Hydrogenation of Palm Esters to Fatty Alcohols using Re/Nb/Al2O3 Catalysts

The catalytic hydrogenation of palm esters to obtain fatty alcohols using Re-x%Nb/Al2O3 catalysts was evaluated without solvents. The catalysts were characterized using nitrogen physisorption, X-ray Diffraction, X-ray Photoelectron Spectroscopy, Temperature-Programmed-Reduction, Pyridine-FTIR, and Temperature-Programmed-Desorption-NH3. The catalyst with a 10% Nb load was the one that obtained better performance when compared to the other catalysts with 5Nb and 20%Nb. The catalyst with 10%Nb obtained an average of 90% ester conversion and 79% selectivity in fatty alcohols. The design of experiments was made to understand the most important variable in the system. The results showed that temperature and pressure were the most critical factors. The better catalytic performance obtained employing the 10% Nb catalyst can be explained by its acidity properties. Moreover, this catalyst showed high stability in the deactivation assays. The results obtained in this work showed a promising method to obtain catalysts with high performance to produce fatty alcohols. Thermodynamic reasons (temperature and pressure) justify the slow conversion rate of wax esters to fatty alcohols for most reactions.