化工学报 ›› 2020, Vol. 71 ›› Issue (11): 5067-5079.DOI: 10.11949/0438-1157.20200243

• 热力学 • 上一篇    下一篇

吡啶基离子液体+有机盐双水相体系相图的测定及盐析性能研究

林绪亮1(),徐帅2(),徐少杰1,袁慢景1,陈金珠2,李宇亮2,秦延林1()   

  1. 1.广东工业大学轻工化工学院,广东 广州 510006
    2.长安大学水利与环境学院,旱区地下水文与生态效应教育部 重点实验室,陕西 西安 710064
  • 收稿日期:2020-03-10 修回日期:2020-08-01 出版日期:2020-11-05 发布日期:2020-11-05
  • 通讯作者: 秦延林
  • 作者简介:林绪亮(1988—),男,博士,副教授,xllin@gdut.edu.cn|徐帅(1995—),男,博士研究生,shuaixu012@hotmail.com
  • 基金资助:
    广东省自然科学基金杰出青年项目(2019B151502038);国家自然科学基金项目(21706038);长安大学研究生科研创新实践项目(300103703058)

Phase diagram of pyridyl ionic liquid + organic salt aqueous two-phase system and study of salting-out ability

Xuliang LIN1(),Shuai XU2(),Shaojie XU1,Manjing YUAN1,Jinzhu CHEN2,Yuliang LI2,Yanlin QIN1()   

  1. 1.School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, Guangdong, China
    2.Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, School of Water and Environment, Chang’an University, Xi’an 710064, Shaanxi, China
  • Received:2020-03-10 Revised:2020-08-01 Online:2020-11-05 Published:2020-11-05
  • Contact: Yanlin QIN

摘要:

测定了离子液体N-乙基吡啶四氟硼酸盐([EPy]BF4)+有机盐[丁二酸钠(CH2COONa)2/柠檬酸铵C6H5O7(NH4)3/柠檬酸钠C6H5O7Na3] +水双水相体系在303.15、308.15和313.15 K下的双节线及系线数据。基于相图中的杠杆定律通过质量法研究双水相体系的系线,并用Othmer-Tobias方程、Bancroft方程等经验方程以及NRTL活度系数模型对数据进行关联。采用有效排除体积和Setschenow-type的拟合参数深入研究三种有机盐的盐析能力。结果表明,双节线的三个经验式拟合效果良好,但较多参数的经验式会导致部分参数失去意义;双水相体系的系线满足经验方程,数据可靠性较好,且均方根偏差表明系线数据很好地符合NRTL模型;低温更有利于该双水相体系的形成;三种盐都能和[EPy]BF4离子液体形成双水相体系,且C6H5O7Na3的盐析能力更优。本文提供的数据为离子液体的回收循环利用提供了理论参考依据。

关键词: 离子液体, 相平衡, 盐析, 分离, 双水相

Abstract:

The binodal curve and tie-line data of N-ethylpyridinium tetrafluoroborate ([EPy]BF4) + organic salts [sodium succinate((CH2COONa)2)/ammonium citrate (C6H5O7(NH4)3)/sodium citrate(C6H5O7Na3)] ionic liquid-based aqueous two-phase systems have been studied. The tie-line data were determined using gravimetric method based on the lever rule. Then, the Othmer-Tobias, Bancroft equations and NRTL model were used to fit the data. The effective excluded volume of salt and Setschenow-type equation were used to investigate the salting-out ability of the three salts. As a result, all the three empirical equations fit the binodal curves well, but some redundant parameters may be meaningless. The tie-lines data were satisfactory correlated to the equations, and show that the data is reliable. The root-mean-square deviation (RMSD) indicates tie-lines data fit NRTL model very well. The two-phase systems are easier to form at lower temperatures. All the three salts can form aqueous two-phase system with [EPy]BF4, and C6H5O7Na3 possesses stronger salting-out ability. The data provided in this article provides a theoretical reference for the recycling of ionic liquids.

Key words: ionic liquids, phase equilibrium, salting-out ability, separation, aqueous two-phase system

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