Structure-property-performance relationships of lactic acid-based deep eutectic solvents with different hydrogen bond acceptors for corn stover pretreatment

Herein, ten types of lactic acid-based deep eutectic solvents (DESs) with differently structured hydrogen bond acceptors (HBAs) were used for corn stover pretreatment. Among the tested DESs, those composed of HBAs with short alkyl chain were more effective to remove lignin and xylan, resulting in higher enzymatic digestion of the pretreated solids than their counterparts with long alky chain. Also, functional groups of HBAs demonstrated significant effects on biomass deconstruction. In order to interpret the different pretreatment performance of the tested DESs, Kamlet-Taft solvent polarity parameters of the tested DESs were correlated to their lignocellulose pretreatment performance. It was found that hydrogen bond acidity (Kamlet-Taft alpha parameter) had strong positive relationships with pretreatment efficacy of the studied DESs. These findings not only clarified the structure-property-performance relationships of the DESs, but also provided novel insights into design and selection of DESs for lignocellulose pretreatment.

Automated summary

This study investigated the pretreatment of corn stover using lactic acid-based deep eutectic solvents with varying hydrogen bond acceptor structures. The results showed that DESs with short alkyl chain HBAs were more effective in removing lignin and xylan and promoting enzymatic digestion. Additionally, the hydrogen bond acidity of the DESs was found to have a strong positive relationship with pretreatment efficacy, providing insights into the design and selection of DESs for lignocellulose pretreatment.