Economic and exergy analysis of three-product dividing-wall column and double liquid-only side-stream distillation processes

• Published in: Chemical engineering research & design Vol. 200; pp. 729 - 740
• Main Authors: Feng, Zemin, Li, Qiao, Rangaiah, G.P., Leng, Junjie, Fan, Songdi, Wang, Wenhe, Dong, Lichun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2023
• Subjects: Dividing-wall column; Exergy analysis; Liquid-only side-stream distillation; Process design; Process optimization; Process design; Dividing-wall column; Process optimization; Exergy analysis; Liquid-only side-stream distillation
• ISSN: 0263-8762
• DOI: 10.1016/j.cherd.2023.11.022

Dividing-wall column (DWC) is a promising thermally coupled distillation technology for separating multicomponent mixtures. However, the difficulty of controlling vapor split ratio in DWC affects its energy consumption and so limits its wider application in industrial practice. The liquid-only side-stream distillation (LSD) process not only eliminates the vapor split in DWC but also shows comparable economic and thermodynamic efficiency with DWC. This study systematically optimizes and compares the economic performance of DWC and double LSD (DLSD) process for separating ethanol-propanol-butanol ternary mixture, and then analyzes exergy flows in these two processes in detail. Results indicate that TAC of DLSD process is 11.47% lower than that of DWC process, and exergy efficiency of DLSD and DWC processes is 10.81% and 8.57%, respectively. However, both processes exhibit similar exergy destruction in condensers, columns, coolers and reboilers. •Double liquid-only side-stream distillation (DLSD) and dividing-wall column (DWC) are presented and optimized.•Both economic assessment and exergy analysis of DLSD and DWC are carried out.•DLSD has lower annual total cost and higher efficiency than DWC.•DWC and DLSD exhibit similar exergy destruction distributions in columns and heat exchangers.