Finding exact separation boundaries in synthesis and design

Azeotropic, extractive, reactive distillation, and crystallization are among the most widely used techniques for product purification, the separation of chemical or biochemical intermediates, and solvent recovery. A new geometric methodology is presented that shows that exact separation boundaries can be defined through the use of differential geometry and dynamical systems theory and formulated as a constrained global optimization problem. The underlying theory is constructive and therefore leads to several practical algorithms for computing exact separation boundaries in a reliable and efficient manner. The novel approach is based on the observation that, for ternary liquids, separation boundaries correspond to local maxima in the line integral within a given separation region. The proposed approach has widespread application in chemicals and plastics, petroleum products, pharmaceuticals, protein and other bio-separations, the cleaning of medical equipment, metallurgy, and advanced materials. This is an abstract of a paper presented at the AIChE Annual Meeting and Fall Showcase (Cincinnati, OH 10/30/2005-11/4/2005)