Carbon capture and storage (CCS) technology aims to permanently keep carbon dioxide out of the atmosphere by collecting carbon from industrial processes or fossil fuel powerplants, then storing it deep underground either in saline formations or depleted oil fields.
CO2 capture usually begins by treating flue gas with an amine solution before compressing and transporting to its storage site.
1. Capture
Carbon capture and storage (CCS) technology enables facilities such as power plants, steel factories, or any industrial complex to capture carbon dioxide before it escapes into the atmosphere and store it underground geological formations for long-term storage.
Most CCS systems rely on organic molecules called amines to separate CO2 from other gases it comes into contact with during industrial processes, then compressing and injecting it deep underground rock formations like depleted oil/natural gas reservoirs or saline aquifers.
Current uses for captured CO2 include enhanced oil recovery (EOR). EOR involves injecting CO2 into existing oil fields to boost production and retrieve additional oil reserves. CO2 may also be used to make chemicals or fuels, though this will require large amounts of energy, making CCS costly.
2. Transport
CO2 captured from power plants and other industrial processes is transported via pipelines, trucks, or ships to an appropriate storage site, usually deep underground geological formation such as saline reservoirs or depleted oil and gas wells.
Carbon capture and storage (CCS) is an indispensable technology that can reduce emissions from fossil fuel-fired power plants, with applications including BECCS (bioenergy with carbon capture and storage) and direct air capture (DAC).
Structured trapping is used to store CO2 underground using injection of CO2 into rock formations where its movement will be stopped by seal rocks and faults; water also serves as a natural barrier to CO2. CCS technology has proven particularly popular for enhanced oil recovery (EOR), with 30 commercial-scale projects operating worldwide and another 153 currently under development.
3. Storage
CO2 captured during capture is transported to geological storage sites where it will be permanently stored underground – this may involve deep rock formations like depleted oil and gas reservoirs, coal beds or saline aquifers.
United States currently boasts 15 carbon capture and storage (CCS) facilities, capable of capturing an estimated annual amount of CO2 emissions equating to less than 0.4% of national total emissions.
Carbon capture and storage (CCUS) technologies are key to realizing long-term energy transitions away from fossil fuels, with leading climate scenarios depending on rapid scale-up to meet emission reduction targets. Many anticipate significant cost reduction in producing zero-carbon electricity using renewables through using this technology. To facilitate its widespread deployment globally, regulatory frameworks that oversee selection, monitoring, verification and long-term stewardship of storage sites worldwide have been established so as to prevent CO2 injected underground from leeching back out into the environment, potentially endangering human or environmental health.
4. Utilization
Carbon capture and utilization (CCUS) projects must utilize their captured CO2, with one common application being enhanced oil recovery (EOR), where CO2 is pumped directly into an existing oil field to increase production. Another possible use involves mixing CO2 with hydrogen to make synthetic fuels that could eventually replace fossil-based liquid fuels in applications such as airplanes or trucks.
In these instances, the resultant synthetic fuel or material also offers environmental benefits. Captured carbon dioxide can also be combined with cement and steel to make concrete with lower carbon intensity for construction materials.
Carbon capture projects are being installed across North America and internationally, including some at power plants using pre-combustion technology. But to meet ambitious greenhouse gas emission reduction goals set by Paris Agreement, CCUS industry must increase growth at an even faster pace and scale up as quickly as possible.