Abstract
Triolein was hydrogenated under various operating conditions. Five types of catalysts were employed. Platinum and palladium catalysts were used at 50°C and each of three types of nickel catalyst was used at 160°, 180°, 200° and 220°C. The hydrogenated products were subjected to lipase hydrolysis (lipolysis) to remove a portion of the acyl groups on the α, α'-positions. The hydrogenated products and fatty acids liberated by lipolysis were analyzed for fatty acid compositions and for content of the trans isomers.
In case of nickel boride catalyst, the results showed that the oleoyl groups on α, α'-positions of triolein molecule are hydrogenated slightly faster than that on β-position. The other catalysts have not shown the selectivity of hydrogenation toward the position of acyl groups.
There was no relation to be discussed between the position of acyl groups and the formation of trans isomers during hydrogenation with each nickel catalyst. Upon comparison at the same iodine value, trans isomer content in hydrogenated products was the most in case of nickel boride catalyst.
