Improving vapour–liquid-equilibria predictions for mixtures with non-associating polar components using sPC-SAFT extended with two dipolar terms

Quantifying the effect of polarity on the behavior of mixtures of n‐alkanes with dipolar solvents using polar soft‐statistical associating fluid theory (Polar soft‐SAFT)

“…Nevertheless, these sets yielded an unphysical liquidliquid demixing region at low dipolar fluid concentration. Such as behavior was also reported for other polar SAFT equations, 27,30,38 when modeling binary mixtures of n-alkanes or n-alkenes with associating dipolar fluids such as alcohols, 37,38 or strong dipolar F I G U R E 6 (a) LLE of acetone with nhexane (□), 77 and n-heptane (Δ), 77,78 (b) VLE of other 2-ketones, 2-butanone and 2-pentanone, with n-hexane (□), 80 and n-heptane (Δ). 81,82 In all cases, calculations from polar soft-SAFT were done in a predictive manner using a transferable ξ = 0.990 (dashed lines) F I G U R E 9 Excess enthalpy of mixtures of, n-pentane (), n-hexane (□), or n-heptane with (a) chloroform, 93 (b) dichloromethane, 93 (c) tetrahydrofuran, 94 (d) acetone, 95,96 and (e) NMP.…”

“…This methodology allows for accurate isolation of polar and dispersive contribution to the overall behavior of pure dipolar fluids, as the effect of similar interactions (i.e., dipolardipolar) will be more dominant on pure fluid properties, while dissimilar interactions (i.e., dispersive-dipolar) will only be manifested in binary mixtures. 12,24,30,35,37 This approach has also been successfully applied in several works 12,30,35,37,38 to the modeling of associating and nonassociating dipolar fluids such as water, alcohols, ketones, aldehydes, and esters, accurately reproducing both their pure behavior and VLE for their mixtures with n-alkanes. However, the efficacy of this approach was not further explored in terms of modeling liquid-liquid equilibria (LLE) of the examined mixtures or modeling strong dipolar fluids (μ > 3.0 D).…”

“…Alternatively, Dominik et al 24 proposed a new parametrization strategy that assists in converging to a unique set of molecular parameters for dipolar fluids, through the inclusion of vapor–liquid equilibria (VLE) data for binary mixtures of dipolar components, with a nonpolar fluid of a similar molecular weight (i.e., n ‐alkane) during parametrization. This methodology allows for accurate isolation of polar and dispersive contribution to the overall behavior of pure dipolar fluids, as the effect of similar interactions (i.e., dipolar–dipolar) will be more dominant on pure fluid properties, while dissimilar interactions (i.e., dispersive–dipolar) will only be manifested in binary mixtures 12,24,30,35,37 . This approach has also been successfully applied in several works 12,30,35,37,38 to the modeling of associating and nonassociating dipolar fluids such as water, alcohols, ketones, aldehydes, and esters, accurately reproducing both their pure behavior and VLE for their mixtures with n ‐alkanes.…”

Vapor Pressures, Densities, and PC-SAFT Parameters for 11 Bio-compounds

“…De Villiers et al [43] showed that it can be difficult to find the best fit for polar compounds using pure component data alone. Often there is a large range of parameter values that will give good results for pure component properties, but poor results for mixtures.…”

Accounting for cross association in non-self-associating species using a physically consistent SAFT-VR Mie approach

“…Unfortunately, such a treatment provided only qualitative predictions of mixture behaviour, particularly in mixtures with non-associating components -a result which contributes to an extensive body of SAFT literature highlighting the need to explicitly account for dipolar interactions [28][29][30][31][32].…”