Sunflower oil was hydrogenated in a stirred-batch unit, using supercritical and near-critical propane as solvent, and Pd/gamma-Al2O3 catalyst. The effect of the phase behavior on the reaction performance is analyzed. The transition from homogeneous to heterogeneous conditions showed no effect on the activity and selectivity of the reaction. These results point to an unrestricted availability of hydrogen at the catalyst surface. A comparison is made between fluid-solid mass transfer coefficients in stirred-batch and continuous fixed-bed reactors. (C) 2009 Elsevier B.V. All rights reserved.