Hydrogenation of sunflower oil on Pd catalysts in supercritical conditions: Effect of the particle size

The sunflower oil hydrogenation at conventional conditions is insensitive to the catalyst surface morphology, mostly because the reaction is diffusion controlled. The addition of a supercritical solvent permits the hydrogenation reaction to occur in a homogeneous phase in contact with the solid catalyst.Activity and selectivity were analyzed using supercritical propane and γ-Al2O3 supported Pd catalysts with different particle size. No significant variations were observed in the reaction rate. On the other hand, cis-isomers selectivity and the production of saturated compound were favored in the case of the smallest metallic particle size (<2 nm).Despite that during the reaction there occurred a phase separation, propane was in supercritical state in both phases. Thus, the advantages mentioned regarding mass transfer could still be observed.