Heterogeneous catalytic hydrogenation of canola oil using palladium

The hydrogenation of canola oil was studied using palladium black as a potential catalyst for producing partially hydrogenated fats with low trans ‐isomer content. Pressure (150‐750 psig) appeared to have the largest effect on trans ‐isomer formation. At 750 psig, 90 C and 560 ppm metal concentration, a maximum of 18.7% trans isomers was obtained at IV 53. A nickel catalyst produces about 50% rans isomers at the same IV. For palladium black, the linolenate and linoleate selectivities were 1.2 and 2.7, respectively. The maximum level of trans isomers observed ranged from 18.7% to 42.8% (150 psig). Temperature (30‐90 C) and catalyst concentration (80‐560 ppm) affected the reaction rate with little effect on trans ‐isomer formation and selectivities. At 250 psig and 50 C, supported palladium (5% Pd/C) appeared to be twice as active as palladium black. At 560 ppm Pd, 5% Pd/C produced 30.2% trans (IV 67.5), versus 19.0% trans for palladium black (IV 68.9). Respective linoleate selectivities were 15 and 6.6, while linolenate selectivities were approximately unity. Analysis of the oil samples by neutron activation showedapproximately a 1 ppm, Pdresidue after filtration.