Multi-level synergistic fractionation technology toward lignocellulosic biomass refining

• Multi-level synergistic fractionation enhances biomass conversion efficiency. • Examination of bond dissociation enthalpies aid in biomass refining design. • Biomass refining contributes to sustainable process and economic viability. • Synergistic fractionation facilitates the disruption of lignin-carbohydrate linkage. • The fractionation mechanisms are offered at the molecular level. Lignocellulosic biomass represents a pivotal renewable resource for achieving sustainable bioeconomy. However, its recalcitrant structure, governed by hierarchical interactions among cellulose, hemicellulose, and lignin, poses significant challenges for efficient conversion. Consequently, fractionation processes are essential for the effective conversion of lignocellulosic biomass. This review systematically explores the multi-level synergistic application of steam explosion and alkaline hydrogen peroxide pretreatment to address these challenges. By analyzing bond dissociation enthalpies, this study elucidates the complementary roles of steam explosion and alkaline hydrogen peroxide pretreatment in selectively disrupting lignin-carbohydrate linkages and further facilitating biomass high-value utilization. Furthermore, integrated strategies to optimize multi-level fractionation were proposed, emphasizing the need for energy-efficient, scalable, and environmentally benign processes. Rational synergistic fractionation technology shows great advantages over single pretreatment in multi-level disassembling of lignocellulose. This review offers a comprehensive perspective on effective pretreatment strategies to enhance biomass conversion efficiency.