MODELING SOLUTIONS CONTAINING SPECIFIC INTERACTIONS

Many examples exist of solutions where chemical forces are important. If the chemical forces are quite dominant, a simple ideal chemical theory will generally give better results than any physical model. However, in the majority of systems of interest, both chemical and physical forces are important, and in order to use any combined theory, it is necessary to reduce the number of adjustable parameters by mathematical, thermodynamic, or nonthermodynamic methods. The mathematical methods in general simplify the problem by making it tractable; without some mathematical method one could almost never get enough parameters to use a general chemical-physical theory. The thermodynamic methods are frequently useful but have the disadvantage of being model-dependent, while the spectroscopic methods have the advantage of measuring compositions of chemical complexes directly instead of chemical potential or fugacity. In conclusion, a properly used chemical-physical model is a powerful tool in the rational design of specialty separations. © 1993, American Chemical Society. All rights reserved.