Financial feasibility and optimization of anaerobic digestion systems for sustainable waste management: A comprehensive global analysis

Effective management of organic waste plays a vital role in addressing environmental challenges and advancing sustainable development goals. This review article provides a comprehensive financial assessment of anaerobic digestion (AD) systems for treating the organic fraction of municipal solid waste (OFMSW). Previous studies on AD systems have largely been confined to local case studies with findings that cannot be generalized beyond their specific regions, and they have often overlooked the combined influence of technical, economic, and political factors on financial performance. The study begins by identifying the gaps and limitations in existing financial models for AD systems. It then develops an enhanced financial framework and uses scenario-based analyses to assess the financial feasibility of AD technologies. The model outputs indicate that the financial feasibility of AD systems is heavily influenced by national energy policies and environmental regulations. It is revealed that insufficient government support for energy tariffs—particularly in countries experiencing economic instability—serves as a major barrier to the cost-effectiveness of AD systems. In contrast, in economically stable regions, the financial sustainability of these systems is primarily challenged by stringent environmental regulations specifically related to digestate disposal. To overcome these challenges and further strengthen the financial performance of AD systems, future research should prioritize AI-driven optimization to enhance operational efficiency, reduce costs, increase energy output, and ultimately improve financial sustainability. By addressing existing barriers and proposing actionable recommendations, this review aims to foster the adoption of AD technologies as a cornerstone of sustainable waste management practices.