Phase Equilibrium Study Of The Purification Process Of Isopropyl Acetate And 2B Acid

Isopropyl acetate and 4-Amino-2-chlorotoluene-5-sulfonic acid(2B Acid)are important chemical materials and synthesis intermediates.The purity is the most important parameters for characterizing the quality of chemical products.The phase equilibrium data is essential for the selection of the purification process,design of the device and determination of the separation conditions.To improve the production process and purities of isopropyl acetate and 2B acid,it's necessary to obtain their phase equilibrium data.Generally,isopropyl acetate was produced from the esterification of acetic acid and 2-propanol.Isopropyl acetate and the residual 2-propanol form an azeotropic mixture in this process,which is difficult to be separated by the traditional distillation.In this paper,glycerin was used as extraction agents to separate this azeotrope.The liquid-liquid equilibrium(LLE)data of isopropyl acetate + 2-propanol + glycerol were measured at various temperatures T=(298.15,308.15,318.15)K.The validation of the experimental data was verified and it shows good consistency.The system was a type-I system and temperature has little effect on its phase equilibrium.Glycerin displayed very high selectivity during the extraction process.The NRTL and the UNIQUAC models were applied to correlate the experimental data and low deviations were obtained.2B acid is an important organic pigment intermediate.China has the largest production capacity of 2B in the world.But inadequate product purity.is a main reason which limit its export.The solid-liquid equilibrium(SLE)data is essential for the purification of solid chemicals.However,no SLE data of 2B acid has been found in any open literatures.In this paper,the solubility of 2B acid in the binary solvent of ethanol + water,acetone + water,acetonitrile + water as well as the solubility in pure water was measured at the temperature range of 275 K~ 340 K.The experimental results show that the solubility of 2B acid increases with the temperature.The SLE data of the three systems all displayed significant synergistic effect that the solubility of 2B acid is lager in the binary solvent mixtures than any of the pure solvent.The SLE data was correlated by Apelblat and Van't Hoff equations and both of them can match the experimental data very well.