Comparison of stacked side-stream sequences and dividing-wall columns for distillation retrofit
Journal
Separation and Purification Technology
Journal Volume
381
Start Page
135653
ISSN
13835866
Date Issued
2026-02-18
Author(s)
Liu, Hsiao-Te
Abstract
With increasing emphasis on reducing carbon emissions and improving economic efficiency, retrofitting of distillation systems to achieve energy intensification has received growing attention recently. Many researchers have studied the retrofit of conventional sequences to thermally coupled sequences including dividing-wall columns (DWCs). Recently an alternative to thermal coupling called the stacked side-stream sequence (SSS) has been proposed and has been shown to perform better than thermal coupling in many cases. However there have not been any studies published comparing DWCs and SSSs for the case of a retrofit of an existing two-column sequence. In this work DWCs and SSSs are compared in the context of a retrofit of a two column sequence. The method is illustrated using a study of the distillation of an industrial mixture MCM (methylcyclopentane / cyclohexane / methylcyclohexane). An optimized conventional two-column direct sequence (DS) is used as the base case and retrofits into SSSs and DWCs are modeled. Simulated annealing is employed to optimize all process designs to obtain the minimum TAC for each configuration. The results show that the best DWC retrofit reduces energy consumption and cost by 38.43 % and 32.95 % respectively, but the best SSS retrofit does better, reducing energy consumption and cost by 42.75 % and 40.91 % respectively. These findings suggest that SSSs are worthy of consideration as an alternative to DWCs for distillation retrofits.
Subjects
Distillation
Dividing-wall column
Process intensification
Process optimization
Retrofit
Stacked side-stream sequence
SDGs
Publisher
Elsevier B.V.
Type
journal article