Separations based on phase equilibria (and thus thermodynamic properties of nonideal liquid mixtures) are often essential for design of efficient chemical processes. Costly and time consuming measurements cannot be made except for a tiny fraction of the enormous number of mixtures of interest. Group contribution methods such as UNIFAC and ASOG show great promise for predicting phase equilibria of nonideal liquid mixtures. However, these methods are presently limited by the available experimental data to describe the group interactions. Previous work directed by Design Institute for Physical Property Data (DIPPR), under AIChE, has made progress in measuring data needed to obtain binary interaction parameters to fill in the blanks in the UNIFAC tables. Much additional work is needed to complete the tables and make the method more generally useful and applicable. Vapor-liquid equilibrium and solubility data are measured for binary liquid mixtures which is used to enhance the group contribution methods. Specific systems are selected taking other work into account to avoid duplication of effort. Significant advantages are realized in the handling of the project by DIPPR, since DIPPR broadly represents the chemical engineering profession and the chemical process industries, has a strong ongoing interest in the results of the projects, selects researchers competitively, and administers projects under contract with the researchers doing the work.
