Abstract:

Hydrate-based technology has great potentials in the fields of gas separation, gas storage, seawater desalination, cold storage and so on. The investigations of hydrate growth behaviors and hydrate morphology characteristics are necessary for the increase of hydrate gas storage capacity, the reduction of the risk of natural gas hydrate exploitation and the prevention of the pipe blockage caused by hydrate. This paper systematically reviews the researches of hydrate morphology from three aspects which are classified based on the size of hydrate: the hydrate lattice structure at nano scale, the hydrate crystal morphology at millimeter scale and the hydrate growth morphology at centimeter scale. This paper summarizes the lattice structures of the different hydrates formed by different guest molecules. This paper summarizes the effects of supercooling and liquid phase composition on the crystal morphology of clathrate hydrate and semi-clathrate hydrate. The growth behavior and the effects of the influential factors on hydrate growth morphology are introduced from four aspects: the heat transfer at the metal surface, the mass transfer at the interfaces between different phases, the effect of crystal nuclei and the effects of different promoters. This paper summarizes the promotion of the studies on hydrate morphology that lay a foundation for industrial application of hydrate-based technology, and provides a guidance for the further study on hydrate morphology.

Key words: hydrate, morphology, crystallization, semi-clathrate hydrate, promoters, surfactants

摘要：

水合物技术在气体分离、气体储存、海水淡化、蓄冷等领域有巨大的应用潜力。研究水合物的生长方式和形态特征在提高水合物储气量、降低水合物开采风险和防止水合物管道堵塞等方面有重要意义。本文从分子尺度的水合物晶格结构、毫米尺度的水合物晶体形态学和厘米尺度的水合物宏观生长形态学三个方面系统回顾了水合物形态学研究进展：总结了不同客体分子生成的不同类型水合物的不同晶格结构；从笼型水合物和半笼型水合物两个方面，阐述了过冷度、液相组成对水合物晶体形态学的影响；从金属表面传热、相界面传质、晶核加入以及促进剂的使用四个方面，介绍了水合物生长形态学的生长方式及其机理。本文总结了形态学研究对水合物技术工业化应用的积极作用并为水合物形态学研究的进一步发展提供参考。

关键词: 水合物, 形态学, 结晶, 半笼型水合物, 促进剂, 表面活性剂