Modeling of multiphase liquid equilibria for multicomponent mixtures

García-Sánchez, Fernando; Schwartzentruber, Jacques; Ammar, M.; Renon, H.

doi:10.1016/0378-3812(96)03025-7

Cited by 34 publications

(30 citation statements)

References 30 publications

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“…This objective function was minimized using the isoactivity criterion in all components for the calculation of the distribution coefficients. With these estimated parameters, the liquid-liquid equilibrium flash calculation [32] was applied to evaluate the compositions of the tie line by using the experimental total compositions as input data. The other part of the data was used for prediction.…”

Section: Parameter Estimation and Data Correlationmentioning

confidence: 99%

Liquid–Liquid Equilibria of Water + 1-Butanol + Amino Acid (Glycine or dl-Alanine or l-Leucine) at 313.15 K

2014

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Amino acids play an important role both in animal metabolism and in industrial processes. Since they are rarely found in nature in a free form, they must be obtained by biosynthesis or protein hydrolysis, often resulting in aqueous mixtures containing various solutes including several types of amino acids. As a consequence, the cost of the separation processes and concentration of amino acids can be as high as 90 % of their total manufacturing cost. In this way, the design of such processes requires knowledge of the partitioning behavior in two-phase systems and thermodynamic models should support this optimization procedure. However, both the complexity of biomolecules, due to their multiple functional groups, and the crucial role of water make the standard available thermodynamic models unattractive for the computation of phase behavior. Therefore, new thermodynamic models for the description of the phase behavior of systems containing biomolecules are required. In this work, liquid-liquid equilibrium data of the ternary systems 1-butanol ? water ? amino acid (glycine, DL-alanine or L-leucine) were measured at 313.15 K. The experimental results were correlated and interaction parameters were estimated for the modified-NRTL, UNIFAC and UNIFAC-Campinas models. The modified-NRTL model was able to describe the data better than the UNIFAC and UNIFACCampinas models.

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Section: Parameter Estimation and Data Correlationmentioning

confidence: 99%

Liquid–Liquid Equilibria of Water + 1-Butanol + Amino Acid (Glycine or dl-Alanine or l-Leucine) at 313.15 K

2014

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“…These systems are not usually correlated ( [13] Vol. 2, p. 69) or, sometimes, partial regressions are found: for example, in some papers the LLLE tie-triangle is correlated and the three partially miscible binaries are predicted with the previously optimized parameters [29], which often lead to serious deviations in the LLE data for the binary subsystems.…”

Section: Condensed Phase Equilibrium Regression Backgroundmentioning

confidence: 99%

“…However, regressions for only one of the regions of a complex system (e.g. type 3 or 4) are frequently found in the literature [29,32]. Consequently, the obtained parameters, which do not describe all the equilibrium regions existing in the system, can lead to serious problems when they are used in chemical process simulation packages.…”

Section: Condensed Phase Equilibrium Regression Backgroundmentioning

confidence: 99%

GE Models and Algorithms for Condensed Phase Equilibrium Data Regression in Ternary Systems: Limitations and Proposals

Gomis¹

2011

TOTHERJ

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Phase equilibrium data regression is an unavoidable task necessary to obtain the appropriate values for any model to be used in separation equipment design for chemical process simulation and optimization. The accuracy of this process depends on different factors such as the experimental data quality, the selected model and the calculation algorithm. The present paper summarizes the results and conclusions achieved in our research on the capabilities and limitations of the existing G E models and about strategies that can be included in the correlation algorithms to improve the convergence and avoid inconsistencies. The NRTL model has been selected as a representative local composition model. New capabilities of this model, but also several relevant limitations, have been identified and some examples of the application of a modified NRTL equation have been discussed. Furthermore, a regression algorithm has been developed that allows for the advisable simultaneous regression of all the condensed phase equilibrium regions that are present in ternary systems at constant T and P. It includes specific strategies designed to avoid some of the pitfalls frequently found in commercial regression tools for phase equilibrium calculations. Most of the proposed strategies are based on the geometrical interpretation of the lowest common tangent plane equilibrium criterion, which allows an unambiguous comprehension of the behavior of the mixtures. The paper aims to show all the work as a whole in order to reveal the necessary efforts that must be devoted to overcome the difficulties that still exist in the phase equilibrium data regression problem.

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“…There are only a few studies regarding the numerical solution of the threeliquid equilibrium problem [6,9,10]. Stateva et al [2] discussed the difficulties and dangers associated with the correct determination of the LLLE solution when local optimisation methods are used.…”

Section: Introductionmentioning

confidence: 99%

“…They are especially important in the petroleum engineering industry where surfactants are used to recover residual oil [3][4][5]. Usually, systems which are effective in improving oil recovery are characterized by three-liquid equilibrium phases which appear and disappear as the concentration of one or more components is varied over ranges that are encountered during displacement through porous media [6]. The design of chemical flooding processes and the interpretation of process performance require an understanding of the phase behaviour of these systems [7,8].…”

Section: Introductionmentioning

confidence: 99%

Gibbs energy based procedure for the correlation of type 3 ternary systems including a three-liquid phase region

Marcilla¹,

Olaya²,

Serrano³

et al. 2009

Fluid Phase Equilibria

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Equilibrium data for type 3 ternary systems comprising a liquid-liquid-liquid equilibrium region (LLLE tie-triangle) are not frequently correlated, as is evidenced by a lack of studies in the literature. In the present paper, a robust algorithm to calculate or correlate equilibrium data for this type of system is proposed. This algorithm is based on geometric aspects related to the Gibbs energy of mixing (g M ) and possesses some interesting advantages that are discussed in the text. The methodology put forward is applied to correlate the equilibrium data of three type 3 ternary systems. The NRTL model is used to define g M , and the common tangent plane criterion to define the equilibrium condition for the calculations. The lack in flexibility of the NRTL equation to model these systems is discussed.

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Modeling of multiphase liquid equilibria for multicomponent mixtures

Cited by 34 publications

References 30 publications

Liquid–Liquid Equilibria of Water + 1-Butanol + Amino Acid (Glycine or dl-Alanine or l-Leucine) at 313.15 K

Liquid–Liquid Equilibria of Water + 1-Butanol + Amino Acid (Glycine or dl-Alanine or l-Leucine) at 313.15 K

GE Models and Algorithms for Condensed Phase Equilibrium Data Regression in Ternary Systems: Limitations and Proposals

Gibbs energy based procedure for the correlation of type 3 ternary systems including a three-liquid phase region

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