Catalytic deoxygenation of tall oil fatty acid over palladium supported on mesoporous carbon

Catalytic deoxygenation of tall oil fatty acids (TOFAs) was investigated over 1 wt % Pd/C Sibunit, which is a synthetic mesoporous carbon. The reactions were performed in a semi-batch reactor using dodecane as a solvent under 17 bar of total pressure. The main studied parameters were the reaction temperature, initial concentration of TOFA, effect of the reaction atmosphere, and metal loading. The temperature and initial concentration ranges were 300-350 °C and 0.15-0.6 mol/L, respectively. The total conversion of fatty acids increased, as expected, with increasing temperatures and decreasing initial TOFA concentrations. The main liquid-phase products were n-heptadecane and n-heptadecene. In addition to the desired linear C₁₇ hydrocarbons, also aromatic C₁₇ compounds, such as undecylbenzene, were formed. The best conditions for the formation of the desired C₁₇ hydrocarbons were lower initial concentrations of TOFA, 300-325 °C, and the presence of hydrogen. An increase of the metal loading (4 wt %) led to an increase of the selectivity to linear C₁₇ hydrocarbons.