Kinetics of the hydrogenation of sunflower oil over alumina supported palladium catalyst

The present work studies the sunflower oil hydrogenation on supported palladium catalysts, by analyzing the surface kinetics and the mass transfer limitations of products and reactants. Initially, a simplified model was studied. This model took into account only the consecutive hydrogenation of linoleic acid (diene), to reach the production of oleic (monoene) and stearic (saturated) acids. Using the adjusted values of the kinetic constants and the activation energies of the hydrogenation obtained with this model, a new scheme was investigated considering the geometric isomerization reactions (cis-trans). The diene hydrogenation constant was larger than that of the monoene. This fact confirms the higher reaction rate of the diene hydrogenation in comparison with that of the monoene. With respect to the isomerization rates, these have an activation energy superior to that of the monoene hydrogenation, and slightly superior to the diene hydrogenation activation energy. This fact verifies the influence of temperature on the formation of trans-isomers. Copyright © 2007 The Berkeley Electronic Press. All rights reserved.