Kinetic modeling of fatty acid methyl esters and triglycerides hydrodeoxygenation over nickel and palladium catalysts

The kinetics of fatty acids methyl esters (FAME) and triglycerides (TG) hydrodeoxygenation (HDO) over 5 wt% Ni/H-Y-80 and 5 wt% Pd/C catalysts into green-diesel range hydrocarbons was studied experimentally and modeled numerically. The liquid-phase HDO was performed in a semi-batch reactor at the reaction temperature of 300 °C and pressure 30 bar on a sulfur free nickel supported catalyst and a palladium catalyst for comparison.The fit of the model was evaluated by comparing the concentration profiles obtained from the model with the experimental data. The model confirmed that a complete reaction network involves hydrogenation, decarboxylation/decarbonylation and the direct hydrodeoxygenation of FA. Overall, the model displayed a good fitting for both studied substrates. Moreover, the model is expected to be applicable to different fatty acids. The rate constants for the conversion of FAME and TG, containing mixture of two groups of molecules C:16 and C:18, show dependence on the fatty acids carbon chain length.