| Summary: | 碩士 === 靜宜大學 === 應用化學研究所 === 96 === ABSTRACT
Gasoline mixtures containing oxygenated compounds, such as ethers and alkanols are increasingly used as additives to gasoline owing to their octane-enhancing and pollution-reducing properties. In this study, vapor-liquid equilibria were measured by mixing the fuel oxygenates that might be used as an octane enhancer with one of the gasoline components. The fuel oxygenates considered are 1,3-dioxolane and 2-propanol, and the component in gasoline is 2,2,4-trimethylpentane. In this work, we measure the vapor liquid equilibrium at 101.3 kPa for three binary systems and one ternary system of 1,3-dioxolane +2-propanol +2,2,4-trimethylpentane.
The activity coefficients of liquid mixtures were calculated by both the equation with fugacity coefficients and the equation based on the modified Raoult’s law. We calculated the vapor-phase fugacity coefficients by Soave-Relich-Kwong equation of state. 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. For thermodyna-
mic consistency, binary systems were tested by the Kojima method and the direct test by Van Ness. The thermodynamic consistency of the ternary data was tested by the McDermott-Ellis method modified by Wisniak and Tamir.
In the treatment of experimental date, the liquid activity coefficients were correlated using the Margules, Van Laar, Wilson, NRTL and UNIQUAC models. The models with the best-fitted parameters were used to predict the ternary VLE data. The excess molar Gibbs free energy, equilibrium boiling temperature of binary systems were correlated with the Redlich-Kister equation. For the ternary system, we used the equations from Jasinski and Malanowskiz, Cibulka, Singh, Pintos, Calvo, Mascato and the other equations to correlate the excess molar Gibbs free energy and equilibrium boiling temperature data.
|
|---|
