Influence of the operating conditions and kinetic analysis of the selective hydrogenation of oleic acid on Ru-Sn-B/Al2O3 catalysts

Abstract

The influence of the operating conditions on the selectivity and activity of Ru-Sn-B/Al2O3 catalysts for the hydrogenation of oleic acid to oleyl alcohol was studied. It was found that the Ru-Sn-B/Al 2O3 catalyst is selective to oleyl alcohol while Ru or Ru-B/Al2O3 catalysts are not selective to produce oleyl alcohol. The electronic and catalytic properties of Ru are modified by the strong interaction between Sn and B. The incorporation of Sn leads to catalysts capable of producing oleyl alcohol. The experiments of oleic acid hydrogenation showed that an increase in reaction temperature leads to an increase in activity while the selectivity to oleyl alcohol goes through a maximum. This is because the reactions of hydrogenation of CC double bond have lower activation energies than hydrogenolytic reactions. The increase in operating pressure has a positive effect on conversion and a more important effect on selectivity. A very simple first order kinetic model is proposed and reasonably represents the results obtained. This model can be useful to compare catalyst performance more rationally.