Selective hydrogenation of soybean oil: IX. Effect of pressure in copper catalysis

Abstract

AbstractSelective hydrogenation of soybean oil with copper catalyst at 50 psig or less is characterized as a relatively slow reaction requiring higher catalyst concentrations than the less selective but rapid nickel‐catalyzed reactions used in most commercial practice. Hydrogenations of soybean oil have been performed which included a high‐pressure scan (500, 1000, and 3000 psig), at selected temperatures (110, 130, 150, and 170 C), and at specific catalyst concentrations (0.05, 0.1, 0.2, and 0.4% copper). Selectivities, relative reaction rates, and geometric and positional isomerization have been determined as an evaluation of the effects of high pressure on the kinetics of the reaction. The experimental results indicate that an appropriate selection of pressure, temperature, and catalyst concentration can permit: (a) a significant increase in the rate of reaction while retaining the high linolenic acid selectivity of copper catalysts, (b) use of lower concentrations of copper catalyst while maintaining the higher reaction rate, and (c) elimination of conjugated diene as a measureable product in the hydrogenated oil.