Thermally Coupled Distillation

Abstract

This paper presents a brief overview in the design of mixed thermally coupled-heat integrated distillation sequences. The approach considers from conventional columns (each distillation column with a condenser and a reboiler) to fully thermally coupled systems (only one reboiler and one condenser in the entire system). The advantages and disadvantages of thermally coupled distillation in comparison with conventional columns are discussed; the consequence is that the optimal configuration is usually an intermediate point between fully thermally coupled systems and conventional systems. The paper also includes 1. Structural relations between separation tasks and number of column sections, logical relationships that separation tasks must obey in order to select only feasible solutions avoiding configurations that are always sub-optimal. 2. The convenience of using a task based approach instead a column based approach to avoid the redundancy due to thermally couple configurations. 3. How to take advantage of thermodynamically equivalent configurations to synthesize more operable configurations. 4. Heat integrated – thermally coupled distillation systems.