The Generalized van der Waals Partition Function as a Basis for Equations of State

Sandler, Stanley I.; Lee, K.-H.; Kim, H.

doi:10.1021/bk-1986-0300.ch008

Cited by 11 publications

(9 citation statements)

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“…At infinite pressure, they constrained the EOS excess Gibbs free energy to be equal to the ACM excess Gibbs free energy. Sandler and co-workers − proposed a reformulation of these mixing rules to avoid some drawbacks. The predictive abilities of these Wong–Sandler mixing rules for describing the behavior of complex mixtures have been demonstrated for a variety of systems; nevertheless, the number of interaction parameters produced and the high degree of correlation among those parameters limited the application of these mixing rules.…”

Section: Resultsmentioning

confidence: 99%

Representation and Prediction of Vapor–Liquid Equilibrium Using the Peng–Robinson Equation of State and UNIQUAC Activity Coefficient Model

Dadmohammadi

Gebreyohannes

Abudour

et al. 2016

Ind. Eng. Chem. Res.

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Many important processes in the oil and gas industry (e.g., distillation, absorption, extraction) involve contact between liquid and vapor phases. The reliable design of these industrial processes requires accurate thermodynamic models to describe the vapor−liquid equilibrium (VLE) of the mixtures of interest. Two common approaches, γ−ϕ and ϕ−ϕ, are utilized to describe such VLE behavior. In this study, we present a comprehensive assessment of the representation and predictive capability of these two approaches, utilizing the UNIQUAC model to determine the activity coefficients and the Peng−Robinson (PR) equation of state to calculate the fugacity coefficients. The assessment was completed using a diverse binary VLE database consisting of 916 binary systems involving 140 compounds belonging to 31 chemical classes. Both the overall results and the results categorized for highly nonideal systems and for aqueous systems are presented within the context of internal and external consistency tests. Specifically, regressed and generalized parameters are utilized in internal and external consistency tests, respectively. Further, the phase behavior of sample systems was analyzed using Danner's molecular classification method based on the mNRTL1 parameter and G E /RT values. For the systems considered, the regression results show that the γ−ϕ approach represents the VLE behavior more precisely compared to the ϕ−ϕ approach. The overall results using the γ−ϕ approach exhibit an absolute average deviation (% AAD) of 1.6, 0.1, 4.5, and 5.7 for the pressure, temperature, mole fraction, and equilibrium constant (K), respectively. The ϕ−ϕ approach regression results are within 3 times the error of the γ−ϕ approach. A similar trend was observed for the quantitative structure−property relationship generalized predictions. The γ−ϕ approach predicts the VLE behavior more accurately compared to the ϕ−ϕ approach. The overall results based on the γ−ϕ approach exhibit % AADs of 5.1, 0.4, 5.9, and 8.1 for the pressure, temperature, mole fraction, and K, respectively. The ϕ−ϕ approach generalized predictions are within 2 times the error obtained from the γ−ϕ approach. The results of Danner's molecular classification of the phase behavior indicated that systems with similar components are more likely to produce nearly ideal mixture behavior and systems involving dissimilar components are more likely to produce nonideal mixture behavior. Further, the quality of the representations for the ϕ−ϕ approach are generally good for most system classifications with the exception of adequate or poor fits observed for strongly polar−strongly polar and aqueous−strongly polar systems.

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Section: Resultsmentioning

confidence: 99%

Representation and Prediction of Vapor–Liquid Equilibrium Using the Peng–Robinson Equation of State and UNIQUAC Activity Coefficient Model

Dadmohammadi

Gebreyohannes

Abudour

et al. 2016

Ind. Eng. Chem. Res.

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“…During the past few years, we have developed extensions of cubic equations of state for confined fluids in different geometries 25,30 based on the Generalized van der Waals Theory. 35 The key results are expressions for the Helmholtz energy as a function of temperature, volume, and component amounts, from which expressions for all other thermodynamic properties can be derived. Herein, we follow the methodology reported previously.…”

Section: Conditionmentioning

confidence: 99%

Adsorption of Gases on Zeolitic Imidazolate Frameworks: Modeling with Equations of State for Confined Fluids and Pore Size Distribution Estimation

Barbosa

Travalloni

Tavares

et al. 2019

Ind. Eng. Chem. Res.

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Certain gas separations, as that of propene from propane, are difficult and costly via methods such as distillation, conventionally used in oil and gas industries. Membrane-based separations using metal organic frameworks (MOFs) and, in particular, zeolitic imidazolate frameworks (ZIFs) are potential candidates for less expensive and more energyefficient processes. Two effects define the performance of a given separation: diffusion and adsorption equilibrium. This works focuses on the latter: the adsorption equilibrium of gases on ZIFs has been correlated and predicted using an equation of state for confined fluids, which extends the Peng−Robinson model, widely used for process design in the oil and gas industries. Excellent agreement between experimental and calculated adsorption isotherms is obtained. In addition, we fitted pore size distributions (PSDs), under the initial assumption that these PSDs might present multiple peaks. In all cases, the fitted PSDs presented a single, narrow peak, which is consistent with the well-defined pore structure of the investigated ZIFs.

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“…This gives the basic structure of the van der Waals equation of state, which was explored in different ways by Longuet-Higgins [27] and Widom [28] in the 1960s. The perturbed hard-chain theory (PCHT) and its variants were explored in the 1970s and 1980s by Beret [29], Donohue [30], Sandler [31], and Prausnitz [32]. SAFT also includes the necessary term for the formation of chains, and it is intrinsically able to model large molecules such as polymers and proteins (A chain ).…”

confidence: 99%

Life, data, and everything

Satyro

2007

Pure and Applied Chemistry

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The use of thermodynamics for the solution of chemical and process engineering problems is determined by a blend of science, engineering, art, and grit. Although chemical engineering thermodynamics benefits from an ever-increasing body of basic scientific knowledge, the solution of real problems still depends very much on the knowledge of individuals, their creativity, and their determination to recommend solutions. The essence of success is determined by a combination of two apparently simple components-physical property data and how they are used.

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The Generalized van der Waals Partition Function as a Basis for Equations of State

Cited by 11 publications

References 0 publications

Representation and Prediction of Vapor–Liquid Equilibrium Using the Peng–Robinson Equation of State and UNIQUAC Activity Coefficient Model

Representation and Prediction of Vapor–Liquid Equilibrium Using the Peng–Robinson Equation of State and UNIQUAC Activity Coefficient Model

Adsorption of Gases on Zeolitic Imidazolate Frameworks: Modeling with Equations of State for Confined Fluids and Pore Size Distribution Estimation

Life, data, and everything

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