The problems of low reaction rate and cis-trans isomerization encountered in the gas-liquid catalyzed hydrogenation of vegetable oils can be overcome by using a supercritical fluid to bring the reactive mixture into a homogeneous phase. For that purpose, experimental phase equilibrium data on mixtures of high molecular weight substrates with hydrogen and a supercritical fluid are needed in order to evaluate optimum process conditions. In this work vapor-liquid and liquid-liquid equilibria in mixtures of hydrogen +propane+tripalmitin have been measured. A temperature region between 323 and 453 K, and pressures up to 15 MPa were covered. (C) 2002 Elsevier Science B.V. All rights reserved.