Correlation Of Activity Coefficients Research Articles

Correlation of activity coefficients of water in solutions of sulphuric acid and toluene sulphonic acid

AbstractEquilibrium data are presented for the water‐sulphuric acid‐toluene sulphonic acid system.

Remarks on the determination of the Wilson constants in the correlation of vapour—liquid equilibrium data

For homogenous systems the equation of Wilson has been shown to be very suitable for the correlation of activity coefficients derived from vapour-liquid equilibrium data. A general survey of minimizing criteria and methods suitable for the determination of the constants of this equation is described. This allows their significance and their mutual differences to be elucidated. A method awarding a statistical weight to each experimental point is developed. An attempt is made to determine a quantitative criterion for comparison of correlation methods and to elucidate what part of the deviation got by different methods and/or by means of different sets of data is real and what part is due to the randomness of the data.

Relative volatility and enthalpy data for the systems C4 hydrocarbons‐acetone‐water developed from vapor‐liquid equilibria

AbstractExtractive distillation is widely used in separating C4 hydrocarbons. A typical extractive solvent for such a separation is an acetone‐water mixture. Correct design and selection of optimum operating conditions for extractive distillation towers are ensured by a knowledge of the vapor‐liquid equilibria involved.Pseudo‐binary systems of each of the C4 hydrocarbons, n‐butane, isobutane, butene‐1, and cis‐butene‐2, and acetone‐water solvent were investigated at temperatures of 100°, 150°, and 200°F., at water concentrations of 5, 11, and 17 wt. %, (C4 hydrocarbon‐free) and at hydrocarbon concentrations up to 28 mole %. The results were interpreted as activity coefficients, and showed good consistency. The binary Margules three‐suffix and van Laar two‐suffix equations correlate the measured activity coefficients adequately as a function of concentration.Dependence of activity coefficients on temperature was used to evaluate the differential heats of solution of the hydrocarbons in the acetone‐water solvent. The results were also used to derive partial liquid enthalpy‐concentration curves.Ternary Margules three‐suffix and van Laar two‐suffix equations gave a satisfactory correlation of activity coefficients for pseudo‐ternary systems. The ternary Margules equations were used to calculate relative volatilities, which are presented graphically as functions of temperature and composition.