Effective biomass fractionation and lignin stabilization using a diol DES system

A sustainable and renewable biorefinery will increase the economic viability of lignocellulose-derived products. In this study, a diol-based deep eutectic solvent (DES) was developed to reduce the recalcitrance of bamboo, facilitate saccharification and valorize the lignin fraction. The DES pretreatment dramatically enhanced glucan digestibility by the effective removal of lignin (as high as 85.45%) and xylan (91.12%). Notably, the recovered lignin from DES pretreatment was protected during the fractionation, showing well-preserved 8-O-4 structures (31.82%-59.06%). The mechanism of lignin protection was analyzed to be accomplished by incorporating the diol hydroxyl functional groups into the alpha position of the lignin 8-O-4 structure via etherification. This study highlighted that diol DES is a promising pretreatment solvent to valorize both cellulose and lignin fractions with high enzymatic hydrolysis yield and high-quality lignin co-product.

Automated summary

In this study, a diol-based deep eutectic solvent (DES) was developed to improve the saccharification of bamboo and valorize the lignin fraction. The DES pretreatment effectively removed lignin and xylan, resulting in enhanced glucan digestibility. The recovered lignin from DES pretreatment showed well-preserved 8-O-4 structures, indicating the potential of diol DES as a promising pretreatment solvent for cellulose and lignin conversion.