Hydrogenation of soybean oil with commercial copper-chromite and nickel catalysts: Winterization of low-linolenate oils

Abstract

Soybean oil hydrogenated in the presence of copper-chromite catalysts to 3% linolenate and below requires winterization if it is to pass the cold test. Yields of winterized oil from soybean oil hydrogenated to several linolenate levels were therefore studied. Partially hydrogenated soybean oil was sampled and filtered at intervals during hydrogenation on a pilot plant scale with a commercial copper-chromite catalyst. Samples were then vacuum bleached and filtered to remove dissolved copper, held at 7 C for 48 hr and filtered to remove stearines. The filtered winter oils passed the standard 5.5 hr cold test. For soybean oil in which linolenate was reduced to 0.1% with a commercial copper-chromite catalyst or to 3.0% with a nickel catalyst yields of winter oil were about the same; 92% for a 5.5 hr cold test oil (winterized two days at 7 C) and 89% for a 20 hr cold test oil (winterized two days at 4 C).