Abstract
Olive leaves is derived from the olive oil production with limited practical applications. This raw material can be used to obtain added-value products through its processing applying the biorefinery concept. Therefore, The aim of this work is to evaluate from a techno-economic and environmental perspective the production of antioxidants, lignin and ethanol using olive leaves as raw material through the use of experimental data and process simulation. For this, a biorefinery scheme composed by an acid extraction stage, organosolv pretreatment and simultaneous saccharification and fermentation process was simulated. This process was performed using experimental data obtained from the main conversion blocks of the proposed scheme assuming a linear scaling. Moreover, the separation and purification of the products were performed using conceptual process design tools. Then, the techno-economic assessment was carried out considering economic indicators of the Spain context for an operating facility with a 10 y life-time. Finally, the environmental evaluation was based in the specific solid, liquid and gaseous emissions calculation. The results showed that 100 g of feedstock can produce 38.24 g of antioxidant extract (phenolic compounds>10 %), 11.82 g of lignin and 3.65 mL of bioethanol. In addition, the techno-economic assessment showed that the proposed biorefinery is profitable when 30,000 t/y are processed with a total project cost of 49.1 M USD, an internal rate of return of 15.22 % and a payout period of 7.27 y. As conclusion, the application of the biorefinery concept to upgrade olive leaves in added-value products is feasible from a techno-economic point of view and the implementation of small scale biorefineries in Jaén (Andalusia, Spain).
