SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2023, Vol. 59 ›› Issue (7): 135-145.DOI: 10.1016/j.cjche.2022.12.009

• Full Length Article • 上一篇    下一篇

A dynamic control structure of liquid-only transfer stream distillation column

Borui Liu1, Tao Zhang1, Yi Zheng1, Kailong Li1, Hui Pan2, Hao Ling1   

  1. 1. State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China;
    2. Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
  • 收稿日期:2022-07-13 修回日期:2022-12-18 出版日期:2023-07-28 发布日期:2023-10-14
  • 通讯作者: Hui Pan,E-mail:fiona_panhui@shiep.edu.cn;Hao Ling,E-mail:linghao@ecust.edu.cn
  • 基金资助:
    This work is supported by National Natural Science Foundation of China (21908056), Shanghai Sailing Program (19YF1410800) and Science and Technology Commission of Shanghai Municipality (19DZ2271100).

A dynamic control structure of liquid-only transfer stream distillation column

Borui Liu1, Tao Zhang1, Yi Zheng1, Kailong Li1, Hui Pan2, Hao Ling1   

  1. 1. State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China;
    2. Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
  • Received:2022-07-13 Revised:2022-12-18 Online:2023-07-28 Published:2023-10-14
  • Contact: Hui Pan,E-mail:fiona_panhui@shiep.edu.cn;Hao Ling,E-mail:linghao@ecust.edu.cn
  • Supported by:
    This work is supported by National Natural Science Foundation of China (21908056), Shanghai Sailing Program (19YF1410800) and Science and Technology Commission of Shanghai Municipality (19DZ2271100).

摘要: The intention of this fundamental work is to explore the manipulation of a mixture of benzene, toluene and o-xylene separated from liquid-only transfer divided-wall column (LTS-DWC). First, two control structures are clearly proposed, including seven component control loops (CS1) and seven temperature control loops (CS2). However, two control structures can handle ±10% feed disturbances rather than larger feed disturbances. Subsequently, an equivalent four-column model by introducing withdraw ratio is developed to discuss the effect of two liquid-only side-stream on the overall reboiler duty. It is indicated that the second liquid-only side-stream withdraw ratio strongly affects the overall energy consumption. Hence, six-component control loops within the fixed second liquid-only side-stream withdraw ratio (CS3) is proposed and the purity of products returns to set value even as facing ±20% feed disturbances. Finally, based on the above results, it is established a temperature control structure (CS4) for controlling fixed second liquid-only side-stream withdraw ratio, which can cope with ±15% disturbances. Inspired by these findings, an insight into the dynamic control of LTS-DWC promotes the industrial implementation of DWC through new liquid-only side-stream configurations.

关键词: Separation, Divided-wall column, Liquid-only transfer stream, Optimal design, Dynamic modeling

Abstract: The intention of this fundamental work is to explore the manipulation of a mixture of benzene, toluene and o-xylene separated from liquid-only transfer divided-wall column (LTS-DWC). First, two control structures are clearly proposed, including seven component control loops (CS1) and seven temperature control loops (CS2). However, two control structures can handle ±10% feed disturbances rather than larger feed disturbances. Subsequently, an equivalent four-column model by introducing withdraw ratio is developed to discuss the effect of two liquid-only side-stream on the overall reboiler duty. It is indicated that the second liquid-only side-stream withdraw ratio strongly affects the overall energy consumption. Hence, six-component control loops within the fixed second liquid-only side-stream withdraw ratio (CS3) is proposed and the purity of products returns to set value even as facing ±20% feed disturbances. Finally, based on the above results, it is established a temperature control structure (CS4) for controlling fixed second liquid-only side-stream withdraw ratio, which can cope with ±15% disturbances. Inspired by these findings, an insight into the dynamic control of LTS-DWC promotes the industrial implementation of DWC through new liquid-only side-stream configurations.

Key words: Separation, Divided-wall column, Liquid-only transfer stream, Optimal design, Dynamic modeling