HYDROGENATION AT SUPERCRITICAL CONDITIONS OF FATTY ACID METHYL ESTERS: PHASE EQUILIBRIUM MEASUREMENTS ON SELECTED BINARY AND TERNARY SYSTEMS

L.J. ROVETTO; S.B. BOTTINI; E.A. BRIGNOLE; C.J. PETERS

Foz de Iguazu, Brazil

Conferencia; EQUIFASE VI Conferencia Iberoamericana sobre Equilibrio entre Fases para el Diseño de Procesos; 2002

Abstract. Fatty alcohols (FOH) are normally produced by hydrogenolysis of fatty acid methyl esters (FAME), in a catalytic multiphase reaction. The low solubility and mass transport resistance of hydrogen (H2) in the liquid substrate limits the availability of hydrogen at the catalyst surface and causes low reaction rates. Using a supercritical solvent, it is possible to bring the reactive mixture into a single homogeneous phase, which eliminates the mass transport resistance of H2 through the gas-liquid interface. To achieve this goal, propane has been selected as the adequate supercritical solvent. Knowledge of the corresponding phase equilibria is a prerequisite in order to find the homogeneous region and to determine the most favorable conditions for the hydrogenation process. To the best of our knowledge, experimental data on the phase behavior of this system are not available in literature. Therefore, in this study experimental phase equilibrium data of FOH, FAME, H2, and supercritical propane have been determined experimentally. Vapor-liquid equilibrium data of binary mixtures of hydrogen + methyl palmitate and hydrogen + hexadecanol have been measured. In addition, also vapor-liquid equilibrium data have been measured for the following four ternary systems at high propane concentrations: propane + hexadecanol + methyl palmitate, propane + hexadecanol + methanol, hydrogen + propane + methyl palmitate and hydrogen + propane + hexadecanol. A temperature region between 360K and 450K was covered, and pressures up to 15 MPa were applied.