This paper presents a framework for finding homogeneous entrainers E to separate non-ideal mixtures AB by extractive distillation. The framework is a systematic approach to convert a Computer Aided Molecular Design into a mixed integer non-linear program (MINLP). It is based on the thermodynamic properties of binary mixtures AE and BE and of isovolatility curve maps of the ternary mixture ABE. Entrainer candidates are ranked by the maximization of the driving force of A and B in their respective mixtures AE and BE as well as by minimizing the entrainer composition xE corresponding to a fixed value of the relative volatility αAB. The framework application is highlighted through an entrainer problem design for the separation of acetone - methanol by extractive distillation process.