Locating All Heterogeneous And Reactive Azeotropes In Multicomponent Mixtures

A novel approach for enclosing all heterogeneous and reactive azeotropes in multi-component mixtures is presented. The thermodynamic conditions for azeotropy form a system of nonlinear equations. A deterministic global optimization approach is introduced in which the global optimization problem may contain multiple global minima and there is a one-to-one correspondence between each global minimum and a potential azeotrope. An algorithm is presented which provides a theoretical guarantee that all global minima can be enclosed. This method is general, and can be applied to mul-ticomponent mixtures that are described by standard thermodynamic models. The problem formulations for nding all heterogeneous azeotropes and for nding all reac-tive azeotropes are presented. The eeectiveness of the proposed approach is illustrated through several example problems using the Wilson, NRTL, UNIQUAC, and UNIFAC activity coeecient equations.