Carbon Capture and Storage: a brief intro.

Source: awards.earthjournalism.org

From the International Energy Agency (IEA) to the Intergovernmental Panel on Climate Change (IPCC) have recognized  Carbon Capture and Storage/Sequestration (CCS) as a feasible technology to reduce CO2 emission from coal or gas fired power planets.  The idea is straightforward, first, CO2 emission can be captured at a specific installation and pressurized to liquid, then liquified CO2 can be transported to a storage site, such as exploited oil field, saline formation or below the seabed.  Moreover, future monitoring plans will be needed to prevent and remediate deficient storage.

source: IPCC, 2005

In principle, there are three methods of carbon capture[1, 2],

1. Postcombustion, in other words, the CO2 is removed after combustion of the fossil fuel.  This technology uses chemical solvents to separate CO2 and is currently applied  to power plants as well as other industrial applications.
2. Precombustion, i.e., the fossil fuel is partially oxidized, and H2 and carbon are separated before combustion taking place. 
3. Oxyfuel combustion, coal or gas are burned in oxygen instead of air to yield CO2 and water.

Likely, there are two main storage options are being considered, geological storage and mineral storage. The former method involves directly inject CO2 into underground geological formations, for example, oil fields, gas fields and saline formations etc.. In the latter one, the CO2 is reacted with metal oxides, which in turn produces stable carbonates. However, according to IPCC, a power plant equipped with CCS using mineral storage will need 60-180% more energy than one without CCS.

So far so good? One may start to worry about the safety issues accompanying this so-called mitigation technology. Moreover, the concern can be put in this way, does it sound more like an excuse of keeping on the track of using fossil fuels? Or does it can help to achieve Kyoto protocol targets without sacrificing a 'civilized' living standard? We may need more research and scientific evidence to make a plausible conclusion.  I'll address more about these considerations of applying CCS in the present and future commercial scale power stations in my following blogs.

References:
1.Wikipedia: CCS
2. R.Stuart Haszeldine, Carbon Capture and Storage: how green can black be, science, 2009.