Oxygen-driven ethanolamine pretreatment for one-pot functional recovery of in situ aminated lignin and efficient enzymatic glucose production.

Abstract

The efficient pretreatment of waste biomass to achieve effective carbohydrate conversion and high-value lignin valorization has consistently been regarded as one of the most critical challenges in the field of biomass refining. In this study, an oxygen-driven ethanolamine (OE) pretreatment strategy was developed using reed as the feedstock, enabling efficient carbohydrate recovery while simultaneously driving lignin structural transformation and in situ nitrogen functionalization via a coupled oxidative ammonolysis pathway. Under the selected pretreatment conditions (85 wt% ETA, 1 MPa O2, 170 °C, 30 min), the OE system achieved highly efficient biomass fractionation. Cellulose retention exceeded 90 %, while the delignification rate reached 82.57 %, substantially enhancing cellulose enrichment and enzymatic accessibility. As a result, enzymatic hydrolysis delivered a glucose yield as high as 92.36 %. Meanwhile, the nitrogen-functionalized lignin preserved most of the native lignin side-chain architecture, which confers superior practical application potential compared with highly condensed traditional kraft lignin. Overall, the OE system represents a synergistic fractionation strategy integrating efficient cellulose preservation, enhanced enzymatic hydrolysis, and functionalized lignin recovery. This work provides a new perspective for sugar-platform construction and lignin valorization in the green biorefining of lignocellulosic biomass.