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square-well-potentials
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A modified square well model in obtaining the surface tension of pure and binary mixtures of hydrocarbons
, Article Journal of Chemical Thermodynamics ; Volume 40, Issue 7 , 2008 , Pages 1131-1135 ; 00219614 (ISSN) ; Taghikhani, V ; Ghotbi, C ; Ayatollahi, S ; Sharif University of Technology
2008
Abstract
A model based on the perturbation theory of fluids was proposed to correlate the experimental data for surface tension of pure hydrocarbons in a wide range of temperature. The results obtained for the pure hydrocarbons were directly used to predict the surface tension for binary hydrocarbon mixtures at various temperatures. In the proposed model, a modified form of the square well potential energy between the molecules of the reference fluid was taken into account while the Lennard-Jones dispersion energy was considered to be dominant amongst the molecules as the perturbed term to the reference part of the model. In general, the proposed model has three adjustable parameters which are chain...
Modeling electrolyte solutions with the SAFT-VR equation using Yukawa potentials and the mean-spherical approximation
, Article Fluid Phase Equilibria ; Volume 236, Issue 1-2 , 2005 , Pages 241-255 ; 03783812 (ISSN) ; Patel, B. H ; Galindo, A ; Ghotbi, C ; Sharif University of Technology
Elsevier
2005
Abstract
An equation of state based on the statistical associating fluid theory for potentials of variable range (SAFT-VR) is used to model 7 hydrogen-bonding solvents and 23 electrolyte solutions. Solvent-solvent hydrogen bonding interactions are explicitly taken into account as in other versions of the SAFT approach. In addition, long-range Coulombic interactions between ionic species are accounted for using the non-restricted mean-spherical approximation, while solvent-solvent and solvent-ion dispersion interactions are included and are treated using Yukawa potentials. Previously a similar approach had been proposed in which the dispersion interactions were treated using square-well potentials. In...
The effect of steepness of soft-core square-well potential model on some fluid properties
, Article Molecular Physics ; Volume 106, Issue 1 , 2008 , Pages 103-112 ; 00268976 (ISSN) ; Parsafar, G. A ; Sharif University of Technology
2008
Abstract
The effect of repulsive steepness of the soft-core square well (SCSW) potential model on the second virial coefficient, critical behaviour (two- phase region and the position of critical point), and coordination number are investigated. The soft-core thermodynamic perturbation theory (TPT) presented by Weeks-Chandler-Anderson (WCA) recently developed by Ben-Amotz and Stell (BAS) has been used for the reference system, and the Barker-Henderson TPT for the perturbed system. The Barker-Henderson macroscopic compressibility approximation has been used for all order perturbation terms in which the second-order one is improved by assuming that the molecules in every two neighbouring shells are...
Experimental Determination & Thermodynamic Modeling of Solubility of Gases in Ionic Liquids
,
M.Sc. Thesis
Sharif University of Technology
;
Ghotbi, Cyrus
(Supervisor)
;
Behzadi, Bahman
(Supervisor)
;
Jalili, Amir Hossein
(Supervisor)
;
Ahmadi, Amir Naser
(Co-Advisor)
Abstract
Ionic liquids (IL's) are found to be potentially suitable solvents for the chemical process industry, especially due to their negligible vapor pressure which can result in a major decrease of solvent loss and the environmental harm. One of the foreseeable industrial applications in the field of natural gas processing is the replacement of traditional organic solvents (usually alkanol amines) presently used for the absorption of H2S from sour gases, by suitable IL's. Ionic liquids have been proposed for the separation of gas mixtures. In particular, ionic liquids have been suggested for the removal of the acid gases, hydrogen sulfide, and carbon dioxide, from natural gases and refinery gases....
Thermodynamic modeling of hydrogen sulfide solubility in ionic liquids using modified SAFT-VR and PC-SAFT equations of state
, Article Fluid Phase Equilibria ; Volume 309, Issue 2 , 2011 , Pages 179-189 ; 03783812 (ISSN) ; Behzadi, B ; Ghotbi, C ; Sharif University of Technology
2011
Abstract
Equations of state based on the statistical associating fluid theory for potentials of variable range (SAFT-VR) and the perturbed chain statistical associating fluid theory (PC-SAFT) have been used to model the PVT behavior of ionic liquids and the solubility of H2S in six imidazolium-based ionic liquids. The studied systems included [bmim][PF6], [hmim][PF6], [bmim][BF4], [hmim][BF4], [bmim][NTF2] and [hmim][NTF2] at various temperatures and pressures.For pure components, parameters of the models have been obtained by fitting the models to experimental data on liquid densities; the average relative deviation between the calculated and experimental densities for ionic liquids is less than...