(663d) Mechanism Study of Noble Metal Catalyzed Upgrading of Lignin Derived Pyrolysis Oil

Lignin is the second most abundant natural polymer in the world. However, unlike cellulose and hemicellulose, over 98% of lignin is simply burned for heat energy. Pyrolysis is recognized as one of the most economical ways to convert solid lignin to liquid oil. However, the oil products from this process cannot be directly used as a fuel. The major problems are instability, high acidity and low heating value. Therefore, upgrading the lignin pyrolysis oil is one of important steps in converting lignin to biofuel. In this research, palladium, platinum, rhodium and ruthenium were used as active metal in catalyst. Palladium and platinum showed no reactivity with the pyrolysis oil. Ruthenium was the only catalyst which is able to produce fully hydrogenated and intensively deoxygenated products. Guaiacol was adopted as model compound to study the reaction mechanism of the oil upgrading. The result revealed that palladium and platinum were incapable of both hydrogenation and deoxygenation reaction with guaiacol due to the deactivation of catalyst. On the other hand, ruthenium was able to achieve both reactions. Related kinetics study showed different reaction path and reactivity for ruthenium and rhodium with the model compound.