earticle

영어

Biomass fractionation is one of the critical steps to obtain cellulose rich residue, lignin, and hemicellulose main components in the integrated biorefinery process. Furthermore, a deep understanding of all the three major components structural changes during the fractionation process will facilitate their further high-value applications. In order to better understand whether the lignin structure has changed, microwave-assisted deep eutectic solvent extraction of lignin from spruce sapwood and heartwood was explored. Various structural analyses of lignin fractions were performed by different methods including 2D HSQC, 31P NMR, SEC/MALS, and FTIR. The results show that the yield of lignin of heartwood and sapwood in only 10 min can reach 68% and 65%, respectively. 2D HSQC and FTIR results also show that the lignin fraction from heartwood and sapwood has a similar linkage and structure. A similar lignin fraction would be obtained by DES fractionation, which increases understanding of sapwood and heartwood for further development. The relatively high yield also will be attractive for boosting its applicability in functional materials.