Carbon capture and storage (CCS) involves collecting CO2 emissions from power plants or industrial facilities for permanent underground storage or incorporation into products like concrete.
Geological sequestration of CO2 emissions is the preferred means for storing captured carbon. Pennsylvania offers many such sites suitable for this method of storage.
Capture
Carbon capture and storage technologies encompass various methods for capturing CO2 from industrial emissions, transporting it for storage in deep underground reservoirs, and injecting it directly back into them for permanent disposal. They are commonly employed at fossil fuel power plants as well as other facilities with higher concentrations of CO2.
CCS technology requires more complex equipment than that typically employed to capture natural gas and syngas on a large scale, as its processes involve complex capturing and storage processes that vary considerably in performance over conventional plant processes. Furthermore, its performance variation increases significantly due to such complexity of operation.
Numerous projects designed to showcase or test new capture technologies, communicate a corporate decarbonisation strategy or deliver electricity have become commercialized but do not receive incentives to operate at optimal efficiency and maximize climate benefits. Shortfalls in CO2 captured relative to their design capacity can partly be explained by plant operators choosing not to run full CO2 capture when there is lower power demand than expected.
Transport
CCS technologies capture CO2 from waste gases and transport it to sites for permanent storage – typically salt aquifers or depleted oil and gas reservoirs deep underground.
CO2 can be transported by truck and ship, but pipelines offer the most cost-efficient method of moving large volumes of carbon dioxide. They can connect industrial emissions sources like steel mills, cement plants, petrochemical refineries, ammonia production facilities and direct air capture plants with geologic storage or utilization sites for long-term storage or use.
At present, several long-distance CO2 pipelines are operating, including one in Alberta which transports captured CO2 to an enhanced oil recovery (EOR) field. Unfortunately, however, most of these projects are driven by commercial rather than climate incentives, meaning that they do not operate at scale to prevent atmospheric CO2 concentrations reaching dangerously high concentrations – this would only be achieved through policies making these technologies financially sustainable on an industrial scale.
Storage
Carbon dioxide emissions sources are captured and transported underground where they’re permanently stored as part of carbon capture and storage (CCUS) systems that prevent atmospheric concentrations of CO2 from exceeding levels that threaten climate stability, including dangerous warming. According to widespread scientific consensus, large scale implementation of CCUS deployment must take place if this solution is to be effective.
Once pressurised, CO2 is injected into rock formations such as former oil and gas reservoirs, unminable coal seams or saline aquifers. For safety purposes, these injection sites are protected with thick sealing layers beneath the surface that keep out any drinking water or other sensitive resources that might come into contact with it.
At present, 41 commercial CCS facilities are operating globally. While many of these projects were not specifically created with climate goals in mind, their track record demonstrates that CO2 capture and storage can be achieved on a large scale today. These frontrunners help us make progress toward our global climate goals.
Utilization
CO2 captured from fossil fuel power plants’ flue gas is typically separated into its constituent parts (CO2, water and ash) in order to transport or store it. As this is a complex process using relatively new technology, these frontrunner projects may encounter issues at times.
Snohvit project in Norway experienced 28% outages during its inaugural year due to equipment problems (e.g. absorber fouling and solvent “foaming”); these technical issues were mostly resolved with simple practical solutions such as enhanced cleaning practices or additional system redundancy.
Today’s carbon capture and storage projects tend to be constructed for commercial reasons; CO2 captured from oil field operations for EOR purposes or stored deep geological formations can then be sold back for sale on the open market. But for CCS technologies to help meet climate goals set forth in Paris Agreement goals effectively, these projects must also incorporate ways to utilize its by-product CO2, not simply store it away. This requires using its CO2 for more beneficial purposes other than EOR or carbon sink storage.