The Used Cooking Oil-to-biodiesel chain in Europe assessment of best practices and environmental performance

Inappropriate disposal of Used Cooking Oils (UCOs) can generate major problems, such as the operational problems occurring in wastewater treatment plants when discharged into sewerage systems. In this paper the best methods to process the UCO-to-biodiesel chain are reviewed putting emphasis on the most critical technical and practical guidelines including best practices, quality characteristics of the collected UCO, potential implications, environmental performance and risks, and at the same time highlighting the strong and weak points of each analyzed route. The most common transesterification processes (homogeneous-catalyzed, heterogeneous-catalyzed, enzymatic, supercritical methanol, non-catalyzed) are evaluated according to environmental, technical, health and safety, market and EU policy criteria.