Carbon Capture and Storage (CCS) technology enables fossil fuel or biomass energy plants to capture CO2, before it escapes into the atmosphere, and store it permanently underground, such as in salt aquifers or depleted oil fields.
However, carbon dioxide can also be utilized for purposes that bring net climate benefits, such as enhanced oil recovery (EOR). There are currently several projects using carbon dioxide in this capacity.
What is CCS?
Carbon Capture and Storage (CCS) technologies have emerged worldwide to reduce CO2 emissions from fossil-fueled power plants and industrial facilities, and inject the captured CO2 deep underground as permanent stores – paving the way towards a low-carbon future energy future. CCS represents one of the most promising technology options to support low carbon energy future.
CCS remains an expensive technology despite decades of research and billions invested globally, including Australia. It raises electricity levels costs 45%-70%. These costs arise due to complex industrial activities involved with capture, transport and storage functions that must operate simultaneously.
CCS projects are either operating or being constructed across the United States, Canada, Norway and Australia, most using CO2 for enhanced oil recovery (EOR), a process which injects CO2 into depleted reservoirs to increase oil production. EOR accounts for roughly seventy five percent of CCS capacity globally today.
Capture
Step one of CCUS involves isolating carbon dioxide from other gases at power plants and industrial facilities. Multiple techniques have been devised for doing this; technology selection depends on which emissions source exists.
Once captured, CO2 is transported via pipeline or ship for storage at its designated facility. At its storage site, it’s typically pumped deep underground geological formations like old oil and gas reservoirs or saline formations for long-term storage.
At present, 15 CCS facilities are operating and 121 are in construction or development – but these represent only a small part of America’s carbon capture capacity. If we hope to slow climate change effectively, many more will need to come online quickly; additionally, investing directly in ways of reducing our carbon footprint such as energy efficiency or switching to renewables is necessary as well.
Transport
CO2 can be removed from the air through various techniques tailored specifically to each emissions source, such as direct air capture (DAC), pre-combustion carbon dioxide capture and utilization, oxy-fuel CCS, or bioenergy with carbon capture and storage (BECCS).
CO2 must then be transported via pipeline or ship to geological storage sites for safe, economical storage. This is one of the more difficult steps as its source and location must be close enough for safe transport of CO2.
CO2 can be stored permanently underground in geological formations like depleted oil and gas fields or coalbeds, or temporarily in shallower formations like depleted oil and gas fields or coalbeds for shorter timeframes. Storage is essential to ensure that CO2 cannot reemit back into the atmosphere and most experts believe CCUS combined with permanent storage is an excellent way to achieve net zero emissions – the latest IPCC report estimates CCUS could even play an essential part of mitigation strategies to limit global warming to 2 or 1.5 degrees Celsius.
Storage
Carbon Capture and Storage (CCS), more commonly referred to as CO2 Capture and Utilization or Carbon Capture Use and Storage, involves the process of capturing emissions from power plants and other energy-intensive industries before they enter the atmosphere and storing the carbon dioxide under ground formations for permanent disposal.
CCUS should only be seen as one part of a holistic strategy to combat climate change and should not be seen as an alternative means of cutting our emissions directly. Instead, its primary function is reducing carbon impacts from high-carbon processes like coal power production as well as steel production, cement manufacturing, oil refining, chemical production and biofuels production.
CCS systems typically involve injecting CO2 into porous rock formations deep underground. They may also be stored on seabed sediments or unmineable coal seams. Wherever its stored, strict monitoring must be implemented to ensure no significant amounts of CO2 leak into shallower formations or escape into the atmosphere, taking into account current scientific knowledge.