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 energysaving 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.