Critical parameters optimized for accurate phase behavior modeling for heavy n-alkanes up to C100 using the Peng–Robinson equation of state

AbstractThe thermodynamics of fluids in confined (capillary) media is different from the bulk conditions due to the effects of the surface tension, wettability, and pore radius as described by the classical Kelvin equation. This study provides experimental data showing the deviation of propane vapour pressures in capillary media from the bulk conditions. Comparisons were also made with the vapour pressures calculated by the Peng–Robinson equation-of-state (PR-EOS). While the propane vapour pressures measured using synthetic capillary medium models (Hele–Shaw cells and microfluidic chips) were comparable with those measured at bulk conditions, the measured vapour pressures in the rock samples (sandstone, limestone, tight sandstone, and shale) were 15% (on average) less than those modelled by PR-EOS.

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Curvature-Based Equation of State for Microemulsion-Phase Behavior

SPE Journal ◽

10.2118/194022-pa ◽

2018 ◽

Vol 24 (02) ◽

pp. 647-659 ◽

Cited By ~ 2

Author(s):

V. A. Torrealba ◽

R. T. Johns ◽

H.. Hoteit

Keyword(s):

Equation Of State ◽

Phase Behavior ◽

Oil Recovery ◽

Industrial Applications ◽

Data Availability ◽

Behavior Modeling ◽

Average Curvature ◽

Wide Range ◽

Definition Of ◽

Spheroidal Geometry

Summary An accurate description of the microemulsion-phase behavior is critical for many industrial applications, including surfactant flooding in enhanced oil recovery (EOR). Recent phase-behavior models have assumed constant-shaped micelles, typically spherical, using net-average curvature (NAC), which is not consistent with scattering and microscopy experiments that suggest changes in shapes of the continuous and discontinuous domains. On the basis of the strong evidence of varying micellar shape, principal micellar curves were used recently to model interfacial tensions (IFTs). Huh's scaling equation (Huh 1979) also was coupled to this IFT model to generate phase-behavior estimates, but without accounting for the micellar shape. In this paper, we present a novel microemulsion-phase-behavior equation of state (EoS) that accounts for changing micellar curvatures under the assumption of a general-prolate spheroidal geometry, instead of through Huh's equation. This new EoS improves phase-behavior-modeling capabilities and eliminates the use of NAC in favor of a more-physical definition of characteristic length. Our new EoS can be used to fit and predict microemulsion-phase behavior irrespective of IFT-data availability. For the cases considered, the new EoS agrees well with experimental data for scans in both salinity and composition. The model also predicts phase-behavior data for a wide range of temperature and pressure, and it is validated against dynamic scattering experiments to show the physical significance of the approach.

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Phase Behavior Modeling of Alkyl−Amine + Water Mixtures and Prediction of Alkane Solubilities in Alkanolamine Aqueous Solutions with Group Contribution with Association Equation of State

Industrial & Engineering Chemistry Research ◽

10.1021/ie100421m ◽

2010 ◽

Vol 49 (15) ◽

pp. 7085-7092 ◽

Cited By ~ 15

Author(s):

Francisco A. Sánchez ◽

Ticiana M. Soria ◽

Selva Pereda ◽

Amir H. Mohammadi ◽

Dominique Richon ◽

...

Keyword(s):

Equation Of State ◽

Aqueous Solutions ◽

Phase Behavior ◽

Group Contribution ◽

Behavior Modeling ◽

Alkyl Amine

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Thermodynamic and Phase Behavior of Supercritical Water: Environmentally Significant Organic Chemical Mixtures

Heat Transfer, Volume 2 ◽

10.1115/imece2004-59453 ◽

2004 ◽

Author(s):

S. Artemenko ◽

V. Mazur

Keyword(s):

Equation Of State ◽

Phase Behavior ◽

Supercritical Water ◽

Water Oxidation ◽

New Technologies ◽

Critical Parameters ◽

Binary Interaction ◽

Organic Chemical ◽

Saturation Curve ◽

Mixture Phase

The importance of equation of state models is fundamental to new technologies such as supercritical water oxidation for the destruction of organic pollutants. In order to be able to perform hazard and risk assessments, the parameters ofthermodynamic models are considered as information characteristics of chemicals that store the knowledge on their thermodynamic, phase and environmental behavior. Considering the extremely large number of existing chemicals, it is obvious that there is need for developing theoretically sound methods for the prompt estimation of their phase behavior in aquatic media at supercritical conditions. Recent developments of the global phase equilibria studies of binary mixtures provide some basic ideas of how the required methods can be developed based on global phase diagrams for visualization of the phase behavior of mixtures. The mapping of the global equilibrium surface in the parameter space of the equation of state (EoS) model provides the most comprehensive system of criteria for predicting binary mixture phase behavior. The main types of phase behavior for environmentally significant organic chemicals in aqueous environments are considered using structure-property correlations for the critical parameters of substances. Analytic expressions for azeotropy prediction for cubic EoS are derived. A local mapping concept is introduced to describe thermodynamically consistently the saturation curve of water. The classes of environmentally significant chemicals (polycyclic aromatic hydrocarbons - PAH, polychlorinated biphenyls - PCB, polychlorinated dibenzo-p-dioxins and furans, and selected pesticides) are considered and main sources of the property data are examined. Vapor pressure, heat of vaporization, and critical parameter estimations for pure components were chosen for seeking a correlation between the octanol–water partition coefficients KOW and the EoS binary interaction parameters - k12. The assessment of thermodynamic and phase behavior of representatives for different pollutants is given.

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