ABSTRACT
Distillation is a physical method or process for separating a liquid mixture into its constituents. One important development in distillation technology was the discovery that a simple distillation, operated on a continuous basis, could have its effect multiplied through the use of staging, i.e., operating several flash vaporizations in series with liquid residue in counterflow. The chapter presents basic theory and conventional practice in the design or analysis of distillation systems, with general orientation. The basic building block for stagewise distillation processes is the contacting stage. The fundamental basis for the process of distillation is the natural equilibrium between liquid and vapor phases of a system of chemical components. The equilibrium ratio involves physical equilibrium between phases. The involved system may be binary or multicomponent, and ideal or nonideal according to the terminology of solution thermodynamics. Azeotropic distillation involves a system with one or more azeotropes. Frequently the liquid and vapor compositions of the azeotrope are identical.
