Control properties of driving force based distillation columns design

Abstract

So far, not much is known about the controllability of distillation columns derived from algorithms as there are many types of algorithms exist and many forms of mixtures to be separated. It is therefore aimed in this study to analyse the controllability of a distillation columns design method, known as the driving force approach. This study makes use of a four stage methodology and those stages are; sequence design, energy comparison, sensitivity comparison, and controllability comparison. In the first stage, a distillation columns sequence is designed based on the driving force algorithm. In the second stage, the energy consumption of the different designs is compared. In the third stage, the sensitivity of the different designs is compared and in the final stage the relative gain array method is used to determine the interaction between the designs’ control loops. The methodology is applied to a five component hydrocarbon mixture. Results showed that while the driving force design is the most energy efficient and robust, it does not have the best controllability.