Edible oil hydrogenation rates in the presence of a homogeneous Ziegler—Natta catalyst in a film reactor

Abstract

The rates of edible oil hydrogenation in the presence of a homogeneous Ziegler—Natta catalyst has been measured in a falling-film reactor with a view to the ultimate determination of the hydrogen/edible oil interfacial area in an agitated tank under a fast reaction regime. The catalyst is a combination of nickel diisopropyl salicylate (Ni(dips) 2) and aluminium triisobutyl (Al( iBu) 3). The reaction rates have been determined by measuring hydrogen absorption rates into soyabean and safflower oils under a fast reaction regime (Ha > 3). The gas absorption has been measured as a function of pressure, temperature, catalyst concentration, molar ratio (α) of Al( iBu) 3 to Ni(dips) 2 and concentration of unsaturated triglycerides in the oils (iodine value, I.V.). The hydrogenation rates can be described by R 2 = K nc 1.7 for 50 < I.V. < 130 and R 1 = Kc 1.7 b 0.55 for 5 < I.V. < 50 ( c = concentration of hydrogen in oil, b = concentration of unsaturated triglycerides in oil), under the conditions 5×10 4< P/(Pa)<1.4×10 5, 55 < T/(°C)<95, 1.5×10 −3<Ni(dips) 2/(kmol·m −3)<2.75x10 −2 and 4<α<10.