Study On Liquid-liquid Equilibria For Water-methanol-methyl Anthrani1ate-toluene And Its Constituent Systems

Methyl anthrani1ate (MA) is an important industrial material. The preparation of MA brings about a large quantity of waste water, including approximately 5% methanol and 3‰MA. Because of the expensive price of MA, the recovery of MA can not improve economic returns, but also will be valuable in environment protection.In this work, toluene was chosen to extract MA. The separating process of extraction is based on Liquid-Liquid Equilibria. In this paper, LLE data for two binary systems(water-MA and water-toluene), three ternary systems(water-toluene-MA, water-methanol-MA and water-methanol-toluene) and one quaternary system(water-methanol-toluene-MA) was measured at atmospheric pressure and T=(298.15, 313.15 and 323.15) K by equilibrium still. The LLE experimental data were correlated using UNIQUAC and NRTL models.The binary interaction parameter of water-MA was obtained by regressing LLE data of water-MA. The binary interaction parameter of toluene-MA was obtained by regressing LLE data of the ternary system water-toluene-MA with the binary interaction parameters of water-MA and water-toluene. The binary interaction parameter of methanol-MA was obtained by regressing LLE data of the ternary system water-methanol-MA with the binary interaction parameters of water-MA and water-methanol. The binary interaction parameter of methanol-toluene was obtained by regressing LLE data of the ternary system water-methanol-toluene with the binary interaction parameter of water-toluene and water-methanol. The correlated results were in agreement with the results of the experiment, but the correlation accuracy of NRTL model was inferior to that of UNIQUAC model.These binary interaction parameters were used to predict LLE data of the quaternary system water-methanol-toluene-MA at atmospheric pressure and T= (298.15, 313.15 and 323.15) K. And the predicted values were in agreement with the experiment values, but the predicted accuracy of UNIQUAC model was better to that of NRTL model. Finally, the UNIQUAC model and these multibody interaction parameters can be applied to the recovery of MA in the separation proeess.