Solid-Liquid Phase Equilibria of the Ternary System (2-Naphthaldehyde+4-Methylphthalic Anhydride plus Ethyl Acetate) at (288.15, 298.15, and 308.15) K

The solubility of 2-naphthaldehyde (2-NA) and 4-methylphthalic anhydride (4-MA) in ethyl acetate at temperatures from 283.15 to 313.15 K and solid-liquid equilibrium of ternary (2-NA + 4-MA + ethyl acetate) system at temperatures of (288.15, 298.15, and 308.15) K were measured under pressure of 101.3 kPa. Three isothermal phase diagrams were plotted according to the ternary solubility data. For the ternary system, two pure 2-NA and 4-MA solids were formed at each temperature and determined by the wet residue method of Schreinemaker. The crystalline region of 2-NA decreases with the increase in temperature, and 4-MA is just the opposite. The crystallization region of 2-NA was found to be smaller than that of 4-MA. The solubility data of the system were correlated and calculated by NRTL and Wilson models. The results show that the NRTL model agrees well with the experimental data compared with the Wilson model. Furthermore, the densities of equilibrium solutions were determined at the corresponding temperatures.