Plasma-Enabled Liquefaction of Cellulose and Lignin as Lignocellulosic Biomass Model Compounds

Low-temperature plasma has shown the promising performance in biomass liquefaction with short liquefaction time and high liquefaction yield. In this study, we investigated the performance of plasma-enabled liquefaction of cellulose and lignin as lignocellulosic biomass model compounds. Different cellulose-to-lignin mass ratios were set to determine the optimum condition from the viewpoints of biomass raw materials. Elemental analysis, infrared spectroscopy, thermogravimetric analysis, and gas chromatography–mass spectrometry were performed to analyze the solid residues and liquid products obtained under optimum condition. Results showed that the highest liquefaction yield (98.8%) was achieved at a cellulose-to-lignin mass ratio of 2/3 and a liquefaction time of 3 min. Abundant hydroxyl groups, as well as functional groups such as carbon–hydrogen bonds and carboxyl groups, were detected in the liquid products. The liquid products contained a rich variety of alcohols, along with traces of organic acids, lipids, and aromatic compounds. These liquid products exhibit a promising potential to act as the cleaning fuels.