Study On Liquid-Liquid Equilibrium Of Ternary Systems Containing N-Butyl Acetate,Ethyl Butyrate And N-Pentyl Acetate

n-Propanol and 2-propanol,important chemical raw materials,are widely used in medicine,cosmetics,spices,coatings and other fields.So the purity of n-propanol and 2-propanol is more demanding in chemical production.However,n-propanol and 2-propanol can form minimum azeotrope with water,which causes the separation of n-propanol and 2-propanol from the aqueous solutions more difficult by traditional distillation method.Liquid-liquid extraction is a new and efficient technique to separate alcohol-water azeotrope.And the key of this separation technique is to select the right extraction agents.n-Butyl acetate,ethyl butyrate and n-pentyl acetate,having low vapour pressure,low water solubility and toxicity,are potential traditional organic extraction agents.For liquid-liquid extraction technology,reliable liquid-liquid equilibrium(LLE)data are beneficial to select extraction agents and understand the thermodynamic behavior of multicomponent systems.In this work,the LLE data for binary systems(water + n-butyl acetate/ethyl butyrate/n-pentyl acetate),the ternary systems(water + n-propanol + n-butyl acetate/ethyl butyrate/n-pentyl acetate)and the ternary systems(water + 2-propanol + ethyl butyrate/n-pentyl acetate)were determined at T =(293.15,303.15,313.15)K and p = 100 k Pa.The distribution coefficients and separation factors were applied to evaluate extracting capability of the three esters to extract n-propanol and 2-propanol from aqueous solutions.The distribution coefficients and separation factors of the ternary systems(water + n-propanol + n-butyl acetate/ethyl butyrate/n-pentyl acetate)were(4.57-11.19)and(15.17-104.21),respectively,while those of the ternary systems(water + 2-propanol + ethyl butyrate/n-pentyl acetate)were(2.45-6.39)and(10.83-70.16),respectively.The high separation factors indicate the three esters are efficient extraction agents for the extraction of n-propanol and 2-propanol from aqueous solutions.The thermodynamic modified and extended UNIQUAC models were used to correlate the experimental values of the five ternary systems,with average root-mean-square deviations of 0.59 mol% and 0.92 mol%,respectively.It shows the difference between the measured values and the calculation values of the two models is very small,and the measured LLE data can be successfully correlated by two models.The reliability of the experimental data was confirmed by using Othmer-Tobias,Hand and Bachman equations.The average values of the correlation factors were greater than 0.96,which proves high reliability and a good linear relation of the experimental data.