Graphical and stage‐to‐stage methods for reactive distillation column design

Abstract

AbstractBased on the element mass‐balance concept, three graphical methods and one stage‐to‐stage computation method for design of reactive distillation columns have been developed. The element‐based approach allows the design of reactive distillation columns by using simple tools similar to those that are typically employed for nonreactive systems. For example, simple design methods employing reactive McCabe‐Thiele‐ and reactive Ponchon‐Savarit‐type diagrams for design of reactive distillation of binary‐element systems—which may be ternary or higher in terms of mixture compounds—are presented. Also, the driving‐force approach has been extended to employ the element concept for reactive systems. For multielement systems, the design is performed by employing a stage‐to‐stage computation method. For combined reactive distillation columns, comprising both reactive and nonreactive stages, a simple design strategy is proposed, based on the stage‐to‐stage computation method considering reactive and nonreactive bubble‐point calculations. This strategy tracks the conversion or generation and temperature between the feed and the end stages of the column, and indicates when and where nonreactive stages should be added to a reactive distillation column in order to achieve the desired separation. Illustrative examples highlight the application of the design methods, as well as the verification of such designs through rigorous simulation.