Phase transformation of methane hydrate under high pressure.
In situ Raman spectroscopy is employed to study the phase behavior of methane hydrate at high pressure. The structure 1 of methane hydrate can be maintained up to 950 MPa at 299 K. The transformation of structure I<-->structure H+water+CH4 occurs at 880 MPa and 323 K. The structure H of methane hydrate, however, decomposes to methane and water at 960 MPa and 348 K. The initiation mechanism of methane hydrate sI is also discussed.
Sun
Qiang
Q
School of Earth and Space Science, Peking University, Peking 100871, China.
Duan
Ti-Yu
TY
Zheng
Hai-Fei
HF
Ji
Jian-Qing
JQ
Wu
Xiang-Yang
XY