Advances in Municipal Solid Waste Valorization and Energy Recovery: A Comprehensive Review of Thermochemical, Biochemical, and Integrated Biorefinery Approaches

Abstract

Municipal solid waste (MSW) management is emerging as one of the key global sustainability challenges. The increasing waste generation rate—driven by rapid urbanization, industrialization, and population growth—poses severe environmental, economic, and social pressures. Conventional landfilling and open dumping practices result in greenhouse-gas (GHG) emissions, groundwater contamination, and loss of valuable resources. Waste-to-energy (WtE) conversion provides a viable pathway for transforming waste into useful forms of energy and materials, aligning with circular-economy and net-zero objectives. This review synthesizes progress in thermochemical (incineration, gasification, and pyrolysis) and biochemical (anaerobic digestion and composting) technologies and highlights recent developments in integrated MSW bio refineries. Comparative analyses of energy efficiency, environmental performance, and techno-economic viability are presented. The study identifies research priorities such as hybrid reactor design, advanced catalysts, digital optimization, and policy instruments that promote sustainable resource recovery.