Carbon Capture and Storage (CCS) is an energy technology designed to reduce CO2 emissions from power plants as well as industrial processes like cement production or steel production, offering long-term solutions against climate change.
Carbon dioxide that has been captured is stored permanently within deep geological formations, such as depleted oil and gas reservoirs or saline aquifers.
What is CCS?
Carbon Capture and Storage (CCS) is an approach to climate change mitigation that involves collecting carbon emissions at power plants or factories before they escape into the atmosphere. Once captured, the captured CO2 can either be transported and permanently stored underground or used for other purposes.
Multiple large-scale projects have demonstrated the viability of CCS technologies. Most were driven by commercial incentives – for instance increasing oil production – rather than climate considerations, and have provided invaluable operational experience and technical learning, while helping refine and advance CCS technologies.
However, some community-based organizations and environmental activists are critical of CCS. They claim it perpetuates fossil fuel production while risking further health, social, and environmental ramifications for communities already affected by fossil-fueled industrial development. Furthermore, they argue that CCS should only be seen as a temporary measure; we need to seek alternative forms of clean energy solutions in order to achieve our climate goals.
Capturing CO2
Carbon Capture and Storage (CCUS) technologies capture CO2 released from power plants and other industrial facilities and then either permanently store it underground or put to productive use in buildings, fuels or enhanced oil recovery. Leading energy experts believe CCUS should be implemented widely so we can meet global climate targets.
Once separated, CO2 gas is compressed to form liquid form before being transported to a storage site by pipeline, train, ship or road tanker. Once at its destination site, it’s injected deep into geological formations like depleted oil and gas reservoirs or saline aquifers where its presence forms an impermeable seal, preventing further migration laterally or vertically.
Companies and laboratories alike are exploring the use of CO2 to produce useful products like plastics, building materials like concrete, and even fuels; however, commercial viability often precludes its commercial viability without significant government subsidies or performance-based tax credits.
Transporting CO2
Captured CO2 is compressed into liquid form and transported via pipeline or tanker truck to underground storage sites for long-term storage, although ships and rail tankers can also be used. As carbon dioxide is nonflammable it can be safely transported like other oils and gases.
At its storage site, CO2 is injected deep underground into geological formations such as depleted oil and gas reservoirs or unmineable coal seams. This technique has long been employed in enhanced oil recovery to increase oil extraction from wells.
CCUS also encompasses technologies known as utilization or sequestration that put captured CO2 to use, such as producing algae biofuels or building materials or returning it back into the earth for long-term storage. Unfortunately, however, this form of CCUS rarely leads to significant emissions reduction or climate benefits when indirect and other impacts are considered.
Storage
Carbon capture and storage (CCS) is an essential tool in the arsenal of approaches used to mitigate greenhouse gas emissions. CCS works by isolating CO2 from other gases at large industrial processes like coal and natural-gas-fired power plants, steel mills, cement plants and refineries, then transporting and storing it deep underground geological formations.
Geological storage locations can include saline formations (porous rocks filled with salty water), depleted oil and natural gas reservoirs, unmineable coal areas and basalt formations. Each storage site must be carefully chosen and regulated to ensure their safety.
At present, CCS projects that have been constructed worldwide – mostly coal-fired power plants – have proven costly failures. Of those completed so far, most have exceeded budget and schedule commitments while failing to deliver as promised the amount of CO2. Therefore, climate-oriented CCS projects should focus on renewables backed by storage; it offers faster, safer and more cost-effective emissions reduction solutions.