0000000000021702
AUTHOR
Hugo Segura
Isobaric vapor-liquid equilibria and densities for the system methyl 1,1-dimethylethyl ether+2-propanol
Vapor-liquid equilibrium data at 50, 75 and 94 kPa have been determined for the binary system methyl 1,1-dimethylethyl ether + 2-propanol, in the temperature range 308-344 K. The measurements were made in an equilibrium still with circulation of both the vapor and liquid phases. Excess volumes have been also determined from density measurements using a vibrating tube densimeter at 298.15 K. The system exhibits positive deviation from ideal behavior and does not present azeotropy within the range of pressures studied. The excess volume of the system is negative over the whole mole fraction range. The activity coefficients and boiling points of the solutions were well correlated with the mole…
Phase equilibria and multiple azeotropy in the associating system methanol + diethylamine
Vapor−liquid equilibrium has been measured for the binary system of methanol (1) + diethylamine (2) at 101.3 and 300 kPa. Both equilibrium isobars show strong deviations from ideal behavior and a single maximum boiling point azeotrope of practically constant composition x1 ≈ 0.76, corresponding to a temperature of 339.8 K at 101.3 kPa and 370.0 K at 300 kPa. The trend of the high-pressure isobar data is consistent with the formation of a second minimum boiling azeotrope, confirming the multiple azeotropic behavior found by others at a higher temperature (398.58 K). Furthermore, the excess Gibbs energy is negative and inflects markedly with composition with increased pressure. The equilibriu…
Nonazeotropy in the System Methyl Ethanoate + 1,2-Epoxybutane
New vapor−liquid equilibrium data for the binary system methyl ethanoate + 1,2-epoxybutane are reported at 35 and 101.3 kPa and at 298.15 K. It is shown that no azeotropes are present in the system, in disagreement with data reported by others who claim that two azeotropes are present at 298.15 K. We claim that previously reported data are in error because of impurities in the reagents and experimental errors. According to our results, the system methyl ethanoate + 1,2-epoxybutane behaves like a regular solution and its vapor phase can be considered practically ideal so that it cannot fulfill the necessary conditions for multiple azeotropy. The data were satisfactorily correlated using the …