Article pubs.acs.org/jced
Cite This: J. Chem. Eng. Data XXXX, XXX, XXX−XXX
Experimental Determination of Isobaric Vapor−Liquid Equilibrium and Isothermal Interfacial Tensions for the Binary Ethanol + Cyclopentyl Methyl Ether Mixture Andrés Mejía* and Marcela Cartes
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Departamento de Ingeniería Química, Universidad de Concepción P.O.B. 160−C, Correo 3, Concepción, Chile ABSTRACT: This work describes the vapor−liquid equilibrium (VLE) data experimentally measured at three isobaric conditions 50, 75, and 94 kPa and over the temperature range from 334 to 375 K and the atmospheric interfacial tensions (IFT) measured at the isothermal of 298.15 K in the whole mole fraction range for the ethanol + cyclopentyl methyl ether binary system. In order to carry out the experimental determinations, a dynamic all-glass Guillespie type cell was used to carry out VLE measurements, whereas a maximum differential bubble pressure tensiometer was used to IFT determinations. Because few experimental data are available for cyclopentyl methyl ether, vapor pressures and interfacial tensions have also been measured over the temperature range 341−378 K and 298−353 K, respectively. According to the experimental results, the binary system ethanol + cyclopentyl methyl ether displays a positive deviation from the Raoult’s law with a minimum temperature azeotropic over the whole explored pressure range. The azeotropic mole fraction increases in ethanol as pressure and/or temperature increases. For the case of interfacial tensions, they display positive deviation from the linear behavior. The measured VLE data of the ethanol + cyclopentyl methyl ether mixture are thermodynamically consistent as stated by the Fredenlund’s test. Additionally, the VLE were well-correlated by classical activity coefficients models (e.g., Wohl, NRTL, Wilson, and UNIQUAC) for all of the measured isobar conditions. The measured interfacial tensions of the mixture were satisfactorily correlated by the Myers−Scott equation.
1. INTRODUCTION Oxygenate fuels, a mixture of petroleum (fossil) fuel and oxygenate additives, have been incorporated in the fuel market in the 1990s not only to replace the alkyl-lead and other metalcontaining additives but also to increase the oxygen content in fuel blends. The high oxygen content reduces the fraction of unburned hydrocarbons released to the atmosphere that are widely acknowledged to be a major contributor to global warming. Fuel mixed with oxygenate additives (that is, oxygenated gasoline) usually contains a small portion of oxygen (
