SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2022, Vol. 49 ›› Issue (9): 224-233.DOI: 10.1016/j.cjche.2021.12.007

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Ionic liquids as entrainer in extractive distillation for effectively separating 1-propanol–water azeotropic mixture

Xinqiang You1,2, Kai Zhao1, Ling Li1,2, Ting Qiu1,2   

  1. 1. Fujian Universities Engineering Research Center of Reactive Distillation Technology, Laboratory of Chemical Process Intensification, School of Chemical Engineering, Fuzhou University, Fuzhou 350108, China;
    2. Qingyuan Innovation Laboratory, Quanzhou 362801, China
  • Received:2021-09-19 Revised:2021-12-03 Online:2022-10-19
  • Contact: Ling Li,E-mail:liling@fzu.edu.cn;Ting Qiu,E-mail:tingqiu@fzu.edu.cn
  • Supported by:
    This work was supported by the Natural Science Foundation of Fujian Province, China (2021J01641), National Natural Science Foundation of China (21706062), the Scientific Research Starting Foundation of Fuzhou University, China (GXRC-18073).

Ionic liquids as entrainer in extractive distillation for effectively separating 1-propanol–water azeotropic mixture

Xinqiang You1,2, Kai Zhao1, Ling Li1,2, Ting Qiu1,2   

  1. 1. Fujian Universities Engineering Research Center of Reactive Distillation Technology, Laboratory of Chemical Process Intensification, School of Chemical Engineering, Fuzhou University, Fuzhou 350108, China;
    2. Qingyuan Innovation Laboratory, Quanzhou 362801, China
  • 通讯作者: Ling Li,E-mail:liling@fzu.edu.cn;Ting Qiu,E-mail:tingqiu@fzu.edu.cn
  • 基金资助:
    This work was supported by the Natural Science Foundation of Fujian Province, China (2021J01641), National Natural Science Foundation of China (21706062), the Scientific Research Starting Foundation of Fuzhou University, China (GXRC-18073).

Abstract: Economically separating 1-propanol (NPA) from water is an emergent issue for producing pharmaceutical intermediates such as n-propyl acetate, n-propylamine and so on. In this work, fourionic liquids (ILs) 1-ethyl-3-methylimidazolium thiocyanate ([EMIM][SCN]), 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]), 1,3-dimethylimidazolium methylsulfate ([MMIM][MS]), 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP]) were introduced as potential entrainers for separating NPA–water azeotropic mixture. The results show that [MMIM][MS] is the most suitable entrainer compared with other ILs from the analysis of vapor–liquid equilibrium and relative volatilities. The extractive distillation process with the entrainer regeneration system of flash tank and stripper was employed and optimized by the two-step optimization method. The results show that total annual cost and energy consumption per product flow rate were reduced by 39.79% and 60.47% compared with literature. In addition, the efficiency indicator of extractive section, efficiency indicator of per tray in extractive section, carbon dioxide emissions were also selected as the evaluation index for selection of operating parameters and calculated for different cases. The CO2 emissions of the optimal design can be reduced by 60.98% from environmental aspect.

Key words: Ionic liquids (ILs), Extractive distillation (ED), Process optimization, Energy saving, Evaluation indicator, Optimal design

摘要: Economically separating 1-propanol (NPA) from water is an emergent issue for producing pharmaceutical intermediates such as n-propyl acetate, n-propylamine and so on. In this work, fourionic liquids (ILs) 1-ethyl-3-methylimidazolium thiocyanate ([EMIM][SCN]), 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]), 1,3-dimethylimidazolium methylsulfate ([MMIM][MS]), 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP]) were introduced as potential entrainers for separating NPA–water azeotropic mixture. The results show that [MMIM][MS] is the most suitable entrainer compared with other ILs from the analysis of vapor–liquid equilibrium and relative volatilities. The extractive distillation process with the entrainer regeneration system of flash tank and stripper was employed and optimized by the two-step optimization method. The results show that total annual cost and energy consumption per product flow rate were reduced by 39.79% and 60.47% compared with literature. In addition, the efficiency indicator of extractive section, efficiency indicator of per tray in extractive section, carbon dioxide emissions were also selected as the evaluation index for selection of operating parameters and calculated for different cases. The CO2 emissions of the optimal design can be reduced by 60.98% from environmental aspect.

关键词: Ionic liquids (ILs), Extractive distillation (ED), Process optimization, Energy saving, Evaluation indicator, Optimal design