Predictions of water/oil interfacial tension at elevated temperatures and pressures: A molecular dynamics simulation study with biomolecular force fields
Predictions of water/oil interfacial tension at elevated temperatures and pressures: A molecular dynamics simulation study with biomolecular force fields
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DOI：
10.1016/j.fluid.2017.05.004
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发表时间：
2018-11-25
影响因子：
2.6
通讯作者：
Economou, Ioannis G.
中科院分区：
文献类型：
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作者：
Papavasileiou, Konstantinos D.;Moultos, Othonas A.;Economou, Ioannis G.
水/油混合物的界面性质是石油和天然气以及化学工业的重要兴趣主题，因为它们需要执行过程计算。然而，在高温和高压下的报告数据很少。本研究的重点是模拟水与i）甲苯（水/甲苯）、ii）正十二烷（水/正十二烷）和iii）50：50 wt %甲苯：正十二烷混合物（水/甲苯/正十二烷）的混合物在1.83 MPa和383.15至443.15 K的温度下的界面张力（IFT）。采用主要为生物分子系统开发的原子分子模型的分子动力学（MD）模拟。在进行的模拟中，水模型的影响和通过引入二元相互作用参数kid的原子间相互作用的缩放进行了评估，以准确再现实验数据。TIP 4P/2005、SPC/E和TIP 3 P水模型分别与甲苯和正十二烷的GAFF和Lipid 14力场相结合，再加上适当的二元相互作用参数k（ij），用于碳与氧原子的相互作用，在二元混合物的情况下，可以得到准确的结果。对于水/甲苯/正十二烷的混合物，所有的力场组合测试导致高估IFT值的整个范围内的状态点检查。我们的模拟表明，这些广泛使用的力场，来自世界上的生物分子模拟，是合适的候选人在二元水/油混合物的研究。然而，引入的k（ij）标度参数是不够的，以允许准确再现实验IFT数据的三元水/油/油混合物。(C)2017 Elsevier B. V.版权所有。
The interfacial properties of water/oil mixtures is a topic of significant interest for the oil and gas and chemical industry, as they are required for performing process calculations. However, the reported data at high temperatures and pressures are scarce. The present study focuses on simulating the interfacial tension (IFT) of mixtures of water with i) toluene (water/toluene), ii) n-dodecane (water/n-dodecane) and iii) a 50:50 % wt toluene:n-dodecane mixture (water/toluene/n-dodecane), at 1.83 MPa and temperatures ranging from 383.15 to 443.15 K. Molecular Dynamics (MD) simulations with atomistic molecular models, developed primarily for biomolecular systems were employed. In the simulations performed, the effects of the water model and the scaling of interatomic interactions by introducing a binary interaction parameter, kid, were assessed for the accurate reproduction of experimental data. The combination of the TIP4P/2005, SPC/E and TIP3P water models with the GAFF and Lipid14 force fields for toluene and n-dodecane respectively, coupled with appropriate binary interaction parameters, k(ij), for the interaction of carbon with oxygen atoms were found to yield accurate results in the case of binary mixtures. For the water/toluene/n-dodecane mixture, all force field combinations tested resulted in overestimated IFT values for the whole range of state points examined. Our simulations show that these widely used force fields, originating from the world of biomolecular simulations, are suitable candidates in the study of binary water/oil mixtures. Nevertheless, the introduction of the k(ij) scaling parameter is not sufficient to allow the accurate reproduction of experimental IFT data for ternary water/oil/oil mixtures. (C) 2017 Elsevier B.V. All rights reserved.