Crystal Growth of Clathrate Hydrate at the Interface between Seawater and Hydrophobic-Guest Liquid: Effect of Elevated Salt Concentration
Crystal Growth of Clathrate Hydrate at the Interface between Seawater and Hydrophobic-Guest Liquid: Effect of Elevated Salt Concentration
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DOI：
10.1021/ie202785z
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发表时间：
2012-04-11
影响因子：
4.2
通讯作者：
Ohmura, Ryo
中科院分区：
文献类型：
--
作者：
Kishimoto, Masatoshi;Iijima, Satoshi;Ohmura, Ryo
本文报道了在氯化钠水溶液和客体液体界面上笼形水合物晶体生长和形态的目视观察。在质量分数为0.035 ~ 0.264的NaCl浓度范围内，水合物晶体的生长都是肉眼可见的。质量分数0.035对应于普通海水的质量分数，并且测试的盐浓度扩展到饱和水平，即，0.264.环戊烷被用作客体物质。观察到水合物晶体在环戊烷-NaCl溶液界面处的形成和生长。我们对单个水合物晶体进行了目视分析，并根据大气压下的Δ T-sub对晶体的形态进行了分类。结果发现，单个水合物晶体的尺寸随着Δ T-sub的增加而减小。结果表明，在给定的Δ T-sub下，任何NaCl浓度下的单个水合物晶体的形态大致相似。我们还测量了水合物膜传播的横向生长速率。水合物膜的生长速率随Δ T-sub的降低而降低，并且在给定的Δ T-sub下随NaCl浓度的增加而降低。
This paper reports the visual observations of the clathrate hydrate crystal growth and morphology at the interface of aqueous NaCl solutions and a guest-substance liquid. The hydrate crystal growth was visually characterized in the systems of a wide range of NaCl concentrations from 0.035 to 0.264 in mass fraction. The mass fraction 0.035 was corresponding to that of ordinary seawater, and the salt concentration tested was extended up to the saturation level, i.e., 0.264. Cyclopentane was used as the guest substance. Formation and growth of hydrate crystals at the cyclopentane-NaCl solution interface were observed. We visually analyzed the individual hydrate crystals and classified the morphology of the crystals according to Delta T-sub at atmospheric pressure. It was found that the size of the individual hydrate crystals decreased with increasing Delta T-sub. The results showed that the morphology of the individual hydrate crystals in any NaCl concentration is roughly similar at a given Delta T-sub. We also measured the lateral growth rates of the hydrate-film propagation. The hydrate film growth rate decreased with decreasing Delta T-sub in any of the systems and decreased with increasing concentration of NaCl at a given Delta T-sub.