LAUSR

Pretreatment with efficient fractionation, eco-friendliness, and low-cost brings high-security to future biorefinery systems. Synergistic pretreatment is a compelling blueprint to tackle the compact structure of lignocellulose towards a high-level valorization. We designed a stepwise approach, using hydrothermal and deep eutectic solvent (DES) pretreatments, to hierarchically extract hemicelluloses and lignin from poplar, while delivering a cellulose-rich substrate that can be easily enzymatic hydrolysis to obtain fermentable glucose and residual lignin. The lifetime of novel DES showed that the pretreatment efficiency was still largely maintained after the fourth recycling. An enhancement of enzymatic digestibility from 13.9 to 90.4% was initiated by the deconstruction of amorphous portions and robust cell wall. An ally of 23.7% xylooligosaccharides (degree of polymerization, DP 2-6), 47.5% DES-isolated lignin and 19.2% cellulose enzymatic lignin was harvested via this coupled process. It was reasonable to push forward the precise design of sustainable tandem pretreatment that can boost the frontier of highly available biorefinery.