SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2023, Vol. 54 ›› Issue (2): 199-205.DOI: 10.1016/j.cjche.2022.03.021

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Intensified reactive extraction of 4-hydroxypyridine with di(2-ethylhexyl) phosphoric acid in 1-octanol by using tributyl phosphate

Zhixian Chang, Xiangfeng Zhou, Huihua Bai, Deliang Li, Ling Zhang   

  1. Henan Provincial Engineering Research Center of Green Anticorrosion Technology for Magnesium Alloys, Henan Engineering Research Center for Control and Remediation of Soil Heavy Pollution, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, China
  • Received:2021-10-15 Revised:2022-03-29 Online:2023-05-11 Published:2023-02-28
  • Contact: Deliang Li,E-mail:lideiang@henu.edu.cn;Ling Zhang,E-mail:zhangling@henu.edu.cn
  • Supported by:
    The work was supported by the Science and Technology Research Project of Henan Province (192102310490 and 212102310505).

Intensified reactive extraction of 4-hydroxypyridine with di(2-ethylhexyl) phosphoric acid in 1-octanol by using tributyl phosphate

Zhixian Chang, Xiangfeng Zhou, Huihua Bai, Deliang Li, Ling Zhang   

  1. Henan Provincial Engineering Research Center of Green Anticorrosion Technology for Magnesium Alloys, Henan Engineering Research Center for Control and Remediation of Soil Heavy Pollution, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, China
  • 通讯作者: Deliang Li,E-mail:lideiang@henu.edu.cn;Ling Zhang,E-mail:zhangling@henu.edu.cn
  • 基金资助:
    The work was supported by the Science and Technology Research Project of Henan Province (192102310490 and 212102310505).

Abstract: The efficient separation of amphoteric organic compounds from dilute solutions is of great importance in the industrial field. In the present work, the reactive extractions of 4-hydroxypyridine (4-HP) with tributyl phosphate (TBP), di(2-ethylhexyl) phosphoric acid (D2EHPA) and TBP + D2EHPA dissolved in 1-octanol were investigated, respectively. The influences of the initial concentrations of TBP, D2EHPA and TBP + D2EHPA on distribution ratio (D) were discussed, as well as the reactive extraction mechanism were proposed. The obvious intensification effect was observed when the mixture of TBP and D2EHPA was used as extractant. The best extraction conditions were found to be of the molar ratio of D2EHPA and TBP at 2:1 and the equilibrium aqueous pH at 3.50–4.50. D values increased with the increase of the total concentration of TBP and D2EHPA in 1-octanol. Especially, the analysis on the extraction mechanisms clearly indicate (i) TBP in 1-octanol shows negligible reactive extraction toward 4-HP, (ii) D2EHPA in 1-octanol exhibits moderate extraction effect by forming 4-HP:D2EHPA (1:1) and 4-HP:2D2EHPA (1:2) type complexes, while (iii) D2EHPA in TBP/1-octanol demonstrates the maximum distribution ratio with the 4-HP:D2EHPA (1:1) type complex domination. The discussion provides new insights on the mechanism and opens a new way for the intensified extraction of amphoteric organic compounds by using the mixture of multiple extractants in the diluent.

Key words: 4-Hydroxypyridine, Di(2-ethylhexyl)phosphoric acid, Tributyl phosphate, Reactive extraction, Intensified extraction

摘要: The efficient separation of amphoteric organic compounds from dilute solutions is of great importance in the industrial field. In the present work, the reactive extractions of 4-hydroxypyridine (4-HP) with tributyl phosphate (TBP), di(2-ethylhexyl) phosphoric acid (D2EHPA) and TBP + D2EHPA dissolved in 1-octanol were investigated, respectively. The influences of the initial concentrations of TBP, D2EHPA and TBP + D2EHPA on distribution ratio (D) were discussed, as well as the reactive extraction mechanism were proposed. The obvious intensification effect was observed when the mixture of TBP and D2EHPA was used as extractant. The best extraction conditions were found to be of the molar ratio of D2EHPA and TBP at 2:1 and the equilibrium aqueous pH at 3.50–4.50. D values increased with the increase of the total concentration of TBP and D2EHPA in 1-octanol. Especially, the analysis on the extraction mechanisms clearly indicate (i) TBP in 1-octanol shows negligible reactive extraction toward 4-HP, (ii) D2EHPA in 1-octanol exhibits moderate extraction effect by forming 4-HP:D2EHPA (1:1) and 4-HP:2D2EHPA (1:2) type complexes, while (iii) D2EHPA in TBP/1-octanol demonstrates the maximum distribution ratio with the 4-HP:D2EHPA (1:1) type complex domination. The discussion provides new insights on the mechanism and opens a new way for the intensified extraction of amphoteric organic compounds by using the mixture of multiple extractants in the diluent.

关键词: 4-Hydroxypyridine, Di(2-ethylhexyl)phosphoric acid, Tributyl phosphate, Reactive extraction, Intensified extraction