Carbon capture and storage (CCS) refers to the process of collecting climate-warming carbon emissions at their source, transporting them, and injecting them deep underground in geological formations such as coal seams, saline aquifers or depleted oil fields – an essential technology in combatting global warming.
Liquified CO2 can be shipped by ship between a Carbon Capture and Storage site and its geologic storage location.
Capture
Carbon Capture and Storage (CCS) refers to an array of technologies that remove climate-warming carbon dioxide (CO2) emissions before they reach the atmosphere, by collecting CO2 emissions from industrial processes like steel production or power plant operations; transporting them to geological storage sites for permanent underground storage, then injecting them there for permanent underground storage.
Current applications of CCS include enhanced oil recovery, where it is injected into depleted wells to release unreachable oil reserves. This project, among many others demonstrating safe carbon dioxide storage underground formations.
CO2 can then be permanently stored underground rock formations such as depleted oil and gas reservoirs or saline aquifers for long-term climate solutions that limit global warming to 1.5degC or below. All pathways limiting global warming to this threshold require this as part of their solution plan.
Compression
Carbon capture and storage involves extracting CO2 emissions from industrial sources and depositing it underground, in deep geological formations such as depleted oil or natural gas reservoirs, saline aquifers or unmineable coal areas – where it will then either be temporarily used in different applications or permanently sequestered into the earth through injection.
Refurbishments to pulverized coal power plants usually involve retrofitting CCS systems with large compressors to pressurize CO2 gas captured from exhaust into supercritical liquid form for transport and storage, contributing significantly to capital and operating cost penalties associated with CCS.
Development of innovative technologies that reduce the energy requirement of conventional compression systems is of utmost importance. Shock-compression systems that support CO2 liquefaction at an intermediate stage could significantly decrease capital and operational costs, while waste heat from capture processes could further lower energy usage.
Transportation
CO2 gas captured during capture projects is compressed into liquid form for transport either through pipelines or specially equipped ships, and stored at its intended destination. Transport costs tend to decrease with proximity of capture project to storage site.
CO2 can then be safely and securely pumped underground into geological formations like depleted oil and gas reservoirs or saline aquifers where it will remain permanently stored. This has been practiced in the oil industry for enhanced oil recovery for decades now, showing that CO2 can indeed be safely and securely stored underground.
Capturing carbon dioxide could also be used for other purposes, including creating building materials such as concrete and cement or fuels, with some companies and labs already engaged in turning CO2 capture into useful products like plastics, chemicals, graphene fibers or futuristic carbon nanotubes. CCS installations at coal or gas-powered power plants could make these zero emission, while electric vehicles emit significantly fewer greenhouse gases than their traditional gasoline counterparts; but to become truly zero emission vehicles they’ll need their emissions captured and stored too.
Storage
Carbon capture and storage technology is an essential tool for reaching global climate goals, providing both an immediate solution to decarbonize existing power plants as well as an long-term strategy to achieve carbon neutrality via geologic storage.
Capture technology removes CO2 from the flue gas of fossil-fueled power plants and other industrial facilities using fossil fuels. Once extracted, it’s compressed into liquid form before being transported for permanent underground injection. Large-scale commercial projects are underway throughout the US and internationally.
Transport of CO2 typically involves pipeline transport; this safe and proven process boasts over 50 pipelines spanning 5,000 miles in the United States alone. Once at its destination, it is injected into deep geological formations such as depleted oil and gas reservoirs or saline aquifers for injection.
CO2 can then be physically captured in rock by “structural trapping,” where permeable layers above and below a storage site act as seals to seal in carbon dioxide after it has been injected, while fluids present in its matrix keep it there.