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Oxy-Fuel Combustion Capture
This process involves burning fossil fuels in pure oxygen as opposed to air resulting in a more complete combustion. This results in an exhaust stream which consists of almost pure CO2 (typically 90%) and water vapour, which can be easily separated from the CO2 by condensation.
The main problem with this method is separating oxygen from the air. This is usually completed cryogenically which requires a lot of energy (for a typical 500MW coal-fired power station supplying pure oxygen requires at least 15% of the electricity the plant generates annually). However, a promising new technology called chemical looping combustion is under development. With this technique the oxygen in the air is removed by oxidation of a metallic compound which can be reduced during combustion allowing the oxygen to be released.
Pros
- Potential for 100% CO2 capture.
- Few other harmful emissions due to more complete combustion.
- May be possible to retro-fit the oxy-fuel burners onto modified existing coal power plant
Cons:
- High energy penalty without chemical looping combustion.
- Only at large Development stage in 2007 - first Demonstration plants in planning
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