Research Progress in the Application of Advanced Oxidation Pretreatment for Biomass Energy Production

Abstract

Lignocellulosic biomass is an abundant renewable energy resource whose total energy content far exceeds current global demand. Its polysaccharides, cellulose, and hemicelluloses are primary targets for valorization; however, the recalcitrant structure of plant cell walls necessitates effective pretreatment. Among physical, physicochemical, chemical, and biological methods, advanced oxidation processes (AOPs) have emerged as an efficient and environmentally compatible chemical strategy. This review systematically evaluates nine major AOPs for lignocellulosic biomass pretreatment: Fenton and Fenton-like processes, alkaline H₂O₂, peracetic acid, persulfate, ozone, photocatalysis, electrochemical oxidation, wet air oxidation, and cavitation-assisted methods. For each, reaction mechanisms, advantages and limitations, recent advances, economic considerations, and scale-up challenges are discussed. Persulfate-based systems, wet air oxidation, and hybrid strategies (e.g., photo-Fenton, alkaline H₂O₂–cavitation, electrochemical–ozone–H₂O₂) are identified as particularly promising. Future research should prioritize novel catalyst development, reactor optimization, multi-mechanism integration, and rigorous techno-economic and life-cycle assessments. Coupling AOPs with renewable energy sources will be critical to improving energy efficiency and enabling cost-effective large-scale application.