Phase Equilibrium Behavior for Fatty Ester Hydrogenolysis Components: L1L2V Equilibria and Retrograde Condensation

L.J. ROVETTO; C.J. PETERS; E.A. BRIGNOLE

Florianopolis, Brazil

Congreso; V Encontro Brasileiro de Fluidos Supercríticos; 2004

Fatty alcohols (FOH) are mostly used in lubricant and surfactant industry. The traditional process to obtain FOH is by heterogeneous catalytic hydrogenolysis, at high pressure, of the corresponding fatty acids methyl esters (FAME). The low solubility of hydrogen into the liquid phase leads to low concentration at the catalyst surface and very low reaction rates. Using a supercritical solvent it is possible to bring the whole reaction mixture into a homogeneous single phase. In this way the concentration of the reactants and the operation variables can be independently controlled, the solubility and mass transfer limitations are removed, giving a dramatic increase in the reaction rate. Knowledge of the reaction mixture phase equilibria, and the boundaries of the homogeneous phase region is required in order to determine the most favorable operating conditions for supercritical hydrogenolysis. In the present work, the phase behavior of binary and ternary mixtures with methyl palmitate, hexadecanol, methanol, hydrogen and propane are presented. The range of temperatures covered was between 300K and 450K and of pressures up to 16 MPa. Liquid-liquid-vapor equilibria was found for the system hydrogen + propane + hexadecanol, with retrograde condensation of the lighter liquid.