PERSPECTIVES ON THE USE OF AGRO-FOOD WASTES AND GREEN SOLVENTS PRETREATMENT TO MEET BIO-BUTANOL DEMAND IN EUROPE

In the last years, first generation biofuels (FGBs) have been overtaken by second generation biofuels (SGBs). Among the difference between FGBs and SGBs, the severity of biomass pretreatment step has been addressed in order to design environmental friendly and energy saving processes aimed at the recovery of sugar fractions from the lignocellulosic feedstock. Moreover, the issue related to the biomass availability in European countries has been addressed by several reviews in the literature even though, to our knowledge, no studies related to the amount of organic waste coming from the food industrial sector have been published so far. Among the novel green processes proposed for biomass pretreatment, lignin extraction with Deep Eutectic Solvents (DESs) seems to be a promising alternative for biomass dissolution and fermentable sugars recovery thanks to their physicochemical properties similar to that of ionic liquids (IL). In addition, use of DESs is less energy consuming and they are more environmental friendly and inexpensive than ILs. This paper reports a survey of several industrial Agro-Food Wastes (AFWs) available in Europe for the production of butanol as SGB. Data on biomass availability and composition were retrieved for each AFW and combined with experimental results reported in the literature on the butanol yield obtained after AFW pretreatment with DES and ABE fermentation of the sugar fraction. The results provided the potential butanol production rate for the whole set of AFW considered and were compared to the European biofuel demand.