Results 121 to 130 of about 351 (174)
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A crossover‐UNIQUAC model for critical and noncritical LLE calculations
AICHE Journal, 2015A new model, named the crossover‐UNIQUAC model, has been proposed based on the crossover procedure for predicting constant‐pressure liquid–liquid equilibria (LLE). In this manner, critical fluctuations were incorporated into the classical UNIQUAC equation. Coexistence curves were estimated for systems having a diverse range of asymmetries.
Khalil Parvaneh +2 more
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Fuel, 2015
Abstract A Thermodynamic model that can predict the behavior of the gas sweetening process over the applicable conditions is of vital importance in industry. In this work, Extended UNIQUAC model parameters optimized for the CO 2 -MDEA-H 2 O system are presented. Different types of experimental data consisting of pure MDEA vapor pressure, vapor–liquid
Negar Sadegh +2 more
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Abstract A Thermodynamic model that can predict the behavior of the gas sweetening process over the applicable conditions is of vital importance in industry. In this work, Extended UNIQUAC model parameters optimized for the CO 2 -MDEA-H 2 O system are presented. Different types of experimental data consisting of pure MDEA vapor pressure, vapor–liquid
Negar Sadegh +2 more
exaly +2 more sources
On the combinatorial part of the UNIFAC and UNIQUAC models
The Canadian Journal of Chemical Engineering, 1980AbstractThe excess Cibbs energy of liquid mixtures may be predicted using group contribution models (f.ex. UNIFAC and ASOG), or it may be correlated using molecular models such as UNIQUAC. Group contribution models and the UNIQUAC model contain a combinatorial contribution which accounts for size‐ and shape‐effects and a residual contribution which ...
I. Kikic +3 more
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A modified extended UNIQUAC model for proteins
Fluid Phase Equilibria, 2004A modification of the extended UNIQUAC model is proposed for the description of the non-ideality of protein solutions. Here, the Staverman–Guggenheim combinatorial contribution used in extended UNIQUAC model is replaced by the Flory–Huggins term to take into account the size differences between the protein and solvent.
João A.P. Coutinho +1 more
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On the temperature dependence of the UNIQUAC/UNIFAC models
Chemical Engineering Science, 1980Abstract Local composition models for the description of the properties of liquid mixtures do not in general give an accurate representation of excess Gibbs energy and excess enthalpy simultaneously. The introduction of temperature dependent interaction parameters leads to considerable improvements of the simultaneous correlation.
S. Skjold-Jørgensen +2 more
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On the concentration dependence of the UNIQUAC/UNIFAC models
Chemical Engineering Science, 1982Abstract The UNIQUAC/UNIFAC models can not in general represent vapor-liquid and liquid-liquid equilibria simultaneously with satisfactory results. Recent modifications of the models take into account association and solvation effects by means of chemical theory.
Steen Skjold-Jørgensen +2 more
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A Modified UNIQUAC Model That Includes Hydrogen Bonding
Industrial & Engineering Chemistry Research, 1995Based on the association theory of Wertheim, a UNIQUAC association (UNIQUAC-A) model has been developed in which the hydrogen bond is treated as a strong interaction rather than as a chemical reaction. Compared with the original UNIQUAC model, the UNIQUAC-A model results in better correlations of binary vapor-liquid equilibrium data for self ...
Yuan-Hao Fu +2 more
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Representation of solubilities of amino acids using the uniquac model for electrolytes
Chemical Engineering Science, 1994Abstract A molecular thermodynamic framework for the representation of the solubilities of several binary systems, amino acids—water (nine systems) and peptides—water (five systems), has been developed and tested. The proposed model takes into account simultaneously the chemical and physical equilibrium.
Peres, António M., Macedo, Eugénia A.
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UNIQUAC model for wax solution with pour point depressant
Fluid Phase Equilibria, 2009Abstract It had been shown that after adding pour point depressant (PPD), the diffraction line intensities of paraffin mixtures progressively decreased without any significant variation of the Bragg angle values. This phenomena is due to the structure of paraffin mixture is partly transformed from orthorhombic into hexagonal form.
W.H. Chen +3 more
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Determining the dissociation extent of ionic liquids in water using the PDH + UNIQUAC model
Journal of Molecular Liquids, 2022The main goal of this work was to find a novel way of qualitatively determining the dissociation extent of ionic liquids (ILs) in water, based only on thermodynamic models. The UNIversal QUAsi-Chemical (UNIQUAC) model was applied separately (to account for short-range interactions and considering only neutral molecules) and coupled with the Pitzer ...
Maria Eugénia Macedo +3 more
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