Phase equilibrium behavior for hydrogenolysis components: three-phase equilibria LLV and retrograde behavior

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 drastic increase of the reaction rate. dge of the phase equilibria of the reaction mixture, and the boundaries of the homogeneous phase region are 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, hydrogen and propane is analyzed. The range of temperatures covered was between 300 K and 450 K and of pressures up to 16 MPa. Three-phase liquid–liquid–vapor equilibria were found for the system hydrogen + propane + hexadecanol, with retrograde behavior of the lighter liquid.