Abstract:

Experimental determination of the liquid-liquid equilibrium system provides basic data for accurate simulation, design and process development of solvent extraction and recovery. In this work, methyl isopropyl ketone (MIPK) was chosen as the extraction agent and the liquid-liquid equilibrium of methyl isopropyl ketone-phenol-hydroquinone-water was studied since phenol and hydroquinone are typical monophenols and polyphenols in the coal chemical industry wastewater. The liquid-liquid equilibrium data were determined at 40℃ under atmospherics pressure. The experimental data were correlated with the NRTL and UNIQUAC models. The binary interaction parameters of the quaternary systems were obtained. The LLE results calculated by the NRTL and UNIQUAC models agreed quite well with the experimental data with root mean square deviations below 0.190% and 0.266% for these two models. Furthermore, the extraction process was simulated with binary interaction parameters calculated from the UNIQUAC model. According to these simulations, the total phenols and total polyphenols in the phenolic wastewater could respectively decrease from 12700 mg×L^-1 to 300 mg×L^-1 and from 4250 mg×L^-1 to 299 mg×L^-1 under the operation condition of extraction temperature 40℃, extraction stages 5 and solvent to wastewater ratio 1:7.72.

Key words: methyl isopropyl ketone, hydroquinone, phase equilibria, solvent extraction, simulation

摘要：

液液相平衡测定为溶剂萃取及回收的准确模拟、设计和过程开发提供基础数据。以甲基异丙基甲酮为萃取剂，在处理高浓煤化工含酚废水的三元液液相平衡萃取基础上，选定其中典型单元酚苯酚和多元酚对苯二酚为代表物，测定甲基异丙基甲酮-苯酚-对苯二酚-水在常压40℃下的液液相平衡数据。采用NRTL和UNIQUAC活度系数模型对实验数据进行热力学关联，回归得到该四元体系的二元交互作用参数。结果表明该模型可以很好地关联实验数据，两种模型的相对均方根偏差分别小于0.190%和0.266%。进一步将得到的二元交互参数导入流程模拟系统，对萃取单元模块进行计算。当萃取温度40℃、萃取级数5级、相比1：7.72时，甲基异丙基甲酮能将总酚12700 mg×L^-1，多元酚4250 mg×L^-1的含酚废水的酚浓度分别降低至300 mg×L^-1和299 mg×L^-1以下。

关键词: 甲基异丙基甲酮, 对苯二酚, 相平衡, 溶剂萃取, 模拟