Gas hydrates have received considerable attention due to their important role in flow assurance for the oil and gas industry, their extensive natural occurrence on Earth and extraterrestrial planets, and their significant applications in sustainable technologies including but not limited to gas and energy storage, gas separation, and water desalination Given not only their inherent structural flexibility depending on the type of guest gas molecules and formation conditions, but also the synthetic effects of a wide range of chemical additives on their properties, these variabilities could be exploited to optimise the role of gas hydrates This includes increasing their industrial applications, understanding and utilising their role in Nature, identifying potential methods for safely extracting natural gases stored in naturally occurring hydrates within the Earth, and for developing green technologies This review summarizes the different properties of gas hydrates as well as their formation and dissociation kinetics and then reviews the fast-growing literature reporting their role and applications in the aforementioned fields, mainly concentrating on advances during the last decade Challenges, limitations, and future perspectives of each field are briefly discussed The overall objective of this review is to provide readers with an extensive overview of gas hydrates that we hope will stimulate further work on this riveting field

Gas hydrates in sustainable chemistry

Pore-scale modeling of flow in particle packs containing grain-coating and pore-filling hydrates: Verification of a Kozeny–Carman-based permeability reduction model

The possible existence of a vast amount of methane hydrate around islands has attracted attention as the largest potential hydrocarbon re source in Japan. At the same time, several production methods have been considered to extract the gas from the hydrate zone. Although it is known that the hydrates pose significant obstacles to drilling and production operations, there is at present only limited knowledge on t he mechanical behavior of hydrate-rich zones, which is necessary to understand the stability around the site. In order to know the properties of methane hydrate and/or its sand mixtures, a series of tests was carried out on artificial methane hydrate-sand mixtures, using low temperature and a newly developed high confining pressure triaxial compression technique. The sediments used in the mixture were o btained from a 207.75m sea bottom core from the Nankai Trough, located 1152.75m below sea level. The specimens used were prepared by compressing a mixture of artificial methane hydrate and the sediments with a volume ratio of sediments to the whole of specimen. On th e basis of these experimental results, the factors affecting mechanical properties of the hydrate and sediment mixtures are discussed. It is very essential to collect more data on the properties of methane hydrate and/or sedimentation (soil) mixture to understand the stability of a ny attempt at methane hydrate production.

Basic research on the mechanical behavior of methane hydrate-sediments mixture

Microstructure Evolution of Hydrate-Bearing Sands During Thermal Dissociation and Ensued Impacts on the Mechanical and Seepage Characteristics

Natural gas hydrate (NGH) is considered one of the most promising future energy sources because of its considerable reserves and high energy density, which could meet the growing global energy dema...

Mechanical Characteristics of Hydrate-Bearing Sediment: A Review

Rate effect on the stress-strain relations of synthetic carbon dioxide hydrate-bearing sand and dissociation tests by thermal stimulation

A new evaluation index for reliquefaction resistance of Toyoura sand

It is well known that the methane hydrate dissociation process may lead to unstable behavior such as large ground deformations, uncontrollable gas production, etc. A linear instability analysis was performed in order to investigate which variables have a significant effect on the onset of the instability behavior of methane hydrate-bearing soils subjected to dissociation. In the analysis a simplified viscoplastic constitutive equation is used for the soil sediment. The stability analysis shows that the onset of instability of the material system mainly depends on the strain hardening-softening parameter, the degree of strain, and the permeability for water and gas. Then, we conducted a numerical analysis of gas hydrate-bearing soil considering hydrate dissociation in order to investigate the effect of the parameters on the system. The simulation method used in the present study can describe the chemo-thermo-mechanically coupled behaviors such as phase changes from hydrates to water and gas, temperature changes and ground deformation. From the numerical results, we found that basically the larger the permeability for water and gas is, the more stable the simulation results are. These results are consistent with those obtained from the linear stability analysis.

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Stability Analysis of Methane Hydrate-Bearing Soils Considering Dissociation

Undrained Triaxial Compression Tests on Artificial CO2-hydrate-bearing Sand Specimens

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Hiromasa Iwai

Papers

Rate effect on the stress-strain relations of synthetic carbon dioxide hydrate-bearing sand and dissociation tests by thermal stimulation

A new evaluation index for reliquefaction resistance of Toyoura sand

Stability Analysis of Methane Hydrate-Bearing Soils Considering Dissociation

Undrained Triaxial Compression Tests on Artificial CO2-hydrate-bearing Sand Specimens

Behavior of Gas Hydrate-Bearing Soils during Dissociation and its Simulation