Prediction Of Liquid-liquid Equilibria Research Articles

LIQUID-LIQUID EQUILIBRIA OF ORGANIC COMPOUNDS: MEASUREMENT, CORRELATION AND PREDICTION†

The knowledge of phase equilibria is an important step in the development of extraction processes. This knowledge is usually gained from experiments. However, this procedure is expensive when a suitable solvent has to be found for a specific separation. Therefore methods for predicting phase equilibria are needed. While formerly these methods were largely based on empirical assumptions, the use of the concept of local compositions by Wilson6 offers a semi-empirical approach. There is one disadvantage of this approach: the parameters of models like UNIQUAC or NRTL have to be fitted to different types of data, to liquid-liquid equilibria (LLE) for the immiscible pairs of components and to vapour-liquid equilibria (VLE) or other data for the miscible pairs in a system with mutual solubility. To demonstrate the problem we performed measurements in the binary systems: n-octane/aniline and methylcylohexane/aniline. of both liquid-liquid equilibrium and vapour-liquid equilibrium: for the second type of measurements ebulliomeiry was used. The prediction of LLE has been improved with two new concepts. One is based on the well-known UNIFAC method. The use of the Lyngby-Dorlmund data bank made it possible to determine a new parameter table merely based on LLE data. The second method is based on common UNIQUAC parameters which have been determined with the data base.

Liquid-liquid equilibrium data: Their retrieval, correlation and prediction Part I: Retrieval

Part one of this series of articles contains a status report covering the published liquid-liquid equilibrium data for binary and multicomponent mixtures with organic components. Different methods of measuring liquid-liquid equilibrium data are briefly mentioned, and a new, computerized data bank for storage and retrieval of the data is described. This part will be followed by articles on the correlation and prediction of liquid-liquid equilibria.

Prediction of liquid-liquid equilibria by an analytical solutions of groups.

Prediction of liquid-liquid equilibria by an analytical solutions of groups.