An integrated biorefinery strategy for dual valorization of xylose residue unlocks high-yield glucose and fully lignin-based adhesives

The sustainable biorefinery of lignocellulosic biomass (LCB) is pivotal for a circular bioeconomy, yet conventional fractionation often requires harsh conditions that compromise lignin functionality and carbohydrate integrity. Here we report an integrated strategy for dual valorization of industrial xylose residue (XR) by combining a mild alkaline hydrogen peroxide (AHP) pretreatment with pH-dependent lignin fractionation. Under 2 wt% AHP (pH 11.5, 60 °C, 1 h), the pretreatment achieved 90.04% delignification while producing a cellulose-rich residue that delivered a glucose yield of 98.12% at 5 wt% solids (10 FPU/g, 100 mg/g and 48 h), corresponding to a glucose concentration of approximately 45.90 g/L (16.98 and 78.52 g/L at 2 and 10 wt% solids, respectively). Crucially, the recovered lignin fractions retained key near-native, non-condensed structure and possesses reactive functionalities, enabling versatile lignin valorization including lignin nanoparticles, antioxidant performance, and a fully lignin-based adhesive formulated by water-only adjustment (25 wt% solids) that exhibited excellent dry and wet bonding strengths of 2.69 MPa and 1.24 MPa, respectively, exceeding the Chinese national standard. In summary, this work establishes an integrated and sustainable biorefinery paradigm for the valorization of agricultural and forestry wastes into fermentable sugars and high-performance fully lignin-based adhesive.