| 초록 |
A molecular hydrogen free, non-catalytic route for efficient depolymerization of Alkali lignin into high yield aromatic monomers was studied in the presence of supercritical ethanol and formic acid. The role of a solvent, its consumption and reactivity was explored in details in the presence of some commonly used molybdenum and nickel based hydrocracking/ hydro-deoxygenating catalysts. The presence of these catalysts increased H-donation ability of ethanol for lignin depolymerization, but at the same time the ethanol self- reactivity was also enhanced, which in turn increased ethanol consumption to 41 wt %. The addition of formic acid not only decreased ethanol consumption to 4 wt% but the in-situ hydrogen generated form formic acid also led to complete conversion of alkali lignin at 350 °C, at short reaction time of 60 min, affording the high yield of aromatic derivatives (367.3 g/g of lignin). Further increasing reaction time led to the secondary reactions producing highly alkylated species in the product mixture which in turns decreased the lignin derived monomers yield of selected compounds. |
