Highly selective hydropyrolysis of lignin waste to benzene, toluene and xylene in presence of zirconia supported iron catalyst
William Lonchay, Giuseppe Bagnato, Aimaro Sanna
Abstract
The use of lignin to produce Benzene, Toluene and Xylene (BTX) is a promising pathway to strength the economic case, over the production of advanced bio-fuels alone. In this work, Ce, Na, Pd and Fe supported on zirconium oxide were evaluated for the ex-situ hydropyrolysis (HyPy)/hydrodeoxygenation (HDO) of Etek lignin under mild conditions (600 °C, 1 atmosphere) towards the production of BTX. Fe/ZrO2 was able to selectively produce BTX (67 area%) and cycloalkenes (13.5 area%) and strongly deoxygenate the HyPy oil to about 5 wt% oxygen content, resulting in an oil with a carbon distribution of 85.5 % in C5-C10 hydrocarbons. The high selectivity of Fe/ZrO2 was related to the iron oxophilicity, the strong reduction potential of zero-valent iron, the good dispersion of Fe nanoparticles on the support and the presence of mesopores and acid sites, which enhanced the interactions between the reacting species and the catalyst surface.