Carbon capture and storage

From Envirowiki

Carbon capture and storage (CCS) is a method of greatly reducing the emissions of the greenhouse gas carbon dioxide by “capturing” certain pollutants which are emitted from coal power plants and storing them in some manner rather than allowing it to escape into the atmosphere, exacerbating the changes in climate resulting from global warming. A variety of methods for storing the carbon dioxide have been developed, including injecting the gas into underground geological formations, into the ocean, or trapping it within minerals.

As there is a growing concern that the utilization of coal to meet increases in energy consumption in both the United States and China, many see carbon capture and storage as an integral part of the movement to combat global climate change. Since it is unlikely that either country will move away from coal in the coming decades, the particularly strong effects of burning coal will have to be offset or dealt with in some manner or else the fight against global climate change will become that much harder.

[edit] Potential

Carbon capture with monoethanolamine has the potential to reduce CO2 from the life-cycle of by up to 78% from a standard plant^[1].

There are a limited number of potential sequestration sites globally.

[edit] Problems with CCS

CSS is heavily promoted by corporations and governments involved in the coal industry. but there are a number of valid criticisms that are often played down by these same people.

The technology itself may have the side effects of increased human toxicity, ozone layer depletion and fresh water ecotoxicity^[1].

CCS is a fairly unproven technology, having only deployed in one or two test sites. Not all problems have been found, or overcome, and optimistic estimates say that the technology is likely only to become commercially viable in over 10 years, and take until the second part of the century to be widely deployed.

[edit] Storage Problems

CCS storage sites (with the required geology) must be close to power stations, otherwise the cost of piping the gas long distances becomes prohibitively expensive, technically more difficult, and the infrastructure required would require a greater energy input, which, unless it comes from biofuels (which have their own problems) or other renewables, would likely add more CO₂ to the atmosphere.

There are a limited number of geological sites suitable CCS, which means that there is only a limited amount of time that CCS, if it becomes viable, could be used. most proponents assume that CCS could be used with an otherwise business-as-usual approach. this could mean that at the end of it's useful lifecycle, CCS would leave us in the same position we are now (requiring immediate cuts to carbon emissions).

Carbon dioxide is acidic when dissolved in water. Carbon Dioxide has the ability to acidify aquifers, which could be a problem if those aquifers are