Determination and Modeling of Solid–Liquid Equilibrium for the Ternary System of l-Pyroglutamic Acid + l-Glutamic Acid + Water at T = 298.15–328.15 K

Abstract

The solid-liquid phase equilibrium for the ternary system of L-Pyroglutamic acid + L-Glutamic acid + water was determined experimentally by the isothermal solution saturation method at temperatures of 298.15, 308.15, 318.15, and 328.15K under normal atmosphere. According to the obtained solubility data, four ternary phase diagrams and the variable-temperature phase diagram were constructed. Two pure solids, pure L-Pyroglutamic acid and pure L-Glutamic acid, were generated in the L-Pyroglutamic acid + L-Glutamic acid + water system. In the phase diagrams, there were in all three crystallization zones, two cosaturated solubility curves, and one cosaturated point. The variable-temperature phase diagram for the ternary system of L-Pyroglutamic acid + L-Glutamic acid + water could be used for separation and purification L-Pyroglutamic acid and L-Glutamic acid from its mixture. The data of solid-liquid phase equilibrium were correlated and computed with the NRTL model and Wilson model. The RMSD (root mean squar...