Microscopic measurements on the decomposition behaviour of methane hydrates formed in natural sands

doi:10.1039/c9ra01611b

	Microscopic measurements on the decomposition behaviour of methane hydrates formed in natural sands
	Wen, Long 1,2,3; Zhou, Xuebing 1,2; Liang, Deqing 1,2
刊名	RSC ADVANCES
	2019
卷号	9 期号:26 页码:14727-14735
ISSN号	2046-2069
DOI	10.1039/c9ra01611b
通讯作者	Liang, Deqing(liangdq@ms.giec.ac.cn)
英文摘要	In this work, the decomposition behaviour of methane hydrate in porous media was investigated microscopically using powder X-ray diffraction, cryogenic scanning electron microscopy and in situ Raman spectroscopy. The effect of grain sizes on the decomposition of methane hydrate was measured. The results showed that bulk hydrates could exist stably at 223 K and atmospheric pressure because of the self-preservation effect. However, hydrate formed in sands was relatively easier to decompose because it had a higher equilibrium pressure compared with bulk hydrate at the same temperature. In this case, there would be a higher decomposition driving force. Interestingly, the complete decomposition time for hydrate formed in sands did not decrease with the decrease in particle size. The shortest decomposition time was observed for the sands with the particle size range of 38-55 m, which was less than 30 minutes. Moreover methane hydrate was found to decompose faster in the porous medium containing 3.5 wt% NaCl, which suggested that there was almost no self-preservation effect. In situ Raman measurements showed that the integrated intensity ratio of methane in large and small cages (A(L)/A(S)) did not change during the decomposition process, suggesting that the methane hydrate crystal units decomposed as an entity in sands. This study provided important data as a basis for drilling fluid technology in hydrate mining.
资助项目	National Natural Science Foundation of China[41603062] ; National Key Research and Development Plan of China[2016YFC0304002]
WOS关键词	MOLECULAR-DYNAMICS SIMULATIONS ; STRATIGRAPHIC TEST WELL ; CARBON-DIOXIDE ; NUMERICAL-ANALYSIS ; PARTICLE SIZES ; POROUS-MEDIA ; DISSOCIATION ; PERMEABILITY ; SEDIMENTS ; CORES
WOS研究方向	Chemistry
语种	英语
出版者	ROYAL SOC CHEMISTRY
WOS记录号	WOS:000468641300019
资助机构	National Natural Science Foundation of China ; National Key Research and Development Plan of China
内容类型	期刊论文
源URL	[http://ir.giec.ac.cn/handle/344007/25190]
专题	中国科学院广州能源研究所
通讯作者	Liang, Deqing
作者单位	1.Chinese Acad Sci, CAS Key Lab Gas Hydrate, Guangzhou Inst Energy Convers, Guangzhou Ctr Gas Hydrate Res, Guangzhou 510640, Guangdong, Peoples R China 2.Guangdong Prov Key Lab New & Renewable Energy Res, Guangzhou 510640, Guangdong, Peoples R China 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Wen, Long,Zhou, Xuebing,Liang, Deqing. Microscopic measurements on the decomposition behaviour of methane hydrates formed in natural sands[J]. RSC ADVANCES,2019,9(26):14727-14735.
APA	Wen, Long,Zhou, Xuebing,&Liang, Deqing.(2019).Microscopic measurements on the decomposition behaviour of methane hydrates formed in natural sands.RSC ADVANCES,9(26),14727-14735.
MLA	Wen, Long,et al."Microscopic measurements on the decomposition behaviour of methane hydrates formed in natural sands".RSC ADVANCES 9.26(2019):14727-14735.