Molecular simulation study on the evolution process of hydrate residual structures into hydrate  

作　　者：Liwei Cheng Yunfei Li Jinlong Cui Huibo Qin Fulong Ning Bei Liu Guangjin Chen 

机构地区：[1]Faculty of Engineering,China University of Geosciences,Wuhan 430074,China [2]State Key Laboratory of Heavy Oil Processing,China University of Petroleum,Beijing 102249,China [3]College of Science,Nanchang Institute of Technology,Nanchang 330099,China [4]School of Chemical Engineering,Guangdong University of Petrochemical Technology,Maoming 525000,China [5]National Center for International Research on Deep Earth Drilling and Resource Development,China University of Geosciences(Wuhan),Wuhan 430074,China

出　　处：《Chinese Journal of Chemical Engineering》2024年第5期79-91,共13页中国化学工程学报（英文版）

基　　金：Financial support from the National Natural Science Foundation of China(22208329,22178378,22127812,21908116 and U19B2005);Jiangxi Provincial Natural Science Foundation of China(20232BAB213044)。

摘　　要：The clathrate hydrate memory effect is a fascinating phenomenon with potential applications in carbon capture,utilization and storage(CCUS),gas separation,and gas storage as it can accelerate the secondary formation of clathrate hydrate.However,the underlying mechanism of this effect remains unclear.To gain a better understanding of the mechanism,we conducted molecular dynamic simulations to simulate the initial formation and reformation processes of methane hydrate.In this work,we showed the evolution process of hydrate residual structures into hydrate cages.The simulation results indicate that the residual structures are closely related to the existence of hydrate memory effect,and the higher the contribution of hydrate dissociated water to the hydrate nucleation process,the faster the hydrate nucleation.After hydrate dissociation,the locally ordered structures still exist after hydrate dissociation and can promote the formation of cluster structures,thus accelerating hydrate nucleation.Additionally,the nucleation process of hydrate and the formation process of clusters are inseparable.The size of clusters composed of cup-cage structures is critical for hydrate nucleation.The residence time at high temperature after hydrate decomposition will affect the strength of the hydrate memory effect.Our simulation results provide microscopic insights into the occurrence of the hydrate memory effect and shed light on the hydrate reformation process at the molecular scale.

关 键 词：Memory effect Molecular simulation Hydrate reformation Residual structures 

分 类 号：TE37[石油与天然气工程—油气田开发工程]