Catalytic Liquefaction of Kraft Lignin with Solvothermal Approach

Lignin is a natural biopolymer present in lignocellulosic biomass. During paper pulp production with the Kraft process, it solubilized and degraded lignin then burned to recover energy. In this paper, solvolysis of was studied water water/alcohol mixtures produce oligomers monomers interest, at mild temperatures (200–275 °C) under inert atmosphere. It found that presence alcohol type (methanol, ethanol, isopropanol) greatly influenced amount formed from lignin, reaching maximum 48 mg·glignin−1 isopropanol as co-solvent. The impact addition various solid catalysts composed metal phase (Pd, Pt or Ru) supported on an oxide (Al2O3, TiO2, ZrO2) investigated. water, yield enhanced by catalyst particularly Pd/ZrO2. However, alcoholic co-solvent, only formation oligomers. Detailed characterizations products FTIR, 31P-NMR, 1H-NMR HSQC NMR were performed elucidate chemical transformations occurring during solvolysis. nature active catalytic specie also investigated testing homogeneous palladium catalysts.