A Comparative Review of Waste-to-Energy Technologies for Municipal Solid Waste Management

Abstract

Waste-to-energy (WtE) technologies are an important component of sustainable waste management systems and provide a practical solution to the increasing challenges of municipal solid waste generation and increasing energy demand. WtE technologies convert wastes to useful forms of energy, which help to reduce the volume of wastes, to mitigate greenhouse gases, and to recover resources. This paper presents a review and comparative assessment of five major WtE technologies: incineration, anaerobic digestion, landfill gas-to-energy, gasification, and plasma gasification, evaluated in terms of technical performance, environmental impact, economic viability, social acceptance, and technology maturity. The review shows that Incineration reduces waste volume by up to 90% and achieves electrical efficiencies of 20–30% (rising to 80–90% under combined heat and power) but generates ash residues requiring specialized disposal. Also, anaerobic digestion converts organic waste into biogas containing 50–70% methane, with electrical efficiencies of 35–40% (55–65% under CHP configurations) and having the lowest air emissions among those technologies reviewed. Similarly, landfill gas-to-energy captures gas that is roughly 40–60% methane and 30–50% CO₂, generated over 15–25 years, providing a low-cost route to recovering energy from waste already in place. Furthermore, Gasification converts waste into syngas with electrical efficiencies of 30–40% (60–80% as syngas energy) at 700–1,500 °C, offering greater feedstock flexibility than incineration. Plasma gasification operates above 3,000 °C, achieves waste volume reductions of up to 95%, and delivers the highest syngas energy efficiency reviewed (65–75%), though at the highest capital cost of the five technologies. The results show that although conventional technologies such as incineration and anaerobic digestion are still the most widely used due to their well-established and reliable nature, advanced options such as plasma gasification show a better environmental performance and feedstock versatility at higher costs. This paper provides useful knowledge to help inform decisions on appropriate WtE technologies to be selected for sustainable waste management, especially in rapidly urbanising regions.