A Simple Screening Method for Distillation Sequence of Thermally Coupled Dividing Wall Column: Distillation Sequence Morphological Analysis Method (DSMAM)

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 eta 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.(c) 2022 Society of Chemical Industry (SCI).