(63d) Lignin Depolymerization in Ionic Liquids with the Presence of Hydrogen Transfer Agents

Biofuels production from lignocellulosic biomass will reduce the nation’s reliance on imported fossil fuels and yield economic benefits.  Lignin conversion is the bottleneck of fully utilization of lignocellulosic biomass. In this paper, a lignin conversion method is presented, in which lignin was dissolved in ionic liquids and catalytically depolymerized in presence of hydrogen generated from hydrogen transfer agents. Kraft lignin and lignin extracted from pine wood were successfully depolymerized to phenols and substituted phenols at over 50% yields. The results include: a) the reaction temperature at 200°C or above is preferred for lignin depolymerization; b) different metal oxides were used as catalysts for lignin depolymerization; 3) the lignin depolymerization was also compared with water as solvent for kraft lignin depolymerization.  

Further catalytic hydrodeoxygenation of the phenolic compounds produces hydrocarbons which are fuel components and can be blended into gasoline.