Geometrical Tools for Teaching Azeotropy Using Simplified Thermodynamic Models

In this work we propose a geometric view of the azeotropy problem, using some simplified models. We demonstrate that the occurrence of azeotropes in binary mixtures can be viewed-geometrically-as the intersection of curves in the plane (for some models, these curves are parabolas). Furthermore, the idea of functions from the plane to the plane is used to help understand the azeotropic phenomenon. These ideas are illustrated with two simple cases, with one and two azeotropes, allowing the analysis of a unusual thermodynamic behavior-such as double azeotropy-with simple mathematical tools, by undergraduate students in Chemical Engineering courses.