Abstract

In the presented work we studied the process of nucleation and growth of methane and propane gas hydrate from a homogeneous solution by means of molecular dynamics. The aim is to assess the effect of hydrate seed on the growth rate and structure of the resulting hydrate in the presence of sea salt. This process was characterized via calculation of the number of long-lived hydrogen bonds and amount of hydrate and hydrate-like cavities, as well as the order parameter of the intermolecular torsion angles. It is shown that the kinetics of hydrate formation do not differ much in the cases of pure water and seawater. A seed crystal of hydrate on the contrary, not only increases the hydrate growth rate, but also makes the resulting structure more consistent with the cubic structure II hydrate.

中文翻译：

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用分子动力学方法研究水合物种子和海盐存在下甲烷+丙烷水合物形成的动力学

摘要

在目前的工作中，我们通过分子动力学研究了均相溶液中甲烷和丙烷气体水合物的成核和生长过程。目的是评估在海盐存在下水合物种子对所得水合物的生长速率和结构的影响。通过计算长寿命氢键的数量、水合物和类水合物空腔的数量以及分子间扭转角的有序参数来表征该过程。结果表明，在纯水和海水的情况下，水合物形成的动力学没有太大差异。相反，水合物的晶种不仅提高了水合物的生长速率，而且使所得结构与立方结构II水合物更加一致。