A simple screening method for distillation sequence of thermally coupled dividing wall column: distillation sequence morphological analysis method (DSMAM)

Abstract BACKGROUND Distillation is a separation process with a high energy consumption. Therefore, energy‐saving optimizations of the distillation process have become particularly significant. However, developing methods to quickly choose the best energy‐saving distillation sequence for the separation of multiple components has become a key problem. RESULTS In this paper, the Distillation Sequence Morphometry Analysis Method (DSMAM) was established to quickly screen energy‐saving and efficient distillation sequences and was integrated with a Dividing‐wall column (DWC) device, which has more industrial significance. Meanwhile, an evaluation and screening index η of separated multicomponent energy‐saving distillation sequences was proposed. Finally, based on the DSMAM, and combined with Microsoft Visual Basic 6.0 (VB) and Aspen Plus V11 (Aspen) software, a set of distillation sequence screening and evaluation programs of four‐component separation systems was generated. The distillation column sequence with high thermodynamic efficiency and the energy‐saving coupling structure of distillation were obtained quickly and accurately. CONCLUSION This program was applied to the separation of the n‐butane‐benzene‐n‐heptane‐n‐nonane system. It was able to quickly obtain the first three energy‐saving distillation sequences without thermal coupling and the first three energy‐saving distillation sequences in the search space. The direct‐thermal coupling distillation sequence of the energy‐saving fluid was integrated and coupled, providing a preliminary design reference for industrial design and application. © 2022 Society of Chemical Industry (SCI).