Separation Of Isopropyl Alcohol And Isopropyl Acetate By Extractive Distillation

Isopropyl alcohol and isopropyl acetate,which have very important application value in the fields of chemistry,chemical engineering,medicine,etc,are often required to separation and purification in the process industry.Due to the formation of the minimum azeotrope,the binary mixture cannot be separated by a simple distillation.Extractive distillation,a special rectification process,is widely used in the separation of azeotropic systems.The main purpose of this paper is to simulate and optimize the seperation process of the isopropyl alcohol and isopropyl acetate by extractive distillation.The vapor-liquid equilibria for ternary mixtures of isopropyl alcohol,isopropyl acetate and extraction agent were studied.The obtained binary interaction parameters were used to simulate axtractive distillation process,in order to reduce the costs and improve the purity of the product.The simulation of extractive distillation provides a theoretical guidance to separate the isopropyl alcohol and isopropyl acetate in process industry.DMSO(dimethyl sulfoxide),a general solvent,was often used as extraction agent to separate the alcohols and esters.Ionic liquid used as extractive distillation to separate the azeotrope system has also been widespread concerned.Therefore,DMSO and ionic liquid [EMIM][BF4](1-ethyl-3-methylimidazolium tetrafluoroborate)were select as the extraction agent to separate the isopropyl alcohol and isopropyl acetate by extractive distillation.Firstly,the vapor-liquid equilibrium(VLE)data for the binary system isopropyl alcohol + DMSO,isopropyl acetate + DMSO and ternary system isopropyl alcohol + isopropyl acetate + DMSO were measured with a VLE modified Othmer still at 101.3 kPa.The experimental data were proved to be thermodynamically consistent when the Herington area test and Van Ness test was applied.The binary experimental data were correlated by the Aspen Plus software.Then,the ternary VLE data were predicted with the obtained binary interaction parameters.When the mole ratio of the binary azeotrope to DMSO was 1:1.5,the binary azeotrope of isopropyl alcohol and isopropyl acetate was eliminated.Secondly,the VLE data for the ternary system of isopropyl alcohol + isopropyl acetate + [EMIM][BF4] were measured.When the mole fraction of [EMIM][BF4] was 10%,the binary azeotrope of isopropyl alcohol and isopropyl acetate was eliminated.Therefore,DMSO and [EMIM][BF4] are potential extractive agent to separate the binary azeotrope by extractive distillation.Eventually,the extractive distillation of the ternary system was simulated using obtained binary interaction parameters with the process simulation software Aspen Plus.The separation conditions of isopropyl alcohol and isopropyl acetate with different operational parameters(stage number,feed stage,solvent ratio and reflux ratio)were discussed and the optimum conditions were achieved: Number of trays was 60,the material feed tray was 32,the solvent feed tray was 6,the reflux ratio was 2.1 and the solvent ratio was 2.33.the mole fraction of the isopropyl acetate and isopropyl alcohol was 99.6% and 99.0% respectively in this operating condition.These operating parameters can provide a theoretical guidance for the industrial separation of isopropyl alcohol and isopropyl acetate.