Gas hydrate technology and emerging applications: A comprehensive review of energy, environmental, and industrial prospects

Gas hydrates are crystalline compounds composed of a hydrogen-bonded water structure that traps small molecules under low-temperature and high-pressure conditions. Due to their high storage capacities, controllable stability, and distinct phase behavior, these materials have emerged as promising alternatives for a wide range of engineering and environmental applications. In moderate conditions, their remarkable self-preservation behavior makes them an interesting companion or an alternative to conventional methods such as LNG and CNG. Additionally, hydrate formation can be used to selectively separate gases. Because different gases trapped in hydrate cages have different molecular sizes, this technique can capture specific gas molecules more effectively than other methods. The selectivity of hydrates enables them to capture and purify greenhouse gases, industrial gases, and light hydrocarbons, and even more complex mixtures, such as ionic liquid systems or gas mixtures with very similar boiling points. Compared to conventional separation approaches, gas hydrate-based processes use water as the primary component, thereby reducing chemical and energy consumption. The purification of water produced by hydrate dissociation is used in a variety of environmental applications, such as seawater desalination and wastewater treatment that contains dyes, salts, and organic impurities. In the food and process industries, gas hydrate formation offers non-thermal concentration, protection of sensitive compounds, and control of frozen texture. Moreover, gas hydrates help suppress fires, enabling them to be extinguished quickly and efficiently due to their extensive heat absorption and rapid gas release properties. As a result of their high latent heat, hydrate slurries have been investigated for use in cold storage and air conditioners as cold storage media. Although hydrate technologies are widely applicable, the kinetics of hydrate formation, pressure and cooling requirements, continuous reactor operation, and scale-up remain challenges. To overcome these issues, advances in promoters, reactor designs, and process optimization are necessary to address these limitations. In addition, this review critically evaluates the technical, environmental, economic, and safety risks associated with hydrate-based technologies, highlighting key barriers to large-scale implementation and long-term sustainability. Current research shows that gas hydrate science is advancing toward new technologies that are not only more reliable and scalable but also better aligned with environmental and industrial needs. Rather than considering hydrates simply as blockage materials, the field is increasingly approaching them as an effective phase-transition mechanism with the potential of offering diverse process applications. Additionally, this review presents recent progress across major hydrate-based applications, including energy production, gas storage and transport, gas mixtures and greenhouse gas separation, water remediation, food processing, thermal management, and fire suppression. These newly emerging applications reflect the need for an improved understanding of the formation and dissociation mechanisms of gas hydrates.