Dimethyl Isosorbide and Its Mixtures with Aliphatic/Aromatic Hydrocarbons: Binary and Ternary Liquid–Liquid Equilibria and Thermodynamic Characterization

This study examines the thermodynamic and physicochemical properties of dimethyl isosorbide (DMI), a novel green solvent, in its pure form and in binary and ternary mixtures with aliphatic and aromatic hydrocarbons. In this paper, we present the systematic measurements of DMI’s density and dynamic viscosity over a temperature range of 288.15–343.15 K at pressure p = 100 kPa. The results show that DMI exhibits moderate density and viscosity compared to other green solvents. Furthermore, liquid–liquid equilibrium (LLE) data were obtained for three binary systems comprising aliphatic hydrocarbons (DMI + (n-hexane, n-decane, and n-tetradecane)) and two ternary systems (n-hexane + (benzene or toluene) + DMI). The behavior of these mixtures was described using the extended scaling law (ESL) and the NRTL equations, with both models providing accurate descriptions. The biphasic regions of the binary systems were notably smaller than those observed in other green solvent-containing systems. The ternary systems exhibited type I behavior according to Treybal classification. The extraction efficiency analysis revealed that the use of DMI might not be advantageous for the aromatic/aliphatic separation. Despite this fact, the obtained thermodynamic description of the DMI’s behavior could contribute to the future design of sustainable processes.