Basalt Formations - CCUS Terms

Description:
Basalt formations are igneous rock layers rich in iron and magnesium, formed from the rapid cooling of basaltic lava. In the context of Carbon Capture, Utilization, and Storage (CCUS), these formations are used for the permanent sequestration of carbon dioxide (CO2) through a process called mineral carbonation.

Explanation:
In the CCUS framework, basalt formations play a crucial role in the long-term storage of captured CO2. Here’s how it works and fits into the broader CCUS strategy:

• Carbon Capture. While basalt formations do not directly participate in the carbon capture process, they are integral to the post-capture phase, where captured CO2 is prepared for storage.
• Utilization. Though primarily used for storage, the process of CO2 mineralization in basalt can be considered a form of utilization as it transforms CO2 into stable mineral compounds. These reactions not only sequester CO2 but also produce secondary minerals that may have long-term environmental benefits.
• Storage. The key role of basalt formations in CCUS is to store CO2 through a process called in situ mineral carbonation. CO2 is injected into the basalt formations where it reacts with calcium, magnesium, and iron-rich silicate minerals to form carbonate minerals like calcite and magnesite. This reaction effectively turns the gaseous CO2 into solid rock, permanently trapping it and preventing it from re-entering the atmosphere.

Advantages:
Using basalt formations for CO₂ storage offers several advantages: it ensures permanent sequestration through mineral carbonation, significantly reducing the risk of leakage; the global abundance of basalt formations provides numerous potential storage sites; and the process utilizes natural geochemical reactions, enhancing the environmental compatibility of the storage method.

Challenges:
Challenges of using basalt formations for CO₂ storage include the need for deep drilling and managing high pressures to effectively inject CO₂, ensuring that the injected CO₂ remains trapped and does not migrate through robust monitoring and verification technologies, and addressing the significant costs associated with the infrastructure and technology required for CO₂ injection and monitoring.

In summary, basalt formations offer a promising solution for the long-term storage of CO2 captured through various CCUS technologies. By leveraging the natural reactivity of basalt with CO2, this method provides a stable and permanent means of reducing atmospheric carbon dioxide levels, contributing to global climate change mitigation efforts.