About Carbon Capture and Storage
CCS is a low-carbon technology which captures CO2 released from coal and gas for power generation and from other industrial processes and transports it offshore for safe and permanent underground storage. In GB storage of CO2 will only take place offshore.
Currently there are three different capture technologies available to capture CO2:
- Post-combustion capture of CO2 occurs after the burning of fossil fuels. CO2 is separated from flue gas when it is passed through a liquid which causes a chemical reaction. This is also called scrubbing.
- Pre-combustion capture is where CO2 is separated or removed prior to the burning of fossil fuels. The pre-combustion technology converts fossil fuels into a gas made up of CO2 and Hydrogen (H2). These gases are then separated, with H2 used to fuel the power plant.
- Oxyfuel combustion burns fossil fuels with nearly pure oxygen. The flue gas produced only contains CO2 and steam. These are separated by a cooling process with the water condensing leaving a flue gas of almost pure CO2.
CO2 is likely to be transported by pipeline from the capture site to an offshore installation located near a suitable underground reservoir. However, in some cases, tankers may be used to transport CO2 to offshore installations.
The final stage of the CCS process involves injecting CO2 at high pressure from an offshore installation into a deep geological formation such as depleted oil or gas reservoirs, or a saline aquifer. Potential storage sites will be chosen on the basis of their ability to safely contain stored CO2 without leakage.