Vattenfall - Capture of CO2

Capture of CO₂

Capture technologies aim at producing a concentrated stream of CO₂ that can be transported to a suitable storage site.

In fossil fired power plants CO₂ represents only a small portion of the flue gas. Other flue gas constituents include nitrogen, oxygen and water vapour. Depending on the type of fuel and power plant process, the CO₂ content in the flue gas varies between 3 and 15 per cent of total volume of flue gas.

The different methods available for capturing CO₂ aim at producing a concentrated stream of CO₂ that can be readily transported to a suitable storage site for injection underground.

There are three principal ways to capture CO₂ produced in large power plants:

• Oxyfuel combustion, where fuel is combusted in oxygen instead of air
• Postcombustion, where CO₂ is removed from the flue gas
• Precombustion, where carbon is removed from the fuel before combustion