A systematic study of methanol+n-alkane vapor–liquid and liquid–liquid equilibria using the CK-SAFT and PC-SAFT equations of state

The cubic-plus-association (CPA) model is an equation of state (EoS) that combines the Soave−Redlich−Kwong (SRK) equation with the association term from Wertheim's theory as used in statistical associating fluid theory (SAFT). In the form used here, the CPA EoS does not include separate terms for the polar and quadrupolar contributions. The capabilities and limitations of the CPA model when it is applied to mixtures with nonpolar and polar chemicals, as well as associating (hydrogenbonding) compounds are illustrated. Three case studies are considered, all of which are of industrial relevance. The capabilities of the model are illustrated in the first two case studies: the phase behavior of mixtures used in the oxidation of 2-octanol in supercritical CO 2 and the investigation of systems containing acetone, methanol, water, chloroform, and methyl acetate. In each case, both correlations of vapor−liquid and liquid−liquid equilibria for binary systems and predictions for multicomponent mixtures are presented. Finally, the limitations of the CPA model are illustrated in the last case study, which focuses on the modeling of mixtures containing aromatic acids, such as benzoic and terephthalic acid. We also include a detailed discussion of the capabilities and limitations of the model in context and related to previous investigations. Finally, results are compared to observations from studies with other association models.

show abstract

“…Moreover, increasing k ij /T trend has been reported for two SAFT variants by Yarrison and Chapman 93 for methanol−alkanes.…”

Section: Discussionmentioning

confidence: 69%

Capabilities and Limitations of an Association Theory for Chemicals in Liquid or Supercritical Solvents

Tsivintzelis

Kontogeorgis

2012

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…Instead, we use a nomenclature, where association schemes are defined by the total number of associating sites, x, the number of proton acceptor sites, y, and the number of proton donor sites, z, written as x(y:z). This definition is identical to the one used by Yarrison and Chapman 17 and by Avlund et al 18 Three glycolethers have been considered in this work: 2-methoxyethanol (C 1 E 1 ), 2-ethoxyethanol (C 2 E 1 ), and 2-butoxyethanol (C 4 E 1 ). The structures of the three glycol ethers are shown in Figure 3.…”

Section: Articlementioning

confidence: 95%

Application of Simplified PC-SAFT to Glycol Ethers

Avlund

Kontogeorgis

Michelsen

2011

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

The simplified PC-SAFT (sPC-SAFT) equation of state is applied for binary glycol ether-containing mixtures, and it is investigated how the results are influenced by inclusion of intramolecular association in the association theory. Three different glycol ethers are examined: 2-methoxyethanol, 2-ethoxyethanol, and 2-butoxyethanol. VaporÀliquid and liquidÀliquid equilibria of miscible and immiscible, self-and cross-associating mixtures are considered, including the closed-loop liquidÀliquid equilibrium of 2-butoxyethanolÀwater. The results are finally compared to other association models.

show abstract

“…Most studies use either the two-site (2B) or the three-site (3B) scheme [2,3,5,7,8,14], but the best phase equilibrium results are obtained when the 2B scheme is used [5,7]. Good VLE results are obtained for mixtures of alcohols with alkanes as well as for cross-associating systems, often better than those when all SAFT parameters are fitted to vapor pressures and liquid densities, but in some case using additional properties (than vapor pressures and liquid densities) in the parameter estimation yields improved pure compound parameters in association equations of state [7].…”

Section: Methanol and Ethanolmentioning

confidence: 99%

“…Good VLE results are obtained for mixtures of alcohols with alkanes as well as for cross-associating systems, often better than those when all SAFT parameters are fitted to vapor pressures and liquid densities, but in some case using additional properties (than vapor pressures and liquid densities) in the parameter estimation yields improved pure compound parameters in association equations of state [7]. It is concluded from these investigations that it is possible using quantum chemistry to eliminate one of the two association parameters of SAFT, but typically not both [2,15]. The remaining parameters must be fitted to vapor pressure and liquid density data.…”

Section: Methanol and Ethanolmentioning

confidence: 99%

Correlation and prediction of liquid–liquid equilibria for alcohol/hydrocarbon mixtures using PC-SAFT equation of state at high pressure up to 150 MPa

NguyenHuynh¹

2016

Fluid Phase Equilibria

View full text Add to dashboard Cite

A systematic study of methanol+n-alkane vapor–liquid and liquid–liquid equilibria using the CK-SAFT and PC-SAFT equations of state

Cited by 57 publications

References 33 publications

Capabilities and Limitations of an Association Theory for Chemicals in Liquid or Supercritical Solvents

Capabilities and Limitations of an Association Theory for Chemicals in Liquid or Supercritical Solvents

Application of Simplified PC-SAFT to Glycol Ethers

Correlation and prediction of liquid–liquid equilibria for alcohol/hydrocarbon mixtures using PC-SAFT equation of state at high pressure up to 150 MPa

Contact Info

Product

Resources

About