Efficient depolymerization of lignin in supercritical ethanol by a combination of metal and base catalysts

Abstract

This study investigates the use of combination of metal and solid-base catalysts for effective depolymerization of lignin into monophenol-rich bio-oil in supercritical ethanol through a synergy of base-catalyzed solvolysis and metal-catalyzed hydrogenolysis. The results showed that a combined catalyst of Ru/C and MgO/ZrO2 resulted in a significant decrease in the molecular weight of bio-oil, an increase in the yield of phenolic monomers, and the improved deoxygenation degree of bio-oil compared to the single catalyst condition. The synergic role of metal and base catalysts during lignin depolymerization was examined through comprehensive analysis of reaction products. (c) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.