Lignin-derived deep eutectic solvent for biomass fractionation based on α,γ-diol lignin stabilization strategy

Overcoming the biomass recalcitrance is crucial for thermal converting raw biomass into high-value chemicals. Consequently, the growing emphasis on sustainable and efficient pretreatment methods has become a key goal of research in the biorefinery field. This study proposes a novel lignin-derived deep eutectic solvent (LDES) pretreatment method to promote biomass pyrolysis based on α,γ-diol lignin stabilization strategy. It effectively deconstructed the complex biomass structure while significantly inhibiting lignin recondensation and undesirable deposition. This process achieved exceptional delignification (97.05 %) and hemicellulose removal (83.09 %), while maintaining 84.12 % of the cellulose, thus facilitating a high levoglucosan yield of 38.93 wt% in subsequent pyrolysis. Additionally, the isolated lignin had a low molecular weight (1873 g/mol) and well-preserved β-O-4 linkages (28.37/100Ar), rendering it ideal for the preparation of platform chemicals and lignin-based materials. This study highlights the potential of tunable and functional LDES as a promising pretreatment solvent, facilitating efficient fractionation and valorization of biomass, and achieving the concept of "closed-loop" biorefinery.