Jerzy J. Kosinski

Vapour pressure of binary, three-phase (S-L-V) systems and solubility

Abstract Solubilities and vapour pressures along the solid-liquid equilibrium line for systems 2- t -butyl-4-methylphenol+benzene, 2- t -butyl-4-methylphenol+cyclohexane, 2,6-di- t -butyl-4-methylphenol+benzene, 2,6-di- t -butyl-4-methylphenol+cyclohexane and enthalpies of fusion for six phenols have been measured. The effect of specific interactions, leading to association, on solubilities and vapour pressures of 13 binary three-phase systems (S—L—V) has been discussed. Results of solubility prediction from vapour pressure measurements and vice versa are presented.

Equation of state for high-temperature aqueous electrolyte and nonelectrolyte systems

Abstract An equation of state has been developed for the representation of the phase behavior of high-temperature and supercritical aqueous systems containing salts and nonelectrolytes. The equation includes a reference part that is based on a model for hard-sphere ion pairs and dipolar solvent molecules. In addition to the reference part, the equation contains a perturbation part, which is expressed by a truncated virial-type expansion. To enhance the predictive capability of the EOS for normal fluids such as hydrocarbons, the equation has been reformulated using the three-parameter corresponding-states principle. For salt–water systems for which little experimental information is available, a predictive procedure has been developed that relies on similarities in the fluid phase behavior of various salt–water systems. This procedure utilizes the equation of state for NaCl+H 2 O as a prototype system and introduces a transformation of parameters for the salt of interest. The equation accurately represents vapor–liquid equilibria, solid–liquid equilibria and densities for systems containing water, salts and hydrocarbons.

Solid-liquid-vapour equilibrium of binary systems

Abstract Vapour pressures have been measured along the solid-liquid equilibrium lines for systems benzoic acid + hexane, naphthalene + hexane and naphthalene + cyclohexane. The effect of specific and nonspecific interactions on the solubilities and vapour pressures of 10 binary three-phase systems (S - L - V) has been discussed. Predictions of solubility from vapour pressure measurements and vice versa are presented. An equation proposed earlier has been used and compared with the UNIQUAC equation.

Vapour-liquid equilibrium of dialkylphenols in cyclohexane

Abstract The vapour pressure of solutions of 4-tert-butyl-2-methylphenol, 2-tert-butyl-5-methylphenol, 2-tert-butyl-6-methylphenol, 2,6-di-iso-propylphenol and 2,6-di-tert-butylphenol in cyclohexane at 298.15 and 323.15 K have been measured. The vapour pressure and activity coefficients determined on the basis of the thermodynamic properties of monosubstituted phenols have been compared with those predicted by the UNIFAC method. The influence of the steric hindrance around the hydroxyl group on the structure and thermodynamic properties of the solutions has been examined.

Liquid-liquid equilibrium in binary polar aromatic + hydrocarbon systems

Abstract The liquid-liquid coexistence curves for the systems: 4-chlorophenol + hexadecane, 2-methoxyphenol + hexadecane and phenol + hexadecane have been determined by measuring the temperature of disappearance of turbulence. The literature and our data have been represented on the basis of the scaling theory. The analysis of the critical point indicates that the mean value of the mean association number of phenol in various hydrocarbons is equal to 3.11, confirming that the privileged structure of phenol associates is a trimer. The mean value of the mean association number, λ, of polar compounds not forming intermolecular hydrogen bonds in various hydrocarbons is equal to 2.06 and confirms that the privileged structure of associates is a dimer. The obtained outcomes bear out previous results of the analyses of solid-liquid and solid-liquid-vapour equilibrium data for the same or similar systems. The prediction of the liquid-liquid equilibrium critical point composition has been proposed on the basis of the previously determined relationships between the association and the structure of polar aromatic compounds.

Vapour pressure and association of phenols

Abstract A comparative method of analysing the vapour pressure data of polar compounds and their homomorphs is used to determine the standard Gibbs energy of association of polar molecules. A method of predicting the standard Gibbs energy of association of poly-substituted phenols is proposed on the basis of substituent contributions. The vapour pressures of pure liquids and association constants can be predicted using this method.

An algorithm for multiphase equilibrium calculations for systems containing polymers

A comprehensive algorithm has been developed for multiphase equilibrium computations in multicomponent systems. The algorithm includes stability analysis and calculation of equilibrium compositions by a combination of a multiphase direct substitution method and Gibbs energy minimization. The algorithm has been specially designed to handle the numerical complexities that are characteristic of systems containing large (polymeric) and small molecules. Such complexities include a very strong composition dependence of equilibrium ratios (K-factors) as well as frequent occurrence of extremely low equilibrium concentrations and fugacity or activity coefficients.