Valorization of Pinus pinaster wood by one-pot treatments in butanol/water biphasic mixtures

Abstract

Biphasic butanol/water treatments have been proposed for the efficient fractionation of Pinus pinaster wood, with the objective of recovering glucan enriched solid phases, and two liquid streams, one organic and one aqueous, mainly made up of lignin-solubilized products and hemicellulosic compounds, respectively. Under selected operating conditions (190ºC, 40% of butanol, 1% of catalyst, and 10 min), high lignin solubilization (77.82%) and glucan recovery (86.93%) were achieved and an aqueous phase containing 15.8 g/L of oligosaccharides was also obtained. Further processing of the organic phase allowed the recovery of 62.69% of the initial lignin with a high purity (close to 94%). Finally, the enzymatic digestibility of the treated solid was evaluated achieving a saccharification yield of about 95%. Therefore, a promising softwood biorefinery scheme based on the use of a hydrophobic green solvent is proposed.