Vapor Liquid Equilibrium For The Binary Systems Of 2,2-dimethylbutane + Alcohols At Normal Pressure

Hexane includes five isomers. The mixture of the hexane isomers is used as an important chemical solvent in many fields. Ethanol and 1-propanol are important reactant. The binary systems 2,2-dimethylbutane + ethanol and 2,2-dimethylbutane + 1-propanol form azeotrope at the atmospheric pressure. And vapor liquid equilibrium data of these binary systems can not be found in the literature. It has an important significance to measure the isobaric vapor liquid equilibrium of two binary systems 2,2-dimethylbutane + ethanol and + 1-propanol at 101.3kPa.A double circulating vapor liquid equilibrium apparatus was designed and established. In order to test the accuracy of apparatus, the binary system ethanol + water at 101.3kPa was measured and the result was compared with the data in the literature. Isobaric vapor liquid equilibrium of two binary systems 2,2-dimethylbutane + ethanol and + 1-propanol at 101.3kPa was measured. The experimental data passed thermodynamic consistent test. Both of the systems measured exhibited posit ive deviation from Raoult's law. The azeotropic behaviour was observed. NRTL equation was used to correlate the vapor liquid equilibrium data of the binary systems to obtain the model parameters by Aspen Plus software. With the parameters, vapor composition was calculated and compared with the corresponding experimental data. The average deviations between calculated and experimental vapor composition were less than 0.02. The result showed that NRTL model was applicable for these two binary systems.The predictions to data of vapor liquid equilibrium for two binary systems 2,2-dimethylbutane + ethanol and + 1-propanol at 101.3kPa were performed by the UNIFAC model. Then the predicted results were compared with the experimental data. The result showed that the predicted and the experimental data had good agreement except of the data near the azeotropic point.