Lignocellulosic municipal waste valorization for energy recovery and circular bioeconomy

This review examines the valorization potential of the lignocellulosic fraction of municipal solid waste (MSW) as a renewable feedstock for sustainable energy and material production. Comprising paper, cardboard, yard trimmings, and food residues, lignocellulosic MSW constitutes a major biodegradable component of urban waste streams with high volatile content and favorable energy density. The review synthesizes recent advances in biochemical (anaerobic digestion and fermentation) and thermochemical (pyrolysis and gasification) conversion technologies, focusing on their underlying mechanisms, process efficiencies, product yields, and environmental implications. Through a critical mapping of technological progress, system integration strategies, and sustainability assessments, this review highlights pathways toward scalable and circular waste valorization. Comparative analysis indicates that biochemical routes are better suited for wet and heterogeneous feedstocks, whereas thermochemical pathways offer higher conversion efficiencies and greater flexibility for energy recovery. Life-cycle assessments (LCAs) further demonstrate that integrating these technologies with effective sorting, pretreatment, and carbon valorization strategies can substantially reduce greenhouse gas (GHG) emissions and landfill dependence. The review also identifies persistent challenges related to feedstock variability, contamination, and process integration, while highlighting opportunities for hybrid biochemical–thermochemical systems and biochar-based carbon sequestration. Overall, this review advances a sustainability framework in which lignocellulosic MSW is re-envisioned as a cornerstone of circular bioeconomy development, supporting decarbonization and resource efficiency in urban systems.