Solid–Liquid Equilibrium of 2,4,6-Trinitrotoluene in Ethanol + Water Binary Mixed Solvent: Experiments, Correlation, Thermodynamic Analysis

The solubility of 2,4,6-trinitrotoluene in ethanol + water mixed solvents was systematically determined using the gravimetric method within the temperature range from 298.15 K to 338.15 K and under a pressure of 0.1 MPa. The experimental results indicate that in this binary solvent system, the solubility of 2,4,6-trinitrotoluene increases monotonically with the rise in the molar fraction of ethanol. Furthermore, over the investigated temperature range, the solubility also increases with temperature. To enhance the applicability of the solubility data, the experimental results were correlated using four thermodynamic models: the modified Apelblat model, the van’t Hoff model, the Yaws model, and the CNIBS/R–K model. The correlation performance of each model was evaluated based on relative deviation, average relative deviation, and root mean square deviation. The results demonstrate that all models exhibit satisfactory correlation accuracy in the selected solvent system, with the CNIBS/R–K model showing the best performance. This study provides important fundamental data for the optimization of the synthesis process of 2,2′4,4′6,6′-hexanitrostilbene.