(282d) Fractionation, Characterization and Value-Addition of Endocarp Lignin

The lignin-rich endocarps have distinct structural characteristics from woody and herbaceous biomass that attribute to their and tightly packed cell walls. We characterized the endocarp biomass and identify features of this unique feedstock relevant to feedstock preprocessing, logistics, and valorization. Nanoindentation showed that endocarp biomass has high hardness and elastic modulus which indicates its high resistance to deformation. The energy consumed during size reduction of endocarps depends on the intended particle size and requires less energy with increasing screen size. Despite differences in lignin removal and sugar yield, both deep eutectic solvent and alkaline pretreatment-derived lignins were equally efficient in synthesizing a carbon-silicon nanoparticle composite for prolonged anode life cycle of lithium-ion batteries. Morphological and structural characterization of the lignin derived composite materials suggest that the carbon coating layer on the silicon NPs helps to alleviate the stress and enhance the mechanical property of the anode during charging and discharging. The high-value electrode material represents a promising valorization pathway for endocarp lignin, which could greatly improve the economic efficiency and sustainability of a biorefinery using endocarp biomass as feedstocks.