Recent advances in organosolv fractionation: Towards biomass fractionation technology of the future

Organosolv treatment is among the most promising strategies for valorising lignocellulosic biomass and could facilitate the transition towards enhanced utilization of renewable feedstocks. However, issues such as inefficient solvent recycle and fractionation has to be overcome. The present review aims to address these issues and discuss the role of the components present during organosolv treatment and their influence on the overall process. Thus, the review focuses not only on how the choice of solvent and catalyst affects lignocellulosic fractionation, but also on how the choice of treatment liquor influences the possibility for solvent recycling and product isolation. Several organic solvents have been investigated in combination with water and acid/base catalysts; however, the lack of a holistic approach often compromises the performance of the different operational units. Thus, an economically viable organosolv process should optimize biomass fractionation, product isolation, and solvent recycling.