Capturing CO2
We use the expression "CO2 capture" because CO2 is removed from the fuels or flue gases, and then stored. Several CO2 capture technologies exist, and additional methods are being developed. All CO2 capture methods require large investments and so far, the technology has only been tested on a small scale.
Three important methods
CO2 can be removed in three fundamentally different ways:
- CO2 is captured after combustion in the power plant (post-combustion)
- CO2 is captured before combustion in the power plant (pre-combustion)
- Natural gas combustion with pure oxygen (oxy-fuel)
Technology development needed
Both pre-combustion and oxy-fuel technologies require that substantial changes are made to the actual gas or coal power plants. Capture methods require energy input, which means that the net power yield decreases when CO2 capture is employed, and more fuel is needed. Fuel consumption per kWh of power generated typically increases by 18-20 %. Norway, the EU and the USA are studying and developing alternative CO2-capture methods, with the aim of developing technologies that are both more effective and less expensive than today's solutions.
Lectures on Carbon Capture and Storage (CO2NET)
Where are the proposed CCS projects? (Scottish Centre for Carbon Storage)