使用计算化学计算非随机性因子的几何方法
Pedro Velho1,2, Leonor R Barroca1,2, Eugénia A Macedo1,2
1LSRE-LCM-Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
Journal of chemical and engineering data
|October 17, 2024
概括
本研究介绍了Porto的方法,这是一种使用计算化学计算分子非随机性因子 (α) 的新方法. 这增强了像NRTL和UNIQUAC这样的热力学模型,以更好地预测混合物中的相位平衡.
科学领域:
- 热力学和物理化学热力学和物理化学
- 计算化学计算化学
- 化学工程是化学工程的重要组成部分.
背景情况:
- 非随机系数 (α) 对于热力学模型,如非随机双液体 (NRTL) 和通用准化学 (UNIQUAC) 非常重要,但很难准确估计.
- 固定的非随机性因素可以导致相位平衡相关性中的不准确性和收问题,特别是在复杂的混合物中.
研究的目的:
- 开发和应用一种新的几何方法 (Porto方法) 来计算特定组件的非随机性因子 (α).
- 评估特定组件的非随机性因素对液体-液体平衡 (LLE) 数据相关性NRTL和UNIQUAC模型的准确性的影响.
主要方法:
- 利用计算化学 (密度函数理论,DFT) 来优化分子能量并确定溶剂中的稳定配置.
- 使用自然键轨道 (NBO) 种群分析计算分子二极点时刻,以导出非随机性因子.
- 在NRTL和UNIQUAC模型中应用了特定组件的非随机性因子,用于对三元系统的LLE数据进行相关联.
主要成果:
- 通过Porto的方法成功计算了50个纯成分的非随机性因子.
- 15个三元系统的相关LLE数据与NRTL和UNIQUAC模型使用经典和组件特定的非随机性因子.
- 在经典和特定组件的非随机因子方法之间实现了可比的标准偏差,这表明模型适用性得到了改进.
结论:
- 波尔托的方法为估计非随机性因素提供了一种物理上有意义的方法,增强了过量自由吉布斯能量模型的应用.
- 这种方法代表了对非理想混合物的精确热力学建模的重大进步,包括含有电解质的混合物.
- 该研究通过改善热力学模型的物理基础,为更精确的相位平衡预测铺平了道路.
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