From giant reed to levulinic acid and gamma-valerolactone: A high yield catalytic route to valeric biofuels

The acid hydrothermal conversion of a non-food dedicated feedstock – giant reed (Arundo donax L.) – to levulinic acid (LA) was investigated. LA is a versatile intermediate for the production of biofuels and bio-based chemicals. LA was subsequently hydrogenated to γ-valerolactone (GVL), a sustainable liquid and valuable fuel additive and a precursor for the new platform of “valeric biofuels”. The straight production of GVL directly from water slurries of giant reed was studied by adopting bifunctional (acid and hydrogenating) catalytic systems based on Ru/C and niobium oxide or niobium phosphate. Mild reaction conditions (only 0.5 MPa of hydrogen and 70 °C) are possible for the hydrogenation step. GVL yields up to 16.6 wt.% calculated from the starting weight of dry biomass were reached, with an almost complete and selective conversion of the intermediate LA.