Circular Economy Model for Valorization of By-Products and Effluents from a Portuguese Olive Oil Production Unit

All the by-products from a two-phase olive oil mill, including olive pomace, stones, leaves, and raw vegetation water were collected and characterized. The two-phase olive pomace was further fractionated by filtration and dried to determine recovered liquid phase and dry weight. Using the obtained results and literature data were proposed two scenarios for the valorization of olive mill by-products following an approach focused on the promotion of circular economy and mitigation of GHG emissions. Scenario I involves drying the two-phase olive pomace while scenario II proposes filtration to remove excess water followed by drying. This last option (scenario II) would help to reduce the costs and carbon footprint of transporting wet olive pomace to units that extract residual oil and allows the use of smaller drying units. Decentralized filtration and drying of two-phase pomace is therefore an alternative to improve the quality and added value of the olive mill by-products thus supporting small producers. On the other hand, this option requires the implementation of sustainable methods for liquid effluents distillation and water recovery preferably using renewable energy sources.