Unraveling Adhesion Strength between Gas Hydrate and Solid Surfaces

Abstract

Natural gas hydrate is a promising future energy source, but it also poses a huge threat to oil and gas production due to its ability to deposit within and block pipelines. Understanding the atomistic mechanisms of adhesion between the hydrate and solid surfaces and elucidating its underlying key determining factors can shed light on the fundamentals of novel antihydrate materials design. In this study, large-scale molecular simulations are employed to investigate the hydrate adhesion on solid surfaces, especially with focuses on the atomistic structures of intermediate layer and their influences on the adhesion. The results show that the structure of the intermediate layer formed between hydrate and solid surface is a competitive equilibrium of induced growth from both sides, and is regulated by the content of guest molecules. By comparing the fracture behaviors of the hydrate–solid surface system with different intermediate structures, it is found that both the lattice areal density of water structure and the adsorption of guest molecules on the interface together determine the adhesion strength. Based on the analysis of the adhesion strength distribution, we have also revealed the origins of the drastic difference in adhesion among different water structures such as ice and hydrate. Our simulation indicates that ice-adhesion strength is approximately five times that of lowest hydrate adhesion strength. This finding is surprisingly consistent with the available experimental results.

Anti-gas hydrate surfaces: perspectives, progress and prospects

“…11b, have been built for exploring hydrate adhesion. 172 By applying a tensile pulling force on the hydrate, the detaching stress σ d was taken as the reference of hydrate-adhesion strength, as ( F max _ pulling is the first force peak value in the force profile, A is the hydrate contact area). Given the sufficient computing power, surface parameters such as hydrophobicity, roughness, and interfacial lubricant layers can be gauged for their contribution to hydrate adhesion, similar to the studies performed for ice adhesion.…”

Molecular Insights into the Dual Promotion–Inhibition Effects of NaCl at Various Concentrations on the CO2 Hydrate Growth: A Molecular Simulation Study

“…The emissions of CO 2 have increased by about 90% since 1970, and the excessive release of CO 2 causes a serious greenhouse effect. − Gas hydrates are ice-like solids formed by the cage-like structure constructed by water molecules and the trapped nonpolar gas molecules at appropriate temperature and pressure conditions. − The CO 2 hydrates, possessing great CO 2 storage capacity, can be stored in marine environments at medium to deeper depths . Compared to conventional geological storage of CO 2 , storing CO 2 in the form of hydrates in the ocean has a larger reserve, which may be a potential way to mitigate global warming. − …”

Can Aluminum Cations Promote Nucleation for THF Hydrate Growth?

“…Clathrate hydrates (hereafter hydrates) are a specific category of clathrates, where hosts are hydrogen-bonded with water molecules . The hydrate studies are essential for several technological applications such as gas storage and transportation, water desalination, CO 2 sequestration, and prevention of pipeline plugging. − Understanding hydrate formation thermodynamics and kinetics is key to the development of hydrate-based technologies. The stable thermodynamic conditions of hydrates are primarily dependent on the type of guest molecules and the presence of external additives. ,, The nucleation kinetics and propagation of the hydrate front dominate gas hydrate formation kinetics.…”