Experimental and modeling insights into excess molar enthalpy of alcohol–additive ternary mixtures at 298.15 and 313.15 K

Abstract

The increasing demand for cleaner energy carriers has intensified interest in liquid fuel blends containing oxygenated compounds such as alcohols and glycol ethers. These additives improve combustion efficiency and reduce environmental impact. In this work, excess molar enthalpies were determined for a binary mixtures (ethanol + 1-propanol; diethylene glycol monoethyl ether + 1-propanol; and ethylene glycol monophenyl ether + ethanol) as well as for four ternary mixtures: diethylene glycol monomethyl ether (1) + 1-propanol (2) + ethanol (3), diethylene glycol monoethyl ether (1) + 1-propanol (2) + ethanol (3), ethylene glycol monomethyl ether (1) + 1-propanol (2) + ethanol (3), and ethylene glycol monophenyl ether (1) + 1-propanol (2) + ethanol (3). Measurements were obtained with a quasi-isothermal flow calorimeter at 298.15 K and 313.15 K under 0.1 MPa, conditions representative of typical industrial applications. The experimental data were then correlated using the Redlich–Kister equation for the binary system and the NRTL, UNIQUAC, and modified UNIFAC (Dortmund) models for the ternary systems, enabling evaluation of both mixture behavior and model accuracy. The findings expand the thermodynamic database for alcohol- and glycol ether-based blends and provide benchmarks for simulation and design in energy and petrochemical processes.