超临界或高压CO_2中无限稀释扩散系数的模拟

Molecular Dynamics Simulation of Infinite Dilute Diffusion Coefficients of Solute in Supercritical CO_2

采用分子动力学模拟的方法对超临界二氧化碳的自扩散系数及甲醇和乙醇在超临界二氧化碳中的无限稀释扩散系数进行了模拟计算。结果表明,分子动力学模拟方法可较准确地反映二氧化碳的扩散性质,计算无限稀释扩散系数取得了与实验值较吻合的结果。采用这种新方法可以准确有效的地预测超临界体系的扩散性质,将会更加广泛应用于工程设计,因此分子动力学模拟作为先进的研究手段会得到越来越广泛的应用。

The self-diffusion coefficients of supercritical carbon dioxide and infinite dilute diffusion coefficients of methanol and ethanol in supercritical carbon dioxide were investigated by molecular dynamics simulation. It was shown that the spherical model could be used to characterize the diffusion property of supercritical carbon dioxide correctly. The calculation results of infinite dilute diffusion coefficients showed good agreements with experimental values. This new method can be used to predict the diffusion property of supercritical systems effectively and be used for engineering design extensively. Therefore, as an advanced research methods, molecular dynamics simulation will be used more widely.