Resume of the extension of the Ponchon and Savarit method for designing ternary rectification columns

Abstract

This work presents a summary of the analytical extension of the classical Ponchon and Savarit method for the design of binary distillation columns to ternary systems. For a given feasible separation, convergence is almost always guaranteed in calculation times comparable to those used by commercial simulation packages. However, in this case the total number of stages and the optimal feed location are simultaneously determined. For ternary mixtures it is possible graphical representation keeping all the intuitive characteristics of the original method for binary mixtures. The presented approach include the possibility of approximate (with interpolation, correlation and intersection methods) or rigorous calculations of mass and energy balances and equilibrium relations and the direct calculation of the minimum number of equilibrium stages and the optimum feed point location for a specific product separation with a specified reflux ratio. The distillate flow rate and the reflux ratio can be optimised in an outer loop providing the method a great flexibility.