Liquid–liquid equilibria for multicomponent mixtures of 2,2-dimethyl-1,3-dioxolane with n-heptane, toluene, ethanol and water

Liquid–liquid equilibria (LLE) data are presented for two quaternary systems: 2,2-dimethyl-1,3-dioxolane (DMD) + n-heptane (or toluene) + ethanol + water, – and for three ternary subsystems: DMD + ethanol + water and DMD + n-heptane (or toluene) + water. The measurements were performed at 293.15 K and atmospheric pressure. The phase diagrams show extended heterogeneous areas for ternary systems containing n-heptane (or toluene) and water, the region going from water–hydrocarbon side of the concentration triangle to water–DMD side. A much smaller region of immiscibility with the critical point is observed for ternary mixtures of DMD with water and ethanol. The experimental LLE data were correlated and partly predicted applying the NRTL model. The UNIFAC interaction parameters for CH2O groups of dioxolane alkyl-derivatives were estimated. The model was applied to predict the LLE diagrams for ternary DMD + n-heptane (+toluene) + water solutions and for the quaternary systems containing ethanol. Both NRTL and UNIFAC models with re-estimated parameters have provided satisfactory results.