Laboratory of Thermodynamics, Department of Biochemical and Chemical Engineering, TU Dortmund University, Emil-Figge Str. 70, 44277 Dortmund, Germany.
Molecules. 2023 Feb 13;28(4):1768. doi: 10.3390/molecules28041768.
The study of chemical reactions in multiple liquid phase systems is becoming more and more relevant in industry and academia. The ability to predict combined chemical and phase equilibria is interesting from a scientific point of view but is also crucial to design innovative separation processes. In this work, an algorithm to perform the combined chemical and liquid-liquid phase equilibrium calculation was implemented in the PC-SAFT framework in order to predict the thermodynamic equilibrium behavior of two multicomponent esterification systems. Esterification reactions involve hydrophobic reacting agents and water, which might cause liquid-liquid phase separation along the reaction coordinate, especially if long-chain alcoholic reactants are used. As test systems, the two quaternary esterification systems starting from the reactants acetic acid + 1-pentanol and from the reactants acetic acid + 1-hexanol were chosen. It is known that both quaternary systems exhibit composition regions of overlapped chemical and liquid-liquid equilibrium. To the best of our knowledge, this is the first time that PC-SAFT was used to calculate simultaneous chemical and liquid-liquid equilibria. All the binary subsystems were studied prior to evaluating the predictive capability of PC-SAFT toward the simultaneous chemical equilibria and phase equilibria. Overall, PC-SAFT proved its excellent capabilities toward predicting chemical equilibrium composition in the homogeneous composition range of the investigated systems as well as liquid-liquid phase behavior. This study highlights the potential of a physical sound model to perform thermodynamic-based modeling of chemical reacting systems undergoing liquid-liquid phase separation.
多液相体系中化学反应的研究在工业和学术界中变得越来越重要。从科学角度来看，预测组合化学和相平衡的能力很有趣，但对于设计创新的分离过程也至关重要。在这项工作中，为了预测两个多组分酯化系统的热力学平衡行为，在 PC-SAFT 框架中实现了一种用于进行组合化学和液-液相平衡计算的算法。酯化反应涉及疏水性反应剂和水，这可能会沿着反应坐标导致液-液相分离，特别是如果使用长链醇反应物。作为测试系统，选择了由反应物乙酸+1-戊醇和由反应物乙酸+1-己醇起始的两个季戊四醇酯化系统。已知这两个季戊四醇系统都表现出化学和液-液相平衡重叠的组成区域。据我们所知，这是首次使用 PC-SAFT 来计算同时的化学和液-液相平衡。在评估 PC-SAFT 对同时化学平衡和相平衡的预测能力之前，先研究了所有二元子系统。总体而言，PC-SAFT 证明了其在预测所研究系统的均匀组成范围内的化学平衡组成以及液-液相行为方面的出色能力。这项研究强调了物理合理模型在进行经历液-液相分离的化学反应系统的热力学建模方面的潜力。
