Homogeneous catalytic hydrogenation of canola oil using a ruthenium catalyst

Dichlorodicarbonylbis (triphenylphosphine) ruthenium (II), RuCl 2 (CO) 2 (PPh 3 ) 2 , was investigated as a catalyst for edible oil hydrogenation in a preliminary screening of potential catalysts for producing partially hydrogenated fats with low trans ‐isomer content. Refined, bleached and deodorized canola oil was hydrogenated using 1.77 × 10 −5 − 6.64 × 10 −4 mol/kg‐oil of ruthenium catalyst equivalent to 1.79 × 10 −4 − 6.71 × 10 −3 wt% Ru. The effects of temperature (50–180 C) and pressure (50–750 psig) on reaction rate, trans ‐isomer content and fatty acid composition were examined. The activities of RuCl 2 (CO) 2 (PPh 3 ) 2 and nickel (Nysel HK‐4 and AOCS standard nickel catalyst) were compared on a molar basis. At 4.40 × 10 −4 mol/kg‐oil (0.0026 wt/Ni or 0.0044 wt% Ru), 140 C and 50 psig, the nickel catalysts were completely inactive, but the ruthenium catalyst produced an IV drop of 40 units in 60 min. At 110 C, 750 psig and 1.34 × 10 −4 mol/kg‐oil (1.35 × 10 −3 wt% Ru), a hydrogenation rate of 0.89 ΔIV/min and a maximum trans ‐isomer content of 10.4% (IV=45.0) was obtained with the ruthenium catalyst.