Insight into the Local Composition of the Wilson Equation at High Temperatures and Pressures through Molecular Simulations of Methanol–Water Mixtures
Insight into the Local Composition of the Wilson Equation at High Temperatures and Pressures through Molecular Simulations of Methanol–Water Mixtures
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通过甲醇-水混合物的分子模拟深入了解高温高压下威尔逊方程的局部组成
DOI：
10.1021/je400744j
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发表时间：
2014
影响因子：
--
通讯作者：
H. Inomata
中科院分区：
文献类型：
--
作者：
T. Ono;K. Horikawa;M. Ota;Y. Sato;H. Inomata
已知甲醇-水混合物在微观上是不均匀的，并且在环境条件下以及在更高的温度和压力下显示出非理想的性质。为了理解甲醇-水混合物的非理想性，在25 °C-0.1 MPa、300 °C-25 MPa和350 °C-25 MPa三种条件下，通过活度系数方程、Wilson方程和分子动力学（MD）模拟计算局部摩尔分数，研究了局部组成的行为。重新确定Wilson参数，以生成本研究中比较的参考值。选择局部摩尔分数与本体摩尔分数的偏差作为局部组成的指标。Wilson方程的偏差在所有组成中均为正值，且水的偏差幅度远大于甲醇的偏差幅度，这与温度和压力基本无关，完全得到分子动力学模拟结果的支持。MD模拟提供了局部摩尔分数偏差对分子间距离的依赖性，并表明Wilson局部摩尔分数中的近邻近似对应于径向分布函数中从第一谷到第二峰的距离范围。此外，通过MD模拟的局部摩尔分数的一般趋势是相似的，在环境和高温高压条件下，这表明甲醇-水混合物的Wilson方程的适用性，以高温高压条件下的局部摩尔分数。
Methanol–water mixtures are known to be microscopically inhomogeneous and show nonideal properties at ambient conditions and also at higher temperatures and pressures. To understand the nonideality of methanol–water mixtures, the behaviors of local compositions were studied through evaluating the local mole fractions by the well-known activity coefficient equation, Wilson equation, and by molecular dynamics (MD) simulation at three conditions: 25 °C–0.1 MPa, 300 °C–25 MPa, and 350 °C–25 MPa. The Wilson parameters were redetermined to generate the reference values for the comparison in this study. The deviation of local mole fraction from bulk mole fraction was selected as an indicator for local composition. The deviations by the Wilson equation were positive in all compositions, and its magnitude for water was much larger than that for methanol, which is principally independent of temperature and pressure and was completely supported by the results by MD simulation. The MD simulation provided the dependence of the local mole fraction deviation on the intermolecular distance and indicated that the immediate neighbor in the Wilson local mole fraction approximately corresponds to the distance range from first valley to second peak in the radial distribution function. In addition, the general trends of local mole fraction by MD simulation are similar at ambient and high temperature and pressure conditions, suggesting the applicability of the Wilson equation for methanol–water mixture to high temperature and pressure conditions in terms of representing the local mole fraction.
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DOI：
10.1023/a:1017506524963
发表时间：
2001
期刊：
影响因子：
--
作者：
D. Safarov;A. Shakhverdiev
通讯作者：
A. Shakhverdiev
DOI：
10.1252/kakoronbunshu1953.32.149
发表时间：
1968
期刊：
影响因子：
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作者：
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影响因子：
2.6
作者：
T. Honma;S. Kuzuhara;C. Liew;H. Inomata
通讯作者：
H. Inomata
通过密度测量和 MD 模拟研究亚临界和超临界状态下甲醇-水混合物的体积行为和溶液微观结构
影响因子：
2.6
作者：
Takumi Ono;S. Kobayashi;T. Hoshina;Yoshiyuki Sato;H. Inomata
通讯作者：
H. Inomata
DOI：
10.1021/ie50541a037
发表时间：
1955
期刊：
影响因子：
--
作者：
S. Green;R. E. Vener
通讯作者：
R. E. Vener