Enhanced Fractionation of Woody Biomass and Efficient Valorization via Ternary Acid-Organic Solvent System

Two triad acid-organic solvent pretreatment system (HTC and HTE) based on phosphoric acid, p-toluenesulfonic acid, and organic solvent of n-butanol/2-phenoxylethanol were used in this study to achieve excellent fractionation efficiency. Specially, under ideal mild conditions (120 ℃, 60 min), the HTE system efficiently removed 90.68% of hemicellulose and 98.56% of lignin while keeping a low cellulose loss of 2.12%.

The glucose yield increased from 5.02% of the raw material to 89.8% in cellulose-rich solid residue, signifying a 17.9-fold increase. Furthermore, 84.22% and 87.09% lignin was recovered in HTC and HTE organic phase, with high purity of 91.29% and 89.92%, respectively. Notably, this pretreatment strategy produced practically full fractionation effects from poplar, and the platform sugars and compounds were easily isolated and purified.