zeotrope is a liquid mixture that shows no local maximum or
minimum when vapour pressure is plotted as a function of
composition.[1] Such a mixture is separable into its component
parts by fractional distillation
azeotropic distillation[1] is any of a range of techniques used
to break an azeotrope in distillation. In chemical engineering,
azeotropic distillation usually refers to the specific technique of
adding another component to generate a new, lower-boiling azeotrope
that is heterogeneous (e.g. producing two, immiscible liquid
phases), such as the example below with the addition of benzene to
water and ethanol. This practice of adding an entrainer which forms
a separate phase is a specific sub-set of (industrial) azeotropic
distillation methods, or combination thereof. In some senses,
adding an entrainer is similar to extractive distillation.
