ReFuel involves two research units at POLITO and UNIPA with strong competence in the study of hydrothermal conversion of residual biomasses. Through their synergetic collaboration, the project aims at deepening the study of the fundamental mechanisms underlying pretreatment and hydrothermal conversion of residual biomass. A main goal of ReFuel is to understand the correlation between pretreatments in the presence of different additives (sulphuric acid, formic acid, potassium hydroxide, sodium hydroxide) as well as the recalcitrance and chemical reaction paths of a real biofeedstock in hydrothermal liquefaction (HTL). One further goal is to assess if pretreatments can be used to stabilize HTL performances in spite of the intrinsic time variability of composition of real feedstock such as the organic fraction of municipal solid waste (OFMSW).

A first specific feature of the project is the study of the effect of acid or basic hydrolytic pretreatment on the performances of HTL of model compounds as surrogates for real biofeedstock. Working with these systems under controlled operating condition enables better identification and understanding of the reaction pathways and of any possible synergies resulting from co-processing of multiple substrates. A second specific feature of the project, consistent with and complementary to the first one, is represented by the development of a unified vision and interpretative framework of an effective pretreatment/HTL sequence. The ambitious long-term goal is the development of a sound and cheap methodology apt to mitigate the effects of not stable composition of recalcitrant bioresources such as OFMSW by transfer of heteroatoms from the feedstock to a suitable pretreatment aqueous phase.