TABLE OF CONTENTS The process of distillation can be presented as consisting of numerous states of phase equilibrium between flows of liquid and vapor that have different compositions. Geometric analysis of the distillation process represented in the so-called concentration space ( C) is the main instrument for understanding its regularities.
That is why, before we start the examination of the existing distillation process and its geometric interpretation, it is necessary to consider geometric interpretation, of the phase equilibrium. Numerous methods of calculating phase equilibrium are described in many monographs and manuals (see, e.g., Walas [1985]).
We will not repeat these descriptions but instead will examine only representation of equilibrium states and processes in concentration space.
Molar composition of an n-component mixture is presented as an array that holds molar concentrations of all components:
where m i is the amount of moles of the component i in the mixture.
Concentration space of an n-component mixture C n is a space in which every point corresponds to a mixture of definite composition. Dimensionality of concentration space corresponds to the number of concentrations of components that can be fixed independently.
The ( n ? 1) concentration for an n-component mixture can be fixed independently because concentration of the nth component can be found from Eq. (1.2). That is why the dimensionality of the concentration space of binary mixture C 2 is one, of ternary mixture C 3 ...
