A green approach for the valorization of Arundo donax L. and paper mill waste to produce the advanced biofuel n-butyl levulinate

Today, the continue depletion of fossil sources represents one of the main problems and European Union has incremented the amount of renewable fraction inside automotive fuels obtained from lignocellulosic biomasses. In this work, the production of the advanced biofuel n-butyl levulinate (BL) from Arundo donax L. and industrial paper waste powder has been investigated. In particular, the direct acid-catalysed alcoholysis employing n-butanol as solvent/reagent and H2SO4 as homogeneous catalyst in the presence of microwave and traditional heatings has been optimized. With both the investigated biomasses, BL yields around 30 mol% have been achieved with high loadings of feedstock, 20 and 14 wt% for Arundo donax L. and paper waste powder, respectively, at 190 °C after 15 min, adopting microwave heating and H2SO4 loading of 1.2 wt%. Moreover, the employment of traditional heating has allowed us to achieve BL yields about 30 mol% with the low catalyst loadings of 0.6 and 0.4 wt% for Arundo donax L. and paper waste powder, respectively, at 200°C after 3h, adopting the same biomass loadings (20 and 14 wt%). Finally, a preliminary study of diesel engine performances and emissions regarding the potential application of the obtained mixture as additive for diesel fuel was successfully performed.