Performance Evaluation and Molecular Dynamics Simulation in the Liquid-Liquid Extraction Process of Low Transition Temperature Mixture +n-Hexane+1,2-Dichloroethane
Performance Evaluation and Molecular Dynamics Simulation in the Liquid-Liquid Extraction Process of Low Transition Temperature Mixture +n-Hexane+1,2-Dichloroethane
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DOI：
10.1016/j.molliq.2022.119913
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发表时间：
2022-07
影响因子：
6
通讯作者：
Wei Zhang;Xiaoyang Yi;Q. Yi;Lanyi Sun
中科院分区：
文献类型：
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作者：
Wei Zhang;Xiaoyang Yi;Q. Yi;Lanyi Sun
硫酸乙烯酯是一种新型电池添加剂，可以显著提高电池性能，但其生产过程中会产生大量正己烷+ 1,2-二氯乙烷（DCE）共沸混合物。本文以绿色高效的低温混合物（LTTMs）为溶剂，对正己烷+ DCE共沸体系的分离性能和机理进行了研究。首先，采用类导体筛选链段活度系数模型（cosmos - sac）研究了氢键给体和氢键受体的结构和组成对萃取性能的影响。在此基础上，结合实验筛选出3种萃取分离正己烷+ DCE的溶剂，分别为：盐酸三甲胺-乙酰丙酸1:2 （LTTM1）、四乙基氯化铵-乙酰丙酸1:2 （LTTM2）、四乙基氯化铵-丙酮酸1:2 （LTTM3）。随后，对正己烷+ DCE + LTTMs三元体系进行了液液平衡（LLE）实验，结果表明，在实验温度范围内低温有利于DCE的提取。然后，通过分子动力学模拟研究了LTTMs萃取分离正己烷+ DCE的微观机理。结果表明，lttm与DCE的相互作用远大于lttm与正己烷、正己烷与DCE的相互作用，这是lttm分离正己烷+ DCE的根本原因。最后，利用Aspen Plus模拟了正己烷+ DCE的连续分离过程，结果表明，lttm具有良好的萃取性能，正己烷和DCE的纯度分别可达到99.6 mol%和99.5 mol%。采用实验与模拟相结合的方法研究了lttm萃取分离正己烷+ DCE的可行性和微观机理，为正己烷+ DCE的分离提供了方法学参考。
Vinyl sulphate, a new battery additive, can significantly improve battery performance, but its production process generates a large amount ofn-hexane + 1,2-dichloroethane (DCE) azeotropic mixtures. In this paper, green and efficient Low Transition Temperature Mixtures (LTTMs) were used as solvents to explore their separation performance and mechanism of then-hexane + DCE azeotrope system. Firstly, the conductor-like screening model for segment activity coefficient (COSMO-SAC) model was used to investigate the effects of the structure and composition of the hydrogen bond donors and hydrogen bond acceptors on the extraction performance. On this basis, three LTTMs were screened out as solvents for the extraction and separation ofn-hexane + DCE by combining experiments, which were trimethylamine hydrochloride-levulinic acid 1:2 (LTTM1), tetraethylammonium chloride-levulinic acid 1:2 (LTTM2), tetraethylammonium chloride-pyruvic acid 1:2 (LTTM3). Afterward, Liquid–liquid equilibrium (LLE) experiments were carried out for the ternary system ofn-hexane + DCE + LTTMs, and the results showed that the extraction of DCE was favored by low temperatures in the experimental temperature range. Then, molecular dynamics simulation was used to investigate the microscopic mechanism of the extraction and separation ofn-hexane + DCE by LTTMs. The results showed that the interaction between LTTMs and DCE was much larger than that between LTTMs andn-hexane,n-hexane and DCE, which was the fundamental reason for the separation ofn-hexane + DCE by LTTMs. Finally, the continuous separation process ofn-hexane + DCE was simulated using Aspen Plus, and the results showed that LTTMs had good extraction performance and the purity ofn-hexane and DCE products could reach 99.6 mol% and 99.5 mol%, respectively. The feasibility and microscopic mechanism of the extraction and separation ofn-hexane + DCE by LTTMs were investigated using a combination of experiments and simulations, which provided a methodological reference for the separation ofn-hexane + DCE.