Perspectives on facilitating natural gas and hydrogen storage in clathrate hydrates under a static system

The rising demand for natural gas (NG) and hydrogen, due to their lower carbon footprint and role in storing surplus renewable energy, has highlighted the focus on developing advanced storage technologies. Traditional methods like liquefaction and compression face high energy and safety challenges, prompting the exploration of new solutions. Among these, hydrate-based gas storage stands out for its environmental benefits, using clathrate hydrates to store gas with low energy consumption and carbon emissions. Furthermore, the composition of hydrates, predominantly water (∼85%), and their lack of by-products during repetitive storage–release cycles firmly establish them as environmentally friendly gas storage media. However, kinetic challenges such as stochastic nucleation, limitations in mass and heat transfer, and thermodynamic barriers arising from harsh hydrate formation conditions have hindered the practical application of hydrates. While mechanical methods to improve hydrate formation exist, their use significantly increases the demand for electrical energy. Therefore, developing methods for gas hydrate formation under static conditions is crucial for utilizing this material as a safe and green gas storage medium. This review examines theoretical studies and experimental efforts to enhance hydrate formation kinetics in static systems without additional mechanical methods. Thermodynamic hydrate promoters to increase the driving forces for hydrate formation under mild conditions, surface-modified materials to increase nucleation probabilities for shorter induction times, and porous materials to provide pathways for mass and heat transfer have been widely investigated. The discussion addresses the direction and necessary efforts for utilizing hydrate-based gas storage as a next-generation green technology.