In this study, a pre-feasibility assessment and analysis of alternatives and options for a biomass energy plant in Lipari, supplied with the organic fraction of municipal solid waste (OFMSW) from the Aeolian Islands, were performed. The study includes preliminary sizing, cost estimation of the plant, and assessment of the costs and emissions associated with transport and processing. As this is a pre-feasibility, the focus was placed on the key challenges and opportunities of a small-scale biowaste plant. More detailed technological, economic and legal issues may be addressed in more detail in a follow-up study.
Based on the information provided by the local municipalities, the expectations are that the Lipari plant must be sized to handle ~2,500 tons/yr of OFMSW in the near term and up to ~3,300 tons/ yr in the future. The most suitable biowaste valorisation technology for the Aeolian islands was found to be dry feed, continuous flow, single-stage thermophilic anaerobic digestion (AD) combined with a gas engine with heat recovery (CHP) to produce power for the grid and heat to feed the plant. This is because AD configuration is the most established technology in the municipal waste processing industry, the least water and labour intensive, and the electricity output directly replaces diesel for power generation. In terms of economic feasibility, the central question is whether the techno-economics of a small-scale (3,300 ton/y) Lipari-based biowaste valorisation plant can compete with the superior economy of scale of a >30,000 tons/yr mainland plant. The turnkey point mainly lies in the transport costs of the waste from the archipelago to the mainland.