Sustainable Exploitation of Posidonia oceanica Balls through an Integrated Biorefinery Approach

Abstract

This work proposes the integrated exploitation of fibrous balls of seagrass Posidonia oceanica (PO), which annually accumulate along the sandy Mediterranean beaches, causing significant management and economic problems. Preliminarily, the organic extractives of PO balls were removed by ethanol, and their characterization highlighted the presence of biologically active molecules. The successive alkaline pretreatment allowed the fractionation of the biomass, leading to a solid enriched in polysaccharides and a "black liquor" containing the extracted lignin. The butanolysis of the solid enriched in polysaccharides provided a yield of up to 52.3 mol % of butyl levulinate, a strategic intermediate, and valuable bioblendstock for diesel. Finally, pure acid-insoluble lignin and acid-soluble lignin fractions were recovered from the "black liquor". These were deeply characterized and proposed as UV-blocker and antioxidant agents.