Synergistic aminolysis–hydrolysis biomass by a dual-base system for concurrent high-purity carbohydrate streams and lignin amidation

The recalcitrance of lignocellulosic biomass, primarily due to lignin-carbohydrate complexes (LCCs), poses a major challenge for its efficient biorefining into biofuels, biochemicals, and biomaterials. Herein, we report a synergistic dual-base pretreatment system comprising sodium percarbonate (SP) and ethanolamine (ETA) for the selective fractionation of corn cob. This system effectively cleaves LCC ether and ester bonds via combined alkaline hydrolysis and nucleophilic aminolysis, enabling a hemicellulose-first fractionation strategy. Under optimal conditions (160°C, 1 h, 4% SP/40% ETA), a high hemicellulose yield of 55.30% (based on original content) with exceptional purity of 91.86% was achieved. Concurrently, the process generated a cellulose/xylan-enriched holocellulose residue with enhanced enzymatic digestibility and yielded a nitrogen-functionalized lignin stream bearing amide groups. This work presents a green and integrated approach for concurrent biomass fractionation and lignin valorization, offering new insights into sustainable lignocellulose biorefining.