10 A new UNIQUAC based predictive local composition model is here compared against predictive Wilson and predictive modified UNIQUAC on their abilities to predict wax formation. For that purpose a very large database of phase equilibrium data of both synthetic and real hydrocarbon fluids, at both low and high pressures, will be used. It is shown that the new UNIQUAC model does not suffer from t...

The extended universal quasichemical (UNIQUAC) model is a thermodynamic model for solutions containing electrolytes and nonelectrolytes. The model is a Gibbs excess function consisting of a Debye–Hückel term and a standard UNIQUAC term. The model only requires binary ion-specific interaction parameters. A unique choice of standard states makes the model able to reproduce solid–liquid, vapor–liq...

Solid-liquid equilibria for binary mixtures of {Methyl palmitate (1) + Naphthalene (2)} were measured using differential scanning calorimeter (DSC). Simple eutectic behaviours for this system are observed. The experimental results were correlated by means of the NRTL, Wilson, UNIQUAC and ideal models. The root-mean-square deviations of the solubility temperatures for all measured data vary from...

A 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. This new model allows an excellent description of the activity coefficients ...

In this study, the Langmuir adsorption isotherm has been coupled with activity coefficient models for prediction of surface tension of single and mixed electrolyte solutions. Various activity models such as Meissner, Pitzer and extended UNIQUAC have been used and coupled with Langmuir adsorption isotherm. The model parameters were determined through mathematical optimization using experimental ...

vapor-liquid equilibrium in nh3-co2-h2o system at high pressures has been studied. the uniquac-nrf model for this system was extended by using the goppert 4 maurer reported datas. since the system contains molecules and ionic species the binary interaction parameters considered, where those are of molecule-molecule, molecule-ion and ion-ion types. these interaction parameters are taken as const...

Vapor-liquid equilibrium in NH3-CO2-H2O system at high pressures has been studied. The UNIQUAC-NRF model for this system was extended by using the Goppert 4 maurer reported datas. Since the system contains molecules and ionic species the binary interaction parameters considered, where those are of molecule-molecule, molecule-ion and ion-ion types. These interaction parameters are taken as c...

A predictive version of the UNIQUAC model is proposed for the description of the nonideality of paraffinic solid solutions. With this model, and using only pure component properties, is possible to adequately predict the phase behavior of complex hydrocarbon mixtures. Both liquid and solid phase compositions as well as the fraction of crystals in a partly frozen solution show a good agreement w...

In this work, an electrolyte-UNIQUAC model was developed by replacement of Boltzmann weight binary interaction parameters by the nonextensive Tsallis weight. A summation of the long-range electrostatic term (Debye-Huckel equation) and a short-range interaction term were considered in the calculation of thermodynamic properties. A framework proposed by Chen and co-workers was employed for the de...

the determination region of solubility of methanol with gasoline of high aromatic content was investigated experimentally at temperature of 288.2 k. a type 1 liquid-liquid phase diagram was obtained for this ternary system. these results were correlated simultaneously by the uniquac model. the values of the interaction parameters between each pair of components in the system were obtained for t...