Carbon Capture and Storage (CCS) is a technology group designed to trap carbon dioxide (CO2) emissions from industrial sources before they reach the atmosphere. The captured CO2 is then transported and permanently stored deep underground, mitigating its impact on climate change for hard-to-abate sectors.
Carbon Capture and Storage (CCS), sometimes referred to as Carbon Capture and Sequestration, is a crucial technological strategy for climate change mitigation. Its primary purpose is to decarbonize major industrial sectors—such as power generation, cement production, and steel manufacturing—where emissions are often an unavoidable byproduct of the process. By capturing CO2 at the source, CCS technology prevents significant amounts of greenhouse gases from entering the atmosphere, playing a key role in achieving net-zero emission targets.
The CCS process is comprised of three main stages:
- Capture: CO2 is separated from other gases produced at large industrial facilities. There are several methods for this, including post-combustion (capturing CO2 from flue gases after fuel is burned), pre-combustion (processing the fuel before it's burned), and oxy-fuel combustion (burning fuel in nearly pure oxygen to create a more concentrated CO2 stream).
- Transport: Once separated, the captured CO2 is compressed into a liquid-like state. It is then transported via pipelines, ships, or road tankers to a suitable storage site. Pipelines are the most common and cost-effective method for large volumes.
- Storage (Sequestration): The CO2 is injected into deep, underground geological formations for permanent storage, typically at depths of one kilometer or more. These sites, such as depleted oil and gas reservoirs or deep saline aquifers, are selected for their ability to securely contain the CO2, with an impermeable layer of "cap rock" preventing any leakage back to the surface.
Concrete Examples
- Power Generation: The Boundary Dam CCS Facility in Saskatchewan, Canada, was one of the first commercial-scale projects to retrofit a coal-fired power plant with carbon capture technology. It captures CO2 that would otherwise be emitted and uses some of it for enhanced oil recovery before permanently storing the rest.
- Industrial Processing: The Sleipner Project in Norway captures CO2 from a natural gas processing plant in the North Sea. Since 1996, it has successfully injected approximately one million tonnes of CO2 per year into a saline aquifer beneath the seabed, demonstrating the long-term viability of geological storage.
By enabling deep emissions cuts in critical industries, CCS technology is an important complement to policies like carbon pricing. Facilities that invest in CCS can significantly reduce their need to purchase emissions allowances on compliance markets [Learn more about the EU Emissions Trading System (EU ETS)]. For a comprehensive overview of global CCS projects and policies, the International Energy Agency (IEA) provides authoritative reports and data [link to the IEA's CCS page].