Integrated valorization of marine residue Posidonia Oceanica balls for the production of value added chemicals

Posidonia Oceanica balls (POb) are fibrous residues that are difficult to degrade and tend to accumulate in an uncontrolled manner on Mediterranean beaches, thus causing various environmental problems. Most of this marine residue is conferred in landfills and disposed into incinerators. Therefore, greener alternative treatments aiming at their valorisation simultaneously overcoming the environmental problems related to their accumulation would be very urgent. In this work, the cellulose fraction of this waste has been exploited for the synthesis of a highly interesting product, such as n-butyl levulinate (BL), one of the most promising bio-fuel blending additives for Diesel engines. The optimal alcoholysis conditions have been found by properly tuning the temperature, the biomass loading and the sulfuric acid loading. The highest BL yield of 42 mol% was achieved with a biomass loading of 5 wt% at 190 °C after 30 min. Also, the alkaline pre-treatment of POb has been preliminarily investigated, aiming at the removal of the lignin fraction, responsible for the recalcitrance of the cellulose conversion. In conclusion, for the first time, an integrated valorization of POb has been proposed giving mainly bio-fuels, as BL, and lignin.