A generalized expression for the ratio of the critical temperature to the critical pressure with the van der Waals surface area

Kontogeorgis, Georgios M.; Yakoumis, Iakovos; Coutsikos, Philippos; Tassios, Dimitrios P.

doi:10.1016/s0378-3812(97)00174-x

Cited by 15 publications

(27 citation statements)

References 29 publications

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“…The

\frac{T_{c}}{P_{c}}

ratios of 21 polar n‐alkanols have been calculated using seven predictive methods, generally of the GC type, that is, the Joback, 57 Lydersen, 58 Ambrose, 59,60 Constantinou & Gani, 61 Kontogeorgis 26 , and Khademi et al 32 models. The results are reported in Table 8.…”

Section: Resultsmentioning

confidence: 99%

“…The results are reported in Table 8. Note that as recommended by the authors themselves, an increment value of 0.584 has been adopted for calculation of the UNIFAC Q parameter of the hydroxyl group (OH) in Equation (1) 26 …”

Section: Resultsmentioning

confidence: 99%

“…As a case study, the performances of the Joback, 57 Lydersen, 58 Ambrose, 59,60 Constantinou & Gani, 61 and Kontogeorgis 26 GC methods in prediction of the

\frac{T_{c}}{P_{c}}

ratio of 21 n‐alkanols, from methanol to 1‐docosanol, have been investigated. Notice that although not strictly a GC method, the Kontogeorgis 26 model could exclusively be applied in tandem with the UNIFAC GC tables 31 . Along the same line, the relation proposed by Khademi et al 32 , based on the ideal gas heat capacity, has also been included to ensure a comprehensive comparative study with the model developed in the current study.…”

Section: Methodsmentioning

confidence: 99%

“…Taking a cue from, and concurrently substantiating this supposition, several studies have indicated that the

\frac{T_{c}}{P_{c}}

ratio can be correlated much better than either property individually 23‐25 . In particular, expanding upon the study by Bae et al, 2 Kontogeorgis and co‐workers have advocated in a series of publications 26‐29 that it is possible to relate the

\frac{T_{c}}{P_{c}}

ratio of high molecular weight compounds to a single parameter, that is, the compound's normalized van der Waals surface area ( Q ) given by Bondi 30 and reported in the UNIFAC GC tables 31 as:

\frac{T_{c}}{P_{c}} ((), normalK . {bar}^{- 1}) = 9.0673 + 0.43309 ((), Q^{1.3} + Q^{1.95})

…”

Section: Introductionmentioning

confidence: 98%

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Estimation of the critical properties of compounds using volume‐based thermodynamics

Hekayati

Raeissi

2020

AIChE Journal

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The importance, yet scarcity of the critical constants of thermally unstable fluids warrants the development of reliable methods for the estimation of these essential thermodynamic properties. A thorough investigation undertaken in this study on 1,589 compounds belonging to 83 chemical classes, indicated that the ratio of critical temperature to critical pressure Tc Pc of both low and high molecular weight compounds could be well expressed in terms of their volumetric properties. In addition, two new methodologies are presented for estimating V c , as well as an indirect approach for prediction of T c from surface tension data, altogether allowing the calculation of Z c. Moreover, comparative studies are made with five group contribution methods. It is also demonstrated that by employing the Peng-Robinson EOS, and without prior knowledge of the critical properties, it is possible to calculate various thermophysical properties including P sat. , T b , ρ sat: liq: , ΔH vap. , C p , and even the T c and P c themselves.

