Long chain multifunctional molecules with GC-PPC-SAFT: Limits of data and model

Rozmus, Justyna; Hemptinne, Jean-Charles de; Ferrando, Nicolas; Mougin, Pascal

doi:10.1016/j.fluid.2012.06.004

Cited by 24 publications

(25 citation statements)

References 37 publications

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“…A retrospective analysis of the third-order perturbation term has shown that calculations using the empirical expression of Eq. (38) are in good agreement with evaluations of the equivalent term obtained from molecular simulation, 73 which indicates that the series is convergent and terms beyond the third-order make a reduced contribution to the Helmholtz free energy.…”

Section: Nksupporting

confidence: 76%

“…The methodology was then extended to account explicitly for interactions due to polarity (based on the treatment of Gubbins and Twu 33 ) for the study of light and heavy esters, 34 and has since been applied to a wide range of systems including polycyclic hydrocarbons, 35 ethers, aldehydes, ketones, 36 amines, 37 and long-chain multifunctional molecules including alkanediols and alkanolamines. 38 Alongside the aforementioned SAFT-based group contribution methods, other techniques have been developed where molecular properties are not calculated as functions of the occurrences of functional groups alone, but also account for the positioning of the groups in the molecule by defining superstructures. In the context of GC methods this invariably involves a consideration of second-order groups (as in the work of Constantinou and Gani 10 ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Group contribution methodology based on the statistical associating fluid theory for heteronuclear molecules formed from Mie segments

Papaioannou

Lafitte

Avendaño

et al. 2014

The Journal of Chemical Physics

255

429

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A group contribution method for associating chain molecules based on the statistical associating fluid theory (SAFT-) The Journal of Chemical Physics 127, 234903 (2007) (2013)] is formulated within the framework of a group contribution approach (SAFT-γ Mie). Molecules are represented as comprising distinct functional (chemical) groups based on a fused heteronuclear molecular model, where the interactions between segments are described with the Mie (generalized Lennard-Jonesium) potential of variable attractive and repulsive range. A key feature of the new theory is the accurate description of the monomeric group-group interactions by application of a high-temperature perturbation expansion up to third order. The capabilities of the SAFT-γ Mie approach are exemplified by studying the thermodynamic properties of two chemical families, the n-alkanes and the n-alkyl esters, by developing parameters for the methyl, methylene, and carboxylate functional groups (CH 3 , CH 2 , and COO). The approach is shown to describe accurately the fluid-phase behavior of the compounds considered with absolute average deviations of 1.20% and 0.42% for the vapor pressure and saturated liquid density, respectively, which represents a clear improvement over other existing SAFT-based group contribution approaches. The use of Mie potentials to describe the group-group interaction is shown to allow accurate simultaneous descriptions of the fluid-phase behavior and second-order thermodynamic derivative properties of the pure fluids based on a single set of group parameters. Furthermore, the application of the perturbation expansion to third order for the description of the reference monomeric fluid improves the predictions of the theory for the fluid-phase behavior of pure components in the near-critical region. The predictive capabilities of the approach stem from its formulation within a group-contribution formalism: predictions of the fluid-phase behavior and thermodynamic derivative properties of compounds not included in the development of group parameters are demonstrated. The performance of the theory is also critically assessed with predictions of the fluid-phase behavior (vapor-liquid and liquid-liquid equilibria) and excess thermodynamic properties of a variety of binary mixtures, including polymer solutions, where very good agreement with the experimental data is seen, without the need for adjustable mixture parameters.

