ABSTRACT
When the azeotrope is homogeneous, the separation cannot be achieved in a single column. An azeotrope exists when the composition of the liquid phase is the same as that of the vapor phase.
= NC where xi = mole fraction of component j in the liquid, yi is the mole fraction of component j in the vapor and NC is the number of components. An azeotrope presents a distillation boundary or limitation to the achievable separation. If there is no composition difference between the vapor and the liquid, compositions cannot change from tray to tray, so there is no further separation. The azeotrope forms a pinch condition.
