Study On Separation Of Acetonitrile And Ethyl Acetate Mixture By Batch Zeotropic Distillation

Acetonitrile(AN) and ethyl acetate(EA) are the excellent organic solvents and chemical raw materials, which are frequently used in chemical industry and pharmaceutical process. The mixture of them is hard to be separated with conventional distillation and is hard to be recycled, for the fact that it has a relative volatility approaching 1, an azeotropic system. Right now, there is little literature about the separation of AN and EA.In this paper, the experiment about separation of AN and EA was mainly studied with heterogeneous batch azeotropic distillation(HBAD). First of all, the study of entrainer selection was performed and the n-hexane was finally selected as entrainer for the separation. By the experiment of Vapor-liquid phase equilibrium of AN,EA and n-hexane,testified that n-hexane is feasible as the entrainer . Second, the Liquid-liquid phase equilibrium of AN and n-hexane was studied completely. Third, with the entrainer, the separation experiment of AN and EA was carried out on HBAD. The result showed that n-hexane could successfully serve as the entrainer for such mixture separation process.Finally, a new model was set up for mathematical simulation, in which reboiler, trays, condenser, decanter were composed the whole distillation tower. Due to the non-ideal behavior, UNIFAC model was used to calculate vapor-liquid and liquid-liquid equilibrium of the system. The Newton-Raphson's method and connotation of two points bubble method were combined for the calculation of the tower. Based on comparison of the result of heterogeneous distillation operation experiment with that of the process simulation, it can be found that the model was accurate and reliable for the simulation of batch heterogeneous distillation.