LAUSR

Abstract In this study, hydrodeoxygenation reaction is conducted without using hydrogen as a feed. The required hydrogen was provided in situ through plasma decomposition of methoxyl and methyl radicals which exist in the chemical structure of lignin pyrolytic-oil at room temperature. Operating parameters including applied voltage, Ar flow rate and discharge length were carefully studied in order to maximize the conversion and degree of deoxygenation. A guaiacol conversion of 81% and deoxygenation degree of 52% were achieved at an applied voltage of 12 kV and a discharge length of 20 cm without using any catalyst and hydrogen. By optimizing discharge length and Ar flow rate, conversion increase by 36% and power consumption reduced by 33%. Unlike previous studies in which catechol was produced as a major product, in this study phenol is produced selectively through direct demethoxylation rather than demethylation reaction. Due to operation at low temperature and atmospheric pressure no hydrogenation of aromatic ring was observed. Results show that the non-thermal plasma is capable for the upgrading of guaiacol and may pave the way towards the hydrogen-free hydrodeoxygenation reaction.