Lignocellulose fractionation is a critical step in biomass valorization, enabling the efficient conversion of biomass into high-value products. Deep eutectic solvents (DESs) have emerged as promising green solvents for this purpose. However, conventional DES-based approaches often suffer from the poor recovery of hemicellulose, which tends to remain in the DES matrix, resulting in the loss of resources and value. In this study, a hydrophobic DES (HDES)-mediated biphasic system was developed for one-pot fractionation of lignocellulosic biomass. By coupling HDESs with an acidic aqueous phase, efficient and selective partitioning of biomass components was achieved by extracting lignin and hemicellulose into separate phases, facilitating the simultaneous recovery of multi-components. Notably, the process exhibited a high removal efficiency of multiple components and significantly improved the enzymatic saccharification efficiency of the residual cellulose-rich fraction. Furthermore, the mechanism of this fractionation process was comprehensively analyzed using various analytical techniques, including Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, X-Ray Powder Diffraction, Gel Permeation Chromatography, and Nuclear Magnetic Resonance Spectroscopy. These findings contribute to the development of more effective and sustainable biomass pretreatment methods for biorefinery.
