Vapor–Liquid Equilibria Measurements for the Five Linear C₆ Esters with n-Octane

Abstract

Vapor–liquid equilibrium (VLE) data were measured for the five binary systems comprising each of the unbranched constitutional isomers of a C6 ester with n-octane at 60.0 kPa. All five systems exhibited strong positive deviations from ideality and minimum boiling azeotropes due to the fundamental differences in the intermolecular forces of each component in the pair, as well as the closeness of the pure component boiling points at the system pressure. Thermodynamic consistency of all data was shown using the Wisniak L/W and McDermott–Ellis consistency tests, and the data were correlated and predicted with the NRTL and UNIFAC activity coefficient models, respectively. The data illustrated the role of the location of the polar ester functional group on the phase behavior of respective ester structural isomers with a common second component.

Expanding SAFT-γ Mie’s Application to Dipolar Species: 2-Ketones, 3-Ketones, and Propanoate Esters

“…This Results section primarily features low-pressure mixture predictions because the modeling of these systems forms an initial step in evaluating the newly generated groups. The integrity of new group-specific parameters and interaction parameters and the reliability of the pseudo-association approach are important to consider for pure-component 48 and n-nonane + 3-heptanone at 0.400 bar (△) 48 and (b) noctane + n-butyl ethanoate at 0.600 bar ( ◇ ) 50 and n-octane + propyl propanoate at 0.600 bar (△). 50 Figure 5.…”

“…The integrity of new group-specific parameters and interaction parameters and the reliability of the pseudo-association approach are important to consider for pure-component 48 and n-nonane + 3-heptanone at 0.400 bar (△) 48 and (b) noctane + n-butyl ethanoate at 0.600 bar ( ◇ ) 50 and n-octane + propyl propanoate at 0.600 bar (△). 50 Figure 5. Liquid-phase property predictions with SAFT-γ Mie (solid blue lines) of binary systems at 298.15 K and 1.013 bar, each containing a newly parametrized group: (a) excess enthalpy of n-heptane + 2butanone ( ◇ ), 47 n-heptane + 3-pentanone (△), 47 and n-heptane + propyl propanoate ( □ ) 60 and (b) speed of sound of n-heptane + 2butanone ( ◇ ) 61 and n-heptane + 3-pentanone (△).…”

Vapor–Liquid Equilibria Measurements for Di-n-Propyl Ether and Butyl Ethyl Ether with n-Heptane

“…The equilibrium temperature was measured with a 4-wire Pt-100 probe connected to a digital Hart Scientific Thermometer, with a calibrated uncertainty of 0.1 K between 313 and 413 K. The calibration was performed by a SANAS (South African National Accreditation System) approved laboratory, adhering to international calibration standards. The unit is the same as that used in our previous works and the reader is directed to the paper dealing with the ester/nalkane systems 20 for a detailed account of the experimental procedure. Duplicate analytical samples were prepared from each equilibrium phase using 2-ethyl-1-hexanol as a solvent.…”

“…In two previous works, a more systematic approach was taken in the generation of new phase equilibrium data for binary systems of hydrocarbons with medium length linear ketones and esters . There, VLE data for different structural isomers of the polar molecule coupled with the same n -alkane were generated and, in this way, the effect of the polar functional group location on phase behavior of the different isomers could be investigated.…”

“…In two previous works, a more systematic approach was taken in the generation of new phase equilibrium data for binary systems of hydrocarbons with medium length linear ketones 19 and esters. 20 There, VLE data for different structural isomers of the polar molecule coupled with the same n-alkane were generated and, in this way, the effect of the polar functional group location on phase behavior of the different isomers could be investigated. The rationale for this theoretical approach is to use the systematically measured phase equilibrium data, previously unavailable in the literature, as a test for the analytical capacity of predictive thermodynamic models.…”