Carbon Dioxide Sequestration via Gas Hydrates: A Potential Pathway toward Decarbonization

TLDR

Climate change is driven mainly by rising atmospheric CO₂, and CO₂ hydrate offers a dense, stable, low‑flow‑perturbation option for long‑term sequestration. This review surveys CO₂ sequestration pathways, focusing on clathrate hydrates, and summarizes current research while outlining key challenges and prospects. The review examines biotic and abiotic CO₂ sequestration, especially clathrate hydrate routes, evaluating storage in seawater, seabed sediments, permafrost, CO₂–CH₄ exchange in methane hydrate reservoirs, and depleted gas fields, and analyzes their technical feasibility and storage capacity. Economic, scale‑up, and comparative attractiveness issues are discussed but are not the main focus of this work.

Abstract

Climate change is known to be dominantly caused by the increased concentration of greenhouse gases in the atmosphere, in particular CO2. To prevent excessive accumulation of CO2 in the atmosphere and the perturbation of natural carbon cycles, carbon capture and sequestration (CCS) is urgently needed. In this review, a brief overview is provided for both biotic and abiotic CO2 sequestration pathways. Special focus is given to sequestration approaches pertaining to clathrate hydrates. CO2 hydrate, a solid compound made of molecular CO2 enclathrated in crystalline lattices formed by water molecules, is an attractive option for long-term CO2 sequestration due to its higher density than seawater, stability below moderate oceanic/permafrost depths, low susceptibility to fluid flow perturbation when formed in sediments. This review compiles and summarizes the research efforts made on CO2 sequestration as hydrates. Various approaches of CO2 sequestration via gas hydrates are discussed, including storage in seawater, sediments under the sea floor, permafrost regions, methane hydrate reservoirs via CO2–CH4 exchange, and depleted gas fields. The technical feasibility and potential storage capacity of these approaches are analyzed. Finally, the key scientific challenges and prospects are identified and highlighted. Issues related to economics, scale-up, and relative attractiveness versus non-hydrate methods are touched upon but are not the focus of this work.