staged gasification for biomass, offering an insightful exploration into its multifaceted dimensions. By segmenting the gasification process based on its intricate reaction network into distinct sub-processes implemented in separate reactors or reaction zones, staged gasification facilitates nuanced reaction control and sub-process intensification. It aims to optimize the gasification process by minimizing inhibitory effects and maximizing promotional interactions among chemical reactions, intermediates, or targeted products. This approach has been extensively tested, yielding significant technical benefits such as in-situ tar component conversion and efficiency enhancements. A clear categorization of the diverse staged gasification processes documented in literature is presented, distinguishing them based on the nature of interactions among separated stages, namely, chemical interaction, thermal interaction, and sequential staging. Definitions are provided for key concepts such as decoupling gasification, dual-bed or twin-bed gasification, and gasification with in-situ tar removal. Core fundamentals discussed include the reaction characteristics and kinetics of sub-processes, in-situ conversion of heteroatomic components, reactor configuration, and reaction regulation strategies. The article also presents an analysis of several industrial applications to elucidate the technical characteristics of staged gasification. Concluding with a discussion on prospective research concerns, this review underscores the evolving landscape of staged gasification technology and its pivotal role in advancing biomass conversion efficiencies.