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“…The

\frac{T_{c}}{P_{c}}

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“…As a case study, the performances of the Joback, 57 Lydersen, 58 Ambrose, 59,60 Constantinou & Gani, 61 and Kontogeorgis 26 GC methods in prediction of the

\frac{T_{c}}{P_{c}}

Section: Methodsmentioning

confidence: 99%

“…Taking a cue from, and concurrently substantiating this supposition, several studies have indicated that the

\frac{T_{c}}{P_{c}}

\frac{T_{c}}{P_{c}}

ratio of high molecular weight compounds to a single parameter, that is, the compound's normalized van der Waals surface area ( Q ) given by Bondi 30 and reported in the UNIFAC GC tables 31 as:

\frac{T_{c}}{P_{c}} ((), normalK . {bar}^{- 1}) = 9.0673 + 0.43309 ((), Q^{1.3} + Q^{1.95})

…”

Section: Introductionmentioning

confidence: 98%

See 2 more Smart Citations

Estimation of the critical properties of compounds using volume‐based thermodynamics

Hekayati

Raeissi

2020

AIChE Journal

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“…Due to molecular packing (which exists in the liquid as well as the solid state), this co-volume is expected to be higher than the molecular (or vdW) volume. The following equation can be used for screening estimation methods: [19][20][21] T c P c ¼ 9:0673 þ 0:433 09 Q 1:3 w þ Q 1:95 The reason for including b ¼ 1:41 V w in Table 3.4 lies in the well-accepted picture for the liquid state that each molecule has about 10 neighbor molecules, i.e.…”

Section: Pure Compoundsmentioning

confidence: 99%

Cubic Equations of State: The Classical Mixing Rules

Kontogeorgis

Folas

2009

Thermodynamic Models for Industrial Applications

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Cubic equations of state are classical high-pressure models. From a thermodynamic point of view, the term 'high pressure' refers to pressures high enough so as to have a significant effect on the thermodynamic properties of both phases, typically over 15-20 bar. High-pressure vapor-liquid equilibria (VLE) can be more complex than low-pressure VLE, since at high pressures both phases are non-ideal. At low pressures, the main source of non-ideality is the liquid phase. The non-ideality of the vapor phase at low pressures is typically about 10% and it can be estimated by, for example, corresponding states methods or the virial equation. K-charts and the Chao-Seader are popular methods for high-pressure VLE calculations for systems containing hydrocarbons and gases. By far, though, the most popular method is the equations of state, especially the cubic ones. In most cases, high-pressure VLE as found in nature and the chemical industry apply to mixtures with at least one subcritical and one supercritical component. In many oil-and gas-related systems, hydrocarbons are present together with gases (methane, ethane, CO 2 , N 2 , etc.) and sometimes water is also present.The two-and especially the three-parameter cubic equations of state (EoS) represent a family of classical but still very useful and widely applied engineering models. The most well-known EoS are the van der Waals (vdW), Redlich-Kwong (RK) (now mostly of historical value) and especially the Soave-Redlich-Kwong (SRK) and Peng-Robinson (PR) equations; the last two are typically employed in the petroleum and chemical industries. Such cubic EoS are still the primary choice of models today for petrochemicals, gas processing and air separation. 1,2 The most well-known cubic EoS together with the typical expressions often used for estimating their parameters are shown in Table 3.1.With reference to Table 3.1 and the methods shown for the estimation of the EoS parameters: T c is the critical temperature, P c is the critical pressure and T r is the reduced temperature (¼ T=T c ); and the generalization of the energy parameter as a function of temperature and the acentric factor, v, was first proposed by Soave. 5 The acentric factor, introduced by Pitzer, represents a measure of the acentricity (non-sphericity) of the molecule:v ¼ Àlog P sat r j Tr¼0:7 À 1:00 ð3:1Þwhere P sat r is the reduced vapor pressure (¼ P sat =P c ).

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ACEOS – The additive and constitutive equation of state in the n-alkane homologous series

Arenas-Quevedo

Martínez-Vitela

Gracia-Fadrique

2022

Chemical Thermodynamics and Thermal Analysis

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A generalized expression for the ratio of the critical temperature to the critical pressure with the van der Waals surface area

Cited by 15 publications

References 29 publications

Estimation of the critical properties of compounds using volume‐based thermodynamics

Estimation of the critical properties of compounds using volume‐based thermodynamics

Cubic Equations of State: The Classical Mixing Rules

ACEOS – The additive and constitutive equation of state in the n-alkane homologous series

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