Thermodynamics of {zNaCl+(1−z)Na2SO4}(aq) from T=278.15K to T=318.15K, and representation with an extended ion-interaction (Pitzer) model

Rard, Joseph A.; Clegg, Simon L.; Platford, R. F.

doi:10.1016/s0021-9614(03)00043-0

Cited by 32 publications

(53 citation statements)

References 44 publications

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“… Osmotic coefficients in mixtures of KCl + NaCl (left) against data from Saad et al and Na 2 SO 4 + NaCl (right) at 25°C, 1 atm against data from Rard et al [Color figure can be viewed in the online issue, which is available at http://wileyonlinelibrary.com. ]…”

Section: The Role Of Solid‐liquid Equilibrium Datamentioning

confidence: 99%

An electrolyte CPA equation of state for mixed solvent electrolytes

2015

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Despite great efforts over the past decades, thermodynamic modeling of electrolytes in mixed solvents is still a challenge today. The existing modeling frameworks based on activity coefficient models are data‐driven and require expert knowledge to be parameterized. It has been suggested that the predictive capabilities could be improved through the development of an electrolyte equation of state. In this work, the Cubic Plus Association (CPA) Equation of State is extended to handle mixtures containing electrolytes by including the electrostatic contributions from the Debye–Hückel and Born terms using a self‐consistent model for the static permittivity. A simple scheme for parameterization of salts with a limited number of parameters is proposed and model parameters for a range of salts are determined from experimental data of activity and osmotic coefficients as well as freezing point depression. Finally, the model is applied to predict VLE, LLE, and SLE in aqueous salt mixtures as well as in mixed solvents. © 2015 American Institute of Chemical Engineers AIChE J, 61: 2933–2950, 2015

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Section: The Role Of Solid‐liquid Equilibrium Datamentioning

confidence: 99%

An electrolyte CPA equation of state for mixed solvent electrolytes

2015

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“…If these higher-order electrostatic effects are neglected, then Table III coefficients [44], and was also used in our earlier work [9,15,18].…”

Section: Extended Ion-interaction Model Equations and Calculations Fomentioning

confidence: 99%

Isopiestic Investigation of the Osmotic and Activity Coefficients of {yMgCl2+(1−y)MgSO4}(aq) and the Osmotic Coefficients of Na2SO4⋅MgSO4(aq) at 298.15 K

et al. 2008

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Isopiestic vapor pressure measurements were made for {yMgCl 2 + (1 -y)MgSO 4 }(aq) solutions with MgCl 2 ionic strength fractions of y = (0, 0.1997, 0.3989, 0.5992, 0.8008, and 1) at the temperature 298.15 K, using KCl(aq) as the reference standard.These measurements for the mixtures cover the ionic strength range I = 0.9794 to 9.4318 mol·kg -1 . In addition, isopiestic measurements were made with NaCl(aq) as reference

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“…Many of these studies used the extended ion-interaction model described by Archer [10,11]. Parameters for the Archer model were subsequently evaluated for Na 2 SO 4 (aq) [15], NdCl 3 (aq) [16], and Mg(NO 3 ) 2 (aq) [17].…”

Section: Introductionmentioning

confidence: 99%

“…15 K, but the solubility increases rapidly with temperature reaching values of m % (22 to 23) mol AE kg À1 for the range T = (328 to 424) K where anhydrous Ca(NO 3 ) 2 (cr) is the thermodynamically stable solid phase [22]. However, as observed by Stokes and Robinson [23] at T = 298.15 K, Ca(NO 3 ) 2 (aq) solutions readily supersaturate when evaporated isothermally.…”

Section: Introductionmentioning

confidence: 99%

Conversion and optimization of the parameters from an extended form of the ion-interaction model for Ca(NO3)2(aq) and NaNO3(aq) to those of the standard Pitzer model, and an assessment of the accuracy of the parameter temperature representations

Wijesinghe

Rard

2005

The Journal of Chemical Thermodynamics

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The electrolytes Ca(NO 3 ) 2 (aq) and NaNO 3 (aq) are both extremely soluble but differ in several important respects. Ca(NO 3 ) 2 (aq) has complex behavior at low ionic strengths and forms several thermodynamically stable and metastable solid phases, whereas NaNO 3 (aq) forms only an anhydrous solid phase. The thermodynamic properties of both have previously been modeled using extended Pitzer ion-interaction models that include higher-order virial terms, in addition to those of the standard Pitzer model. The parameters of the original Pitzer model, however, are often needed for thermodynamic modeling calculations. In this paper, we convert the parameters of the extended ion-interaction models for Ca(NO 3 ) 2 (aq) and NaNO 3 (aq) to the standard Pitzer model using an extension of the methodology previously described by Rard and Wijesinghe [J. Chem. Thermodyn. 35 (2003) 439-473]. In this variant, the exponential coefficient a P 1 of PitzerÕs model is also optimized to yield the most accurate overall representation of the osmotic coefficients / over the ionic strength and temperature ranges of interest. The optimal values of a P 1 ¼ 0.87 kg 1=2 Á mol À1=2 for Ca(NO 3 ) 2 (aq) and a P 1 ¼ 1.43 kg 1=2 Á mol À1=2 for NaNO 3 (aq) are smaller than the value a P 1 ¼ 2.00 kg 1=2 Á mol À1=2 normally used for electrolytes of these valence types. In both cases, the accuracy of the osmotic coefficients predicted by the standard Pitzer model was nearly equal to that of the extended Pitzer model up to the solubility limit for T = (298.15 to 423.15) K. This result is consistent with the findings of Rard, Wijesinghe, and Wolery [J. Chem. Eng. Data 49 (2004) 1127-1140] who obtained a substantial improvement in model accuracy for Mg(NO 3 ) 2 (aq) at T = 298.15 K by optimizing a P 1 . The use of a temperature-dependent a P 1 that is optimal at each temperature did not yield a significant improvement in accuracy over using a constant optimal value. We also investigated the impact of choosing different temperature functions to develop temperature correlations for the Pitzer parameters. Higher-order temperature functions were needed for evaluations with solubility limited maximum ionic strength compared to evaluations performed at constant maximum ionic strength over the temperature range, especially for Ca(NO 3 ) 2 (aq) because of its more complex thermodynamic behavior. Accurate temperature correlations are presented for both Ca(NO 3 ) 2 (aq) and NaNO 3 (aq).

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Thermodynamics of {zNaCl+(1−z)Na2SO4}(aq) from T=278.15K to T=318.15K, and representation with an extended ion-interaction (Pitzer) model

Cited by 32 publications

References 44 publications

An electrolyte CPA equation of state for mixed solvent electrolytes

An electrolyte CPA equation of state for mixed solvent electrolytes

Isopiestic Investigation of the Osmotic and Activity Coefficients of {yMgCl2+(1−y)MgSO4}(aq) and the Osmotic Coefficients of Na2SO4⋅MgSO4(aq) at 298.15 K

Conversion and optimization of the parameters from an extended form of the ion-interaction model for Ca(NO3)2(aq) and NaNO3(aq) to those of the standard Pitzer model, and an assessment of the accuracy of the parameter temperature representations

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