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Section: Nksupporting

confidence: 76%

Section: Introductionmentioning

confidence: 99%

Group contribution methodology based on the statistical associating fluid theory for heteronuclear molecules formed from Mie segments

Papaioannou

Lafitte

Avendaño

et al. 2014

The Journal of Chemical Physics

255

429

View full text Add to dashboard Cite

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“…Using the proposed analysis, the ePPC-SAFT electrolyte model initially proposed by Rozmus et al [113] is further refined, using improved water parameters and a dielectric constant that allows working with mixed solvents. Two ion-specific parameters are fitted on activity coefficients and densities of various alkali halides.…”

Section: Resultsmentioning

confidence: 99%

“…Physically, the Statistical Associating Fluid Theory (SAFT) is based on statistical perturbation theory where perturbation terms are used to correct the Helmholtz energy of a reference system. This work propose the use of the GC-ePPC-SAFT electrolyte model by Rozmus et al [90,113] as a basis. It is based on PC-SAFT [56] and extended to polar molecules [114][115][116] of Jog and Chapman theory for multipolar molecules [117] ("`?…”

Section: The Saft Equation Of Statementioning

confidence: 99%

Modeling of mixed-solvent electrolyte systems

Ahmed

Ferrando

Hemptinne

et al. 2018

Fluid Phase Equilibria

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Models for mixed-solvent strong electrolytes, using an equation of state (EoS) are reviewed in this work. Through the example of ePPC-SAFT (that includes a Born term and ionic association), the meaning and the effect of each contribution to the solvation energy and the mean ionic activity coefficient are investigated. The importance of the dielectric constant is critically reviewed, with a focus on the use of a salt-concentration dependent function. The parameterization is performed using two adjustable parameters for each ion: a minimum approach distance () and an association energy (). These two parameters are optimized by fitting experimental activity coefficient and liquid density data, for all alkali halide salts simultaneously, in the range 298K to 423K. The model is subsequently tested on a large number of available experimental data, including salting out of Methane/Ethane/CO 2 /H 2 S. In all cases the deviations in bubble pressures were below 20% AADP. Predictions of vapor-liquid equilibrium of mixed solvent electrolyte systems containing methanol, ethanol are also made where deviations in bubble pressures were found to be below 10% (AADP).

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“…External consistency is established by comparing the data with those of similar systems. Some authors propose mapping the behaviour of compounds of the same chemical family to observe trends, and hence evaluate the quality of the data on whether or not they agree with the trend [26,27]. This analysis requires substantial expertise, because unexpected deviations from family trends may occur (some examples can be the smallest family members, oddeven effects, or steric effects in molecules).…”

mentioning

confidence: 99%

Data quality and assessment, validation methods and error propagation through the simulation software: Report from the Round-Table Discussion at the 10th World Congress of Chemical Engineering in Barcelona (October 1–5, 2017)

2018

Chemical Engineering Research and Design

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The issues of data quality and propagation of data uncertainties into process design and plant specifications are of great current interest. Hence, two Working Parties of the European Federation of Chemical Engineers (EFCE) organized a Round Table Discussion on the topic, as part of the World Congress of Chemical Engineering (WCCE10) in Barcelona, in October 2017. The discussion was guided by industrial and academic experts, with the audience as a key part of the discussion, trying to find some answers in three areas: Data acquisition and evaluation of experimental uncertainties, tools for data reconciliation to improve their quality, and impact of data uncertainties on the process at the end. Several concrete stories are presented that demonstrate the importance of considering data quality and all possible contributions to the uncertainty of chemical process design. Difficulties associated with data quality are discussed at various levels: (1) the experimentalists (measurement issues, evaluation of uncertainties, use of consistency analysis tools); (2) model developers (capture of adequate physics, parameter regression strategies, uncertainty propagation), (3) vendors of process simulation software, and (4) process engineers (who are responsible at the end). Paths for improvements were proposed through better and more efficient communication among different participants, as well as through education.

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Long chain multifunctional molecules with GC-PPC-SAFT: Limits of data and model

Cited by 24 publications

References 37 publications

Group contribution methodology based on the statistical associating fluid theory for heteronuclear molecules formed from Mie segments

Group contribution methodology based on the statistical associating fluid theory for heteronuclear molecules formed from Mie segments

Modeling of mixed-solvent electrolyte systems

Data quality and assessment, validation methods and error propagation through the simulation software: Report from the Round-Table Discussion at the 10th World Congress of Chemical Engineering in Barcelona (October 1–5, 2017)

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