Cis selectivity of mixed catalyst systems in canola oil hydrogenation

Abstract

Two mixed catalyst systems were investigated for their suitability to produce partially hydrogenated canola oils with low levels of trans fatty acids. Each system included a homogeneous catalyst paired with a heterogeneous catalyst. Cl 2(CO) 2(PPh 3) 2Ru(II) was combined with Ni, while methyl benzoate chromium tricarbonyl [MeBeCr(CO) 3] was paired with Pd. The effect of changing the catalysts’ molar ratios and the reaction conditions on activity, specific isomerization index, linoleate and linolenate selectivities and fatty acid compositions was evaluated in an effort to identify synergies related to differences in the hydrogenation reaction mechanisms of the two components. Only the Ru and Ni combination proved to be advantageous. At 110 °C and 5.2 MPa, the activities of the Ni/Ru mixtures were higher than the activities of the catalysts used individually, and low levels of trans isomers (∼9%), characteristic of the Ru catalyst, were observed.