| 초록 |
The natural gas hydrates (NGHs) are crystalline inclusion compounds that form at low temperature and high pressure conditions and are regarded as our future clean energy source. Some NGH samples recovered from deep ocean sediments were revealed to contain large molecule guest substances (LMGSs) and thus, to have structure H (sH) as well as structure I (sI), structure II (sII). However, the thermodynamic phase behavior and structural features of complex systems containing LMGSs and gas mixtures have not been well understood. In this study, neohexane and methylcyclopentane were selected as LMGSs. The four-phase (H-Lw-LLMGS-V) equilibria of CH4 + C3H8 + LMGS and CH4 + C2H6 + LMGS + water mixtures were measured to determine the accurate phase behavior of the systems. The structure and guest distributions of complicated hydrate systems were analyzed using 13C NMR and PXRD. It was found that neither C2H6 nor C3H8 was not captured in sH cages whereas LMGSs were occupied in the larges cages of sH. |
