Jitendra Sangwai

Subsea sequestration retains a huge potential in terms of the long-term viability of stable CO2 storage and, therefore, can contribute to global carbon neutrality by addressing global warming challenges. However, macroscopic parameters such as salinity, porosity, sedimentary types, and additives play a vital role in tapping the fullest potential of subsea CO2 sequestration. This aspect offers a wide range of opportunities for discussion and will open new avenues for future development. Therefore, there is a wide scope for discussions in this area, which will lead to new technological innovations in the future. CO2 sequestration in subsea sediments in solid hydrate form is discussed in terms of interaction chemistry and macroscopic environmental effects on pore-scale hydrate formation and growth. This Perspective presents insights related to CO2 hydrate formation and its long-term stability with relevance to porous media, CO2-sedimentary interactions, the effect of additives, and possible cost estimates for large-scale CO2 storage in oceans. Insights into hydrate formation behavior and the effect of physicochemical parameters (interfacial tension, water saturation, organic matter, salinity, and the chemical nature of the sediments) have been additionally outlined. Light is shed on the economics of transportation and injection using cost estimates from the literature along with the challenges and outlook associated with the current technologies. The chemical interactions between CO2 and hydrate-bearing sediments, additives, and marine environments would aid in understanding hydrate formation in subsea sediments.