Hydrogenation of Cottonseed Oil with Nickel, Palladium and Platinum Catalysts

Eleven catalysts based on Ni, Pd, and Pt from two manufacturers were used for hydrogenating cottonseed oil, with the goal of minimizing trans fatty acid (TFA) content. Despite different temperatures, catalyst levels, and reaction times being used, the data from each catalyst type fell on the same curve when the TFA level was plotted against the iodine value (IV). Under low-pressure, high-mixing hydrogenation conditions, the Ni, Pd, and Pt catalysts all produced < 5% TFA and < 5% stearic acid at 95 IV; however, at 70 IV, only Pt catalysts produced 9% TFA and about 17% stearic acid. Kinetic modeling provided a better understanding of the relative reaction rates involved in hydrogenation. Pt catalysts converted linoleic and oleic acids more slowly to TFA and quickly hydrogenate TFA, thereby leading to low TFA levels. In comparison to other hydrogenated oils reported in the literature, equivalent or lower TFA and stearic acid levels were observed with hydrogenated cottonseed oil under the experimental conditions used.