Technical and Economic Analysis of Used Cooking Oils in Bioenergy System: Comparative Case Studies

Used cooking oil (UCO) can be considered either a waste product with negative effects on the environment or a resource if contributing to energy production. This thesis investigates the technical feasibility of integrating UCO into two bioenergy systems: anaerobic digestion (AD) for biogas production and transesterification process for biodiesel production. A comparative analysis of the case studies of Emilia Romagna and Missouri was conducted to develop alternative scenarios for the reuse and valorization of UCO and to identify potential policy interventions to stimulate its integration in bioenergy systems. The work demonstrated the technical and economic feasibility of the substitution of energy crops with UCO with particular emphasis on the potential implications on land use. Moreover, results suggest that the introduction of UCO in the feeding mix could lead to significant land saving. The use of UCO would allow to maintain a stable production of energy along the year, to mitigate the environmental impact, and to ensure economic benefits for farmers. Although the substitution of ECs with UCO is technically feasible and economically viable, in both Countries a major constraint is represented by the current legislative framework that limits the collection and the utilization of UCO for anaerobic digestion. Policy interventions should be aimed at removing the barriers that currently limit UCO collection and reuse in bioenergy systems. They should focus also on the creation of public-private relationship aimed at facilitating UCO collection and disposal and on awareness rising to inform food chain stakeholders about the economic and environmental benefits of the integration of UCO in bioenergy systems. Finally, the comparative analysis pose a question on the definition and on the sustainability of the concept of short supply chain that should be addressed by taking into consideration logistical and geographical barriers, and the availability of local resources