Formation of the structure-Ⅱgas hydrate from low-concentration propane mixed with methane  

作　　者：Sanya Du Xiaomin Han Wenjiu Cai Jinlong Zhu Xiaobai Ma Songbai Han Dongfeng Chen Yusheng Zhao Hui Li Hailong Lu Xiaohui Yu 

机构地区：[1]Beijing Advanced Innovation Center for Soft Matter Science and Engineering,Beijing University of Chemical Technology,Beijing 100029,China [2]National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [3]College of Engineering,Peking University,Beijing 100871,China [4]Beijing International Center for Gas Hydrate,School of Earth and Space Sciences,Peking University,Beijing 100871,China [5]Department of Physics,Southern University of Science and Technology(SUSTech),Shenzhen 518055,China [6]Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 511458,China [7]Department of Nuclear Physics,China Institute of Atomic Energy,Beijing 102413,China [8]Academy for Advanced Interdisciplinary Studies,Southern University of Science and Technology(SUSTech),Shenzhen 518055,China [9]Songshan Lake Materials Laboratory,Dongguan 523808,China

出　　处：《Chinese Journal of Chemical Engineering》2023年第6期306-314,共9页中国化学工程学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(2016YFA0401503 and 2018YFA0305700);the National Natural Science Foundation of China(11575288,91934303,21935001 and 11775011);the Strategic Priority Research Program;Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(XDB33000000,XDB25000000 and QYZDBSSW-SLH013);the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y202003);the China Geological Survey(DD20190234);the Scientific Instrument Developing Project(ZDKYYQ20170001)of the Chinese Academy of Sciences。

摘　　要：It has been recognized that a small amount of propane mixed with methane can change greatly in not only the thermodynamics but also the structural properties of gas hydrate.However,its mechanism is still not well understood yet.In this research,structure-Ⅱ(sⅡ)hydrate is synthesized using a methanepropane gas mixture with an initial mole ratio of 99:1,and it is found that large(5~(12)6~4)cages are cooccupied by multiple gases based on the rigid structure analysis of neutron diffraction data.The first principles calculation and molecular dynamics simulation are conducted to uncover the molecular mechanism for sⅡmethane-propane hydrate formation,revealing that the presence of propane inhibits the formation of structure-Ⅰ(sⅠ)hydrate but promotes sⅡhydrate formation.The results help to understand the accumulation mechanism of natural gas hydrate and benefit to optimize the condition for gas storage and transportation in hydrate form.

关 键 词：Multiple guest molecules CLATHRATES Neutron powder diffraction Structural transformation Molecular mechanism 

分 类 号：TE64[石油与天然气工程—油气加工工程]