Carbon Capture and Storage (CCS) technology provides one means for power plants to reduce emissions by collecting CO2 produced during power production, transporting it for permanent storage in geological formations and then permanently disposing of it in geologic formations.
CO2 is stored underground in either saltwater reservoirs or depleted oil fields, following stringent regulations to ensure its safety and security.
The Basics
Carbon Capture and Storage technologies could play a critical role in combatting climate change by collecting climate-warming emissions from power plants and other industrial sources before they enter the atmosphere, before transporting and safely storing it underground in geological formations.
Capturing takes place at emission sources such as power stations and industrial facilities using various processes. Once captured, purification and compression processes may take place to prepare it for transport through pipelines to its final destination – typically a saline or used oil reservoir site for long-term storage.
CCS can also be combined with carbon capture and utilization (or CCUS) so that captured CO2 can be put to good use, for instance in building materials, fertilizer production or chemical production aimed at creating synthetic fuels to replace fossil fuels. This would lower costs significantly while simultaneously transitioning CCUS from being an expensive waste disposal business model to one with self-financing recycling revenue streams – ultimately speeding up the scale up of CCS technologies.
Capture
Carbon capture and storage technology is an invaluable way of mitigating harmful emissions from power plants and industrial processes, while simultaneously helping reach low carbon future goals by decreasing fossil fuel combustion requirements.
This technology works by extracting CO2 from flue gas generated at power plants or other industrial sources like steel, cement and hydrogen production facilities and transporting and storing it deep underground in geological formations.
For CO2 capture from flue gas, an absorber chemically separates it from other gases before compressing into dense liquid-like form for transportation via pipeline to its storage site, where it’s then injected into porous rock formations such as saline aquifers or depleted oil and natural gas reservoirs at depths greater than 0.62 miles (1km). Examples of CCS projects are as follows:
Transport
Once carbon has been captured, it must be transported and stored appropriately – an essential step for CCS as this prevents harmful emissions from returning into the atmosphere and nullifying all its work.
Transport of CO2 involves compressing it to form a dense liquid form before transporting through pipelines to its storage or utilization site. CO2 may also be transported via truck or rail.
Retrofitting existing coal and some bioenergy plants to capture CO2, or conducting direct air capture, will likely be determined by available injection capacity. REGEN models these applications as needing an intricate network of pipelines with feeder and trunk lines for this application.
Construction and operation costs associated with transport infrastructure vary based on region and project scale, from capital costs associated with installing pipelines and compression facilities, as well as ongoing operational costs associated with transportation and injection operations.
Storage
Carbon can be stored underground in geological formations for thousands or millions of years, as part of its natural cycle, with plants storing atmospheric CO2 in woody tissues and grasslands.
Other CCS technologies use carbon capture and storage (CCS) processes to convert CO2 to non-volatile forms such as solid minerals. These substances may then be injected into porous rock formations to physically trap it or combined with rocks to form stable minerals that will remain stable over time. Some of this technology is being tested at commercial scale in the United States through DOE Carbon Storage Program.
Carbon can also be stored in decommissioned oil and gas reservoirs or geological formations like saline aquifers and basalt formations. Each site will undergo rigorous exploration and risk evaluation prior to being considered for CO2 storage; once chosen, its management will ensure both short-term protection of its carbon storage unit, as well as long-term preservation.