Lignin Valorization for Added-Value Chemicals: Kraft Lignin versus Lignin Fractions

Lignin is a raw material that can potentially be converted into valuable compounds through depolymerization reactions in addition to its use as polymer or material. However, the chemical recalcitrance and heterogeneous composition structure of lignin make it challenging establish processes add value this complex aromatic biopolymer. In work, solvent fractionation was applied obtain fractions with narrowed molecular weight specific structural characteristics, improving homogeneity purity. A kraft submitted using different ratios acetone, ranging from 60 15% v/v, aqueous mixtures. The composition, structure, each fraction were studied their potential applications evaluated. most water-soluble has more phenolic OH, less aliphatic OH groups, shows lowest content aryl-ether linkages, which accordance highest degree condensation. On other hand, insoluble mixture 60% acetone inorganic Radar plots for evaluation (IF 30:70) alkaline oxidation O2. results compared products yielded lignin. An increase about 13 19% found vanillin syringaldehyde, respectively, when IF 30:70 oxidation. conclusion, proposed process showed an effective method characteristics could improve source high added-value monomeric compounds.