Study On Hydrogenation Of Soybean Oil By Pricat Ni Catalysts

In this study ,we used soybean oil as material, evaluated three kinds of Pricat Ni catalyst in common use of hydrogenation; investigated the technical conditions of full hydrogenation of soybean oil and then researched the effect of selective hydrogenation conditions on the species and contents of trans fatty acids.The main results are as follows:The catalyse activities of three kinds of Ni catalysts are 9920>9910>9908.When use 9908 catalyst hydrogenating soybean oil,the products have steeper curve of solid fat contents which can be used as cocoa butter replacement.While the hydrogenated fats that hydrogenated by 9910 and 9920 catalysts have wide range of plasticity and suit for used as raw materials of margarine and shortening.The 9920 catalyst suit for producing full hydrogenation stearin. The contents of Trans C18:1 with various catalyst ratios show that the content of TFA during the process of hydrogenation lie on the kind of catalyst, the effect of catalyst concentration is little.The pressure of hydrogen is the most factor affect rate of full hydrogenation ,then temperature of hydrogenation and catalyst concentration. Increasing the pressure of hydrogen,the rate of full hydrogenation almost enhance linear; whereas the rate of full hydrogenation increase slowly when increase the temperature of hydrogenation and catalyst concentration,and then the rate of full hydrogenation will decrease when the temperature of hydrogenation and catalyst concentration increased more. The optimization conditions of full hydrogenation of soybean oil were as follows: pressure of hydrogen is 0.3MPa, temperature of 190℃and catalyst concentration of 0.10%.Under selective hydrogenation conditions, temperature of hydrogenation is the main reason for the form of TransC18:1-6~8t. At low temperature of hydrogenation , the contents of TransC18:1-9t was more than other isomers of TransC18:1 obviously, TransC18:1-6~8t was didn't detect. Increasing the temperature of hydrogenation, The contents of TransC18:1-6~8t increased remarkably whereas the contents of TransC18:1-9t reduced. At higher temperature of hydrogenation ,the trends of changing of main TransC18:1 isomers were similar. The contents of TransC18:1-12t and TransC18:1-13/14t were increased during the process of hydrogenation in nine experiments.The solid fat content (SFC)of hydrogenated fats increase along with the content of trans fatty acids and also affected by the contents of all kinds of isomers.