Abstract

This study presents a pioneering approach in the fractionation of Eucalyptus globulus pinchips with different humidity (0–79%) by using an alkaline Deep Eutectic Solvent (DES) of potassium carbonate and glycerol achieving the impact of water on the delignification process. This type of solvent is derived from ionic liquids, which are structurally sensitive to the presence of water, as it can dissociate the DES network and affect its efficacy in biomass fractionation. Consequently, authors reported the need to use anhydrous biomass when fractionation with DES. This research demonstrates that it is possible to delignify hydrated samples using alkaline DES of potassium carbonate and glycerol (ratio 1:4) at 6 wt% solids, 130 °C, 24 h, and 400 rpm. Eucalyptus globulus pinchips with up to 20% humidity achieved up to 87.8 ± 0,1% of delignification. Notably, saturated pinchips (79% humidity) only reduced its delignification efficiency by 3%, validating the process`s robustness. The solid and liquid fraction composition did not show differences between reaction conditions. This treatment approach eliminates the need for prior drying or thermal modification of biomass, offering competitive and efficient results and positioning itself as a promising methodology in the biomass fractionation industry.