Liquid-liquid equilibria of aqueous two-phase systems of the ionic liquid brominated N-ethyl pyridine and sodium dihydrogen phosphate, sodium sulfate, ammonium citrate, and potassium tartrate at different temperatures: Experimental determination and corre

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• 作者：Yu-Liang Li ; ^{yulianglee175@chd.edu.cn} ; Meng-Shi Zhang ; Hang Su ; Qian Liu ; Wei-Sheng Guan
• 关键词：Binodal curves ; Liquid&ndash ; liquid equilibrium ; Brominated N-ethyl pyridine ; Aqueous two-phase systems ; Temperature
• 刊名：Fluid Phase Equilibria
• 出版年：2013
• 出版时间：15 March, 2013
• 年：2013
• 卷：341
• 期：Complete
• 页码：70-77
• 全文大小：444 K

文摘

Liquid-liquid equilibrium data have been determined experimentally for aqueous two-phase systems of brominated N-ethyl pyridine ([EPy]Br) and sodium dihydrogen phosphate (NaH₂PO₄) at T = 298.15, 308.15, 318.15, and 328.15 K, and data have also been obtained for aqueous two-phase systems composed of [EPy]Br and sodium sulfate (Na₂SO₄), ammonium citrate (C₆H₅O₇(NH₄)₃) or potassium tartrate (C₄H₄O₆K₂) at T = 298.15 K. The Merchuk equation was used to model the binodal data. The effects of temperature on the binodal curves and tie-lines were studied, and the two-phase area was found to expand with a decrease in temperature, while the slope of the tie lines slightly decreased with an increase in temperature. Furthermore, the effective excluded volume (EEV) values obtained from the binodal model for these systems were determined, and the salting-out abilities follow the order of Na₂SO₄ > NaH₂PO₄ > C₄H₄O₆K₂ > C₆H₅O₇(NH₄)₃. The Othmer-Tobias, Bancroft and several parameter equations were used to determine the correlations of the tie-line data. These models agreed well with the experimental tie-line data.