(737f) Catalytic Hydrodeoxygenation of Guaiacol

Pyrolysis of biomass is a promising technology to convert solid biomass into liquid bio-oil. However, bio-oils have high water and oxygen content which subsequently lowers their energy density relative to conventional hydrocarbons. For this reason, an upgrading process is required. Catalytic hydrodeoxygenation (HDO) is a rapidly developing technology for achieving oxygen removal from bio-oils. While various catalysts have been studied for this purpose, due to the presence of more than 400 oxygenated organic compounds, the catalytic activity and reaction pathways in the HDO process are not well understood. In this context, it is important to select model compounds which represent the raw bio-oil. In this study, Guaiacol, a phenol derived compound produced by the thermal degradation of lignin, is selected as a model compound, because it is one of the major components of bio-oil and, in addition, is thermally unstable and leads to coke formation. Conducted in a fixed-bed reactor, this work identifies the optimum noble metal catalyst(s) along with the optimum operating conditions which minimize hydrogen consumption while maximizing oxygen removal. Further, the HDO reaction kinetics are measured and, based on analysis of both the liquid and gas the gas phase products, the reaction pathways are proposed.