LLE for the systems ethyl palmitate (palmitic acid)(1) + ethanol(2) + glycerol (water)(3)

• We measured LLE for the ethanol-based biodiesel systems. Ethyl palmitate + ethanol + glycerol (or water) were measured.
• Palmitic acid + ethanol + water were also measured.
• Tie lines and binodal curves were measured for all systems.
• The experimental data were modeled using NRTL, UNIQUAC and UNIFAC models.

This work reports a new experimental set of liquid–liquid equilibrium measurements for the systems ethyl palmitate(1) + ethanol(2) + glycerol(3) and ethyl palmitate(1) + ethanol(2) + water(3) at atmospheric pressure and at 298.15 K and 313.15, and for the system palmitic acid(1) + ethanol(2) + water(3) at 338.15 K. The liquid-phases compositions were measured by determining their refractive index and densities. Solubility curves (binodal) were also obtained by cloud-point method for ternary systems. The experimental data were satisfactorily correlated by NRTL and UNIQUAC equations. A comparative analysis was performed using the UNIFAC-LL and UNIFAC-Dortmund group contribution method. Interesting results from thermodynamics models were obtained for the systems studied in this work.