Revisiting the hydrogenation of sunflower oil over a Ni catalyst

In the present paper the performance of commercial Ni catalyst in edible oil hydrogenation is evaluated under different operating conditions. Particularly, the influence of mass transport resistance on the trans-isomers selectivity is analyzed. Initially a series of experiments aim to analyze the effect of four process variables (reaction temperature, hydrogen bubbling device, agitation rate and stirrer design) on catalyst activity and selectivity to trans-isomers. These experiments are conducted in diffusional regimes. A simpler set of experiments is carried out operating under conditions that allow the authors to neglect some diffusional resistances although those associated to the catalyst are still present. In the first case activity and selectivity appear to be independent of the hydrogen bubbling system and the catalyst loading. The whole set of data analyzed in terms of the C18:1/C18:20 ratio as a function of the C18:2/C18:20 ratio shows that the former, a sort of selectivity, depends on the agitation regime. The formation of trans-isomers however, appears to be a function of the reaction extent only.