The solubility of nifedipine (NIF) in binary mixtures of ethanol (EtOH) + water and propylene glycol (PG) + water at 293.2, 298.2, 303.2, 308.2, and 313.2 K was measured. The Jouyban–Acree model and its combination with van’t Hoff equation was used to predict the solubility of NIF in the mixed solvents at different temperatures. The solubility of NIF in EtOH + water mixtures have a maximum at 0.90 mass fraction of EtOH, but the solubility of NIF in PG + water reaches to the maximum value in neat PG. Both mixtures (EtOH + water and PG + water) have a maximum solubility at 313.2 K. A mean relative deviation (MRD) for the fitted data to the Jouyban–Acree model of 8.1% and for combined method of 7.4% was obtained. The predicted MRDs for the solubility data using previously trained models were 38.8%, 43.0%, and 43.9%, and the MRD for predicted density value was 7.3%.

Solubility of anthracene and phenanthrene in binary mixtures of ethanol þ 2,2,4-trimethylpentane at (298.2, 308.2, and 318.2) K are reported. Five numerical methods were used to predict the solubility of anthracene and phenanthrene in the studied binary solvent mixtures, and the mean relative deviation (MRD) was used as an error criterion. The MRD values for studied solvents are in acceptable range. ' INTRODUCTIONPolycyclic aromatic hydrocarbons (PAHs) are among environmental pollutants with very low aqueous solubility values. Anthracene (with aqueous solubility of 0.0076 mg 3 L -1 ) and phenanthrene (with aqueous solubility of 1.20 mg 3 L -1 ) are among the most commonly found PAHs in the environment. 1 Anthracene and phenanthrene are two isomeric forms of the simplest tricyclic aromatic hydrocarbon ( Figure 1) and were used as model compounds in this work. Phenanthrene has lower molecular total energy, and it is more stable than anthracene according to ab initio studies using molecular orbital method in the gas phase. 2 Solubility alteration of chemicals is required in many industrial applications, and the solvent mixing or cosolvency is one of the most frequent and feasible methods used in the industry. Using different ratios of the solvents, a wide range of solubility for a given compound can be achieved. The next parameter which could be employed in the chemical industry is the changing temperature of the system which make a significant contribution in solubilization or crystallization of a compound. Finding an optimum solvent composition and the appropriate temperature in solubility investigations is usually obtained by trial and error which is both time-consuming and costly. ' SOLUBILITY MODELSNumerous predictive models have been introduced to replace the trial-and-error approach or at least reduce the number of required experimental data. 1 One of these models, is the Jouyban-Acree model which correlates the solubility of a solute in binary solvent mixtures at various temperatures. 3where X m,T Sat is the solute mole fraction solubility in the mixed solvents at temperature T; x 1 and x 2 are the mole fractions of solvents 1 and 2 in the absence of the solute; X 1,T Sat and X 2,T Sat denote the mole fraction solubility of the solute in monosolvents 1 and 2; and J i terms are the solvent-solvent and solute-solvent interaction coefficients. Our previous results showed that the model could be trained using the experimental data at 298.2 K and be used to predict the solubility at other temperatures of interest with acceptable error. 4 These coefficients could also be computed using a minimum number of experimental solubility data in binary solvents and then be employed to predict solubility at other solvent compositions. To provide trained versions of the model to predict the solubility in binary solvents without employing solubility data in mixed solvents, a number of attempts were made. The binary interaction terms (J terms) have been correlated with the Hildebrand solubility parameters of the sol...

Solubilities of amlodipine besylate (AMB) in binary mixtures of ethanol (EtOH) + water and propane-1,2-diol or propylene glycol (PG) + water at (293.2, 298.2, 303.2, 308.2, and 313.2) K at atmospheric pressure are reported. In the EtOH + water system, the maximum mole fraction solubility of AMB was observed at 313.2 K and an EtOH mass fraction of 0.65. The corresponding value for PG + water mixtures was obtained in a PG mass fraction of 0.80 at 313.2 K. A combination of the Jouyban–Acree model and van’t Hoff equation was used to predict the solubility of AMB in the mixed solvents at different temperatures. A mean relative deviation of 13.5 % was obtained for the correlated data. The generated solubility data and the derived computations could be used in the pharmaceutical industry where such information is required to speed up the process design.

The effect of injected gas composition (as minimum miscible enrichment) on minimum miscibility pressure (MMP) and respective oil recovery has been studied through numerical slim tube simulation on a wide range of gas compositions. An initial comparative study on the performances of representative equations of state for predicting MMP in slim tube simulations has proven Peng–Robinson equation of state to provide results with better agreement with experimental data. Different injection scenarios are then designed to understand the effects of varying percentages of each component (like CO2) into the injected gas mixture on MMP. MMP decreased when the concentration of CO2 and intermediate components (C2–C6) increased. It was also found that when C7+ content in the injected gas increased, recovery factor decreased significantly. Further investigations on the effect of adding benzene, toluene, and xylene as chemicals into the injected gas (in slim tube simulations) also prove that addition of these aromatics can obviously improve oil recovery and decrease MMP and toluene gives the better results in comparison with the other ones. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.

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