Carbon capture and sequestration (CCS) involves capturing carbon dioxide (CO2) emissions from large sources, such as power plants or industrial facilities, and storing them in a way that prevents them from entering the atmosphere.
There are several ways to capture CO2 emissions, including:
- Pre-combustion capture: This involves separating CO2 from the fuel before it is burned, using processes such as gasification or chemical looping.
- Post-combustion capture: This involves separating CO2 from the exhaust gas after it has been burned, using processes such as chemical absorption or adsorption.
- Oxyfuel combustion: This involves burning the fuel with pure oxygen, rather than air, which produces a stream of CO2 that is relatively easy to capture.
Once the CO2 has been captured, it must be transported and stored in a way that prevents it from entering the atmosphere. There are several options for storage, including:
- Geologic storage: This involves injecting the CO2 into underground rock formations, such as depleted oil and gas reservoirs, where it can be securely stored for thousands of years.
- Ocean storage: This involves injecting the CO2 into the deep ocean, where it can dissolve in the water and be stored for long periods of time.
- Terrestrial storage: This involves storing the CO2 in soil or vegetation, where it can be used to promote plant growth or be stored in soil organic matter.
Overall, CCS can be an effective way to reduce CO2 emissions from large sources, but it is a complex and expensive process that requires careful planning and monitoring to ensure that the CO2 is securely stored and does not escape into the atmosphere.