Pressurized steam torrefaction of wet agro-industrial residues

This paper aims at demonstrating the viability of pressurized steam torrefaction (PST) as an effective pretreatment of wet agro-industrial residues for a flexible generation of biochar, along with secondary liquid products as “green” feedstocks of interest in chemical and process industries. A comprehensive experimental investigation program is presently going on at a laboratory scale by testing two wet agro-industrial residues typical of Italian agro-food sector, i.e., tomato peels and olive husks, produced in the Campania region (Italy). As a complement to the batch pressurized treatment in presence of water, the addition of a simple and cheap catalytic material has been taken into consideration during the torrefaction stage, and before the subsequent stage of solvent extraction of chemicals from the non-volatile torrefied products. This article reports the work-in-progress results, which are in the direction of boosting and upgrading the produced liquid fraction.