Waste to Energy Conversion: Technologies, Challenges and Sustainable Prospects

Waste-to-Energy (WtE) conversion has emerged as a sustainable strategy for addressing the dual challenges of increasing waste generation and growing energy demand. This study presents a comprehensive review of thermochemical, biochemical, and hybrid WtE technologies, including incineration, pyrolysis, gasification, anaerobic digestion, and refuse-derived fuel systems. Comparative analysis indicates that gasification exhibits electrical efficiencies of 25–40%, while anaerobic digestion provides methane yields of 100–250 m³ per ton of organic waste with comparatively lower greenhouse gas emissions. Incineration remains the most commercially mature technology, achieving waste volume reduction of up to 90%, although concerns regarding air pollutant emissions persist. The review highlights recent advancements in catalytic conversion, AI-based process optimization, and integrated waste management systems. Environmental and socio-economic analyses demonstrate that WtE can significantly reduce landfill dependency, lower methane emissions by 40–70%, and contribute to circular economy objectives. The study concludes that the integration of advanced technologies, supportive policies, and public participation is essential for maximizing the sustainability and scalability of WtE systems, particularly in developing countries such as India.