Computational study on the structure II clathrate hydrate of methane and large guest molecules

Hydrogen Inter-Cage Hopping and Cage Occupancies inside Hydrogen Hydrate: Molecular-Dynamics Analysis

“…This has added to our understanding of clathrate hydrates' thermodynamic properties and their possibilities for energy stockpiling, especially of hydrogen. Indeed, these MD methodologies might be deployed to a greater degree in the coming decade, as what appears computationally 'heroic' today may turn out to be routinely available in the hydrate simulation network in the medium-term future [16][17][18]. During much of the 20 th century, it had been suspected that the molecular size of hydrogen was too small to confer appreciable thermodynamic stabilisation to clathrate hydrates [10,19], although more recent investigations in the past 20 years or so show that a large degree of H 2 (perhaps up to around 5 wt %, albeit with some uncertainty) can be accommodated in cubic structure II clathrate hydrates under higher-pressure conditions (i.e., at pressures of around 1 GPa and higher at ambient temperature conditions) [20,21].…”

Diffusive hydrogen inter-cage migration in hydrogen and hydrogen-tetrahydrofuran clathrate hydrates

“…Therefore, across a broader pressure range, each 5 12 cage may contain one, or possibly two, H 2 molecules, while each 5 12 6 4 cage may contain a single THF molecule or up to four H 2 molecules [4]. The extreme pressure needed for formation of pure hydrogen hydrate has been a limiting factor and has led to the study of mixed stabiliser-H 2 hydrates [8,9,10], in the hope that a stabilising compound will allow hydrate formation at lower pressures. Hydrates stabilised by THF have attracted interest in this respect as they have been reported to be stable at close to room temperature, and at much lower pressures than pure hydrogen-hydrate [4,5,8,11].…”

Natural Gas Hydrates

“…Erfan-Nia et al [146] have used molecular simulations to analyze the structure of hydrates formed from the methane+ethane mixture, showing that type I hydrates are formed in the whole composition range. Also, they used molecular simulations to show the methane storage capacity of structure II hydrates with the help of large guest molecules such as propane, i-butane, tetrahydrofuran etc [147].…”