Liquid-liquid equilibrium data and thermodynamic modeling, at T/K=298.2, in the washing step of ethyl biodiesel production from crambe, fodder radish and macauba pulp oils

Abstract In this work, pseudo-ternary liquid–liquid equilibrium data were obtained for three systems composed for water + ethanol + ethyl biodiesel from crambe, fodder radish and macauba pulp oils, at T / K  = 298.2. Ethanol, which distributes in both phases, had greater affinity for the water-rich phase. Biodiesels and water showed almost complete immiscibility. Modeling with the NRTL and UNIQUAC thermodynamic models was performed, resulting in average deviations ranging from 0.49% to 1.29%. UNIFAC-LLE and UNIFAC-Dortmund were used in prediction of the liquid–liquid equilibrium of these systems, resulting in average deviations ranging from 1.91% to 2.27% for the systems containing biodiesel from crambe and fodder radish oils, and ranging from 3.17% to 3.28% for biodiesel from macauba oil.