In the quest to combat climate change and reduce greenhouse gas emissions, carbon capture and storage (CCS) has emerged as a promising technology. CCS involves capturing carbon dioxide (CO2) emissions from industrial processes and power plants, followed by transporting and securely storing the captured CO2 deep underground.
This article aims to demystify the concept of carbon capture and storage, explaining how it works and its crucial role in mitigating climate change.
What is Carbon Capture?
Carbon capture refers to the process of capturing CO2 emissions from sources such as power plants, cement factories, and other industrial facilities before they are released into the atmosphere. The captured CO2 is then prepared for transportation and storage. This prevents a significant amount of CO2, a major contributor to global warming, from entering the atmosphere.
Carbon capture and storage (CCS) is a relatively new technology that could greatly reduce carbon emissions and in turn combat global warming.
The technology is designed to capture carbon dioxide (CO2) emissions and store them permanently underground, as a greener alternative to releasing them into the atmosphere.
How Carbon Capture Works:
When fossil fuels are burned they produce carbon dioxide – a greenhouse gas that contributes to global warming.
CCS therefore involves capturing the waste gases right at the source of their creation – such as power plants and industrial facilities that make steel and cement.
Once extracted, the CO2 is transported to a storage site via pipelines, or, often when the storage site is far away, by road vehicles or ships.
The storage site is usually an underground cavern, like a depleted oil or gas reservoir, or a formation of porous rocks that have good gas storage potential, known as a saline aquifer.
The carbon dioxide is then left there permanently, but is monitored to ensure it remains safely contained and is not prone to leakages.
Another slightly different process known as ‘carbon capture, utilisation and storage’ (CCUS) involves reusing the CO2 in industrial processes by converting it into plastics, concrete or biofuel, for example.
What is Carbon Storage?
Carbon storage, often referred to as carbon sequestration, is the process of securely storing the captured CO2 deep underground in geological formations. The aim is to prevent the released CO2 from re-entering the atmosphere, thus reducing its impact on global warming.
How Carbon Storage Works:
- Geological Storage: The most common form of carbon storage involves injecting captured CO2 into deep underground geological formations. These formations include depleted oil and gas reservoirs, deep saline aquifers, and unmineable coal seams. The CO2 is stored in the pores of rocks, often trapped by impermeable layers above.
- Enhanced Oil Recovery (EOR): In some cases, CO2 is injected into oil reservoirs to enhance oil recovery. This technique not only stores CO2 but also increases oil production. However, the primary focus is shifting towards non-EOR storage due to its potential for larger-scale emissions reduction.
Benefits and Challenges:
- Emissions Reduction: CCS has the potential to significantly reduce CO2 emissions from major industrial sources, helping to achieve climate goals.
- Transition Technology: CCS can provide a bridge to a low-carbon future while enabling the continued use of fossil fuels during the transition.
- Cost: Implementing CCS technology can be expensive, from capture and transportation to storage. Government support and policy incentives are often crucial to its viability.
- Monitoring and Leakage: Ensuring that stored CO2 remains secure and does not leak back into the atmosphere requires rigorous monitoring and verification.
Carbon capture and storage is a vital component of the global efforts to mitigate climate change. By capturing and securely storing CO2 emissions from industrial sources, this technology has the potential to play a significant role in reducing greenhouse gas concentrations in the atmosphere.