Vapor-liquid equilibria for methanol + fatty acid methyl ester binary systems near critical temperature of methanol

In biodiesel production processes using supercritical methanol, the phase equilibria for methanol + fatty acid methyl ester systems near the critical temperature of methanol (Tc = 512.6 K) are required as the fundamental data. A flow type method was applied to measure the vapor-liquid equilibria for methanol + fatty acid methyl ester binary systems at 493 – 543 K. The phase behavior was studied by changing the kind of fatty acid methyl esters. The mole fractions of methanol in vapor phase are close to unity for the systems. The present vapor-liquid equilibrium data were correlated by Peng-Robinson Stryjek-Vera equation of state with a modified conventional mixing rule. Inter-molecular parameters in the mixing rule were determined by fitting to the present experimental data obtained in this work. The correlated results are in good agreement with the experimental data.