Correlation of vapor-liquid equilibria for binary mixtures with free energy-based equation of state mixing rules: Carbon dioxide with alcohols, hydrocarbons, and several other compounds

Kwak, Chul; Sandler, Stanley I.; Byun, Hun‐Soo

doi:10.1007/s11814-006-0023-1

Cited by 6 publications

(14 citation statements)

References 45 publications

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“…We instead approximate V 1 as the pure scCO 2 value which can easily be calculated from the density data and V 2 as the infinite dilution values available in the literature. − It is hoped that measuring densities of CO 2 + solute, CO 2 + entrainer, and CO 2 + entrainer + solute will become standard practice for future publications, as these values will generate more accurate values for use within the app. The activity coefficient data can be taken from models such as the nonrandom two liquid (NRTL) model . While the calculation of the KB integrals from experimental data is conceptually straightforward, the practice involves a chain of reasoning that can be cumbersome.…”

Section: The Essence Of the Kirkwood–buff Theorymentioning

confidence: 99%

“…All equations are either well-known in rigorous KB theory or are derived in Appendix B. − The pragmatic use of the low-concentration limit approximations is assumed for the solute. − The steps are as follows: Calculate the pseudochemical potential change of the solute between the entrained and nonentrained solubility cases. Calculate the gradient of pseudochemical potential change with respect to entrainer concentration to create a numerical rather than analytical derivative (eq , l.h.s.). If a richer data set is available, data can be fitted to a polynomial and an analytical derivative can be used. Calculate the denominator term, 1 + c 2 ( G 22 – G 21 ), from activity coefficient data for CO 2 /entrainer using any activity coefficient model, such as NRTL Calculate the preferential solute–entrainer interaction, G u 2 – G u 1 , from the chemical potential change (eq ) and the denominator term. To find both G u 2 and G u 1 , we need a second equation. , This comes from their relationship to the partial molar volume of the solute, V u , which, in turn, is derived from density data.…”

Section: The Essence Of the Kirkwood–buff Theorymentioning

confidence: 99%

“…Calculate the denominator term, 1 + c 2 ( G 22 – G 21 ), from activity coefficient data for CO 2 /entrainer using any activity coefficient model, such as NRTL …”

Section: The Essence Of the Kirkwood–buff Theorymentioning

confidence: 99%

See 2 more Smart Citations

How Entrainers Enhance Solubility in Supercritical Carbon Dioxide

Shimizu

Abbott

2016

J. Phys. Chem. B

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Supercritical carbon dioxide (scCO2) on its own can be a relatively poor solvent. However, the addition at relatively modest concentration of "entrainers", simple solvent molecules such as ethanol or acetone, can provide a significant boost in solubility, thereby enabling its industrial use. However, how entrainers work is still under debate; without an unambiguous explanation, it is hard to optimize entrainers for any specific solute. This paper demonstrates that a fundamental, assumption-free statistical thermodynamic theory, the Kirkwood-Buff (KB) theory, can provide an unambiguous explanation of the entrainer effect through an analysis of published experimental data. The KB theory shows that a strong solute-entrainer interaction accounts for the solubility enhancement, while CO2 density increase and/or CO2-entrainer interactions, which have been assumed widely in the literature, do not account for solubilization. This conclusion, despite the limited completeness of available data, is demonstrably robust; this can be shown by an order-of-magnitude analysis based upon the theory, and can be demonstrated directly through a public-domain "app", which has been developed to implement the theory.

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Section: The Essence Of the Kirkwood–buff Theorymentioning

confidence: 99%

Section: The Essence Of the Kirkwood–buff Theorymentioning

confidence: 99%

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How Entrainers Enhance Solubility in Supercritical Carbon Dioxide

Shimizu

Abbott

2016

J. Phys. Chem. B

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“…However, with the proposals of modern mixing rules such as those involving the excess Gibbs free energy, the equation of state method has been used at high and low pressure mixtures. The mixing rule of Wong and Sandler [13] is one of the most popular approaches currently used and applications to correlate VLE of several mixtures have been presented in the literature [7,14,15]. Therefore, the thermodynamic model considered in this work is the Peng-Robinson equation of state with the mixing rules of Wong and Sandler, using the van Laar model for the Gibbs free energy included in the mixing rules.…”

Section: Introductionmentioning

confidence: 99%

Vapor-liquid equilibrium in low pressure water+congener mixtures

Faúndez

Urbina

Valderrama

2009

Korean J. Chem. Eng.

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Vapor-liquid equilibrium in binary water+congeners mixtures found in alcoholic distillation has been analyzed using the Peng-Robinson equation of state and one of the most popular modern mixing rules, the Wong-Sandler model. Accurate modeling of the concentration of congeners (substances different from ethanol and water) in the vapor phase is of special importance because these substances give some special characteristics of flavor and aroma to the final distilled spirit and also because their concentrations are regulated by law. In the Wong-Sandler mixing rules the van Laar model for the Gibbs excess energy has been used. The type of model used in this work is commonly used to correlate high pressure phase equilibrium and has not yet been used to treat complex low pressure water+congener mixtures as done in this work. Eight binary water+congeners mixtures have been considered for analysis. Comparison with available literature data is done and the accuracy of the model to correlate the pressure and the vapor phase concentration of the congeners is discussed. It is concluded that the model used is accurate enough for distillation analysis, modeling and simulation.

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“…Comparison and evaluation of various mixing rules can be found in the works of Kwak et al [12], LEE et al [13], Mulero et al [14].…”

Section: Introductionmentioning

confidence: 99%

VLE calculation of carbon dioxide+n-alkanes binary mixtures with MHV2 mixing rule

Khodakarami

Naderifar

2008

Korean J. Chem. Eng.

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Vapor-liquid equilibria for binary and asymetric systems include carbon dioxide+C 1 -C 8 , C 10 are calculated by using the Peng-Robinson-Stryjek-Vera equation of state coupled with the modified MHV2 mixing rule. The modified UNIFAC model is used for determining activity coefficient and excess Gibbs free energy. Calculated equilibrium pressures and mole fractions in vapor phase are compared with the experimental data. The average absolute deviation percent (AAD%)s indicates that the error involved in the application of the MHV2 mixing rule by optimized q 1 and q 2 is less than WS and PRSK mixing rules in most cases.

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Correlation of vapor-liquid equilibria for binary mixtures with free energy-based equation of state mixing rules: Carbon dioxide with alcohols, hydrocarbons, and several other compounds

Cited by 6 publications

References 45 publications

How Entrainers Enhance Solubility in Supercritical Carbon Dioxide

How Entrainers Enhance Solubility in Supercritical Carbon Dioxide

Vapor-liquid equilibrium in low pressure water+congener mixtures

VLE calculation of carbon dioxide+n-alkanes binary mixtures with MHV2 mixing rule

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