| Titre : | Thermodynamics of hydrogen-bonding mixtures. 5. GE, HE, and TSE and zeotropy of water + acrylic acid (2008) |
| Auteurs : | James D. Olson, Auteur ; Richard E. Morrison, Auteur ; Loren C. Wilson, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | Industrial & engineering chemistry research (Vol. 47 n°15, Août 2008) |
| Article en page(s) : | p. 5127–5131 |
| Note générale : | Bibliogr. p. 5131 |
| Langues : | Anglais |
| Tags : | Stirred-flask ebulliometer -- vapor-pressure ; Zeotrope ; Vapor—liquid equilibrium |
| Résumé : | A stirred-flask ebulliometer was used to measure total vapor-pressure (PTx) data on nine mixtures of water + acrylic acid (and the pure components) between 45 and 112 °C and pressures from 10.00 to 101.325 kPa. These PTx data and the derived vapor—liquid equilibrium data show no azeotropic behavior. To verify that water + acrylic acid is a zeotrope at 101.325 kPa, dilute-solution ΔT data at 101.325 kPa were measured in a twin-arm Cottrell-lift-pump ebulliometer. Data on water + propanoic acid, with a known azeotrope at 101.325 kPa, were measured to test the experimental method. These dilute-solution measurements confirmed the known azeotrope for water + propanoic acid and conclusively demonstrated zeotropy for water + acrylic acid at 101.325 kPa. The system exhibits large positive deviations from ideality (derived γ∞ = 2.5−5.7) that decrease with increasing temperature. Equimolar GE/T derived from fitted isothermal activity coefficient parameters decreases with increasing temperature, which predicts a positive HE. The excess function data show that the system water + acrylic acid belongs to the class of mixtures where GE > 0 and HE > 0 (this includes other water + organic acid mixtures); TSE shows a crossover from TSE > 0 to TSE < 0. |
| En ligne : | http://pubs.acs.org/doi/abs/10.1021/ie0712277 |
