Vapor-Liquid Equilibria for Mixtures of Ethanol, 2-Butanone, and 2,2,4-Trimethylpentane

• Main Authors: Chao-Cheng Wen, 溫兆呈
• Other Authors: Chein-Hsoun Tu
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/16109537247793011787

碩士 === 靜宜大學 === 應用化學研究所 === 93 === Phase equilibrium is an essential element for developing and designing chemical process as well as enhancing our realization in fluid-pahse behaviors. In general, to add the fuel oxygenates such as ethers and alcohols can enhance octane capability and decrease pollutions. In this study, vapor-liquid equilibria were measured by mixing the fuel oxygenates that might be as an octane enhancer with one of the gasoline components. Such data can provide what the effects in the total vapor pressure of the gasoline and its composition when added the additives. The fuel oxygenates considered are ethanol and 2-butanone, and the component in gasoline is 2,2,4-trimethylpentane. In this study, we measured the vapor-liquid equilibrium (VLE) at 101.3 kPa for the ternary system of ethanol + 2-butanone + isooctane and these of their constituent binaries. In this study, we used Hunsmann’s apparatus to measure VLE, and determined the composition of these systems by gas chromatography method. We also calculated vapor-phase fugacity coefficients by SRK equation. Analysis of the experimental VLE data, all of the binary systems exhibited a minimum boiling temperature. Azeotropic behavior was not found in the ternary system. The experimental data of these binary systems passed the thermodynamic consistency test based on the method of Kojima et al. The data of ternary system also passed the consistency test by a modified McDermott-Ellis method. In the treatment of experimental data, binary systems were correlated with the mole fraction using the Wilson, NRTL, and UNIQUAC models. The models with their best-fitted parameters were used to predict the ternary vapor-liquid equilibrium. The excess molar Gibbs free energy, equilibrium boiling temperature, and vapor-phase composition of all binary systems were correlated with the Redlich-Kister type equation. We used Jasinski and Malanowski equation, Cibulka equation, Sing equation, Pintos equation, Calvo equation, and other extended equations to correlate the equilibrium boiling temperature and excess Gibbs free energy of the ternary system too.