COMPLETE EXPLOITATION OF EUCALYPTUS NITENS: OPTIMIZATION OF HYDROTHERMAL CONVERSION OF ITS CELLULOSE FRACTION TO LEVULINIC ACID AND BUTYL LEVULINATE

Abstract

The fractionation of the structural components of biomass and the valorization of each resulting fraction for specific purposes enable the development of sustainable processes for biomass utilization, according to the perspective of an integrated biorefinery. In this work, ADW (autohydrolysed-delignified Eucalyptus nitens wood) was employed as cheap cellulose-source. This cellulose-rich feedstock was used for the production of levulinic acid in water and butyl levulinate in n-butanol, adopting in both cases a dilute acid catalyst. The effects of the main reaction parameters on the catalytic performances to the target products were investigated and optimized. Under the best reaction conditions, employing microwave irradiation, both target products were obtained at promising yields: in water (180 °C, 20 minutes, HCl), levulinic acid yield accounted for 65 mol%, value higher than those reported in the literature for similar types of ADW biomasses, whereas, in n-butanol (190 °C, 15 minutes, H2SO4), butyl levulinate yield up to 30 mol% together with concentration of 54 g/L were reached, starting from the initial biomass loading of 20 wt%, values never reached for this reaction, thus opening the way towards its real applications