Biorefining of olive tree (Olea europea) pruning

• Olive tree pruning was successfully proposed as raw material for biorefinery processes.
• Organosolv process was proved to enhance bioethanol production.
• Organosolv lignin was revalorized into biochemicals with current potential market.

In this work, olive tree pruning has been fractionated into its components to produce ethanol (biofuel) from the cellulose fraction and platform chemicals (biochemicals) from lignin fraction. Organosolv pretreatment has been proved to be an effective process that fractionate and produce intermediates – cellulose and lignin- that can be later transformed. Ethanol was successfully produced from cellulose enriched solid fraction with high yields, 71.9 g L−1 of glucose and 17.1 g of ethanol per 100 g of olive tree pruning. Organosolv pretreatment has been proved to enhance enzymes accessibility to the substrate and so, increased hydrolysis yields. Lignin was depolymerized into interesting compounds such as catechol and 4-methylcatechol. The chemicals obtained from lignin presented promising industrial applications. Repolymerization phenomenon was found to decrease the yields of the proposed lignin revalorization process.