Energy Storage in Hydrates: Status, Recent Trends, and Future Prospects

Clathrate hydrates are non-stoichiometric, crystalline, caged compounds that have several pertinent applications including gas storage, CO2 capture/sequestration, gas separation, desalination, and cold energy storage. This review attempts to present the current status of hydrate based energy storage, focusing on storing energy rich gases like methane and hydrogen in hydrates. Gas storage in hydrates is an extremely safe, environmentally friendly, highly compact mode of storage and relatively cost-effective alternative compared to conventional gas storage methods. This review provides the status update of hydrate based gas storage technology to researchers and the scientific community. Along with recent trends in this domain, this work also discusses existing challenges and drafts future directions of research to resolve the impending challenges. In addition, different kinetic and thermodynamic promoters along with their role in influencing the kinetics of hydrate formation and energy (gas) storage capacities, various reactor designs employed for studying hydrate based energy storage, and patents in this domain are elucidated in the review. Challenges hindering the translation of these technologies to commercial scale along with economic perspectives and way forward for hydrate based energy storage are highlighted as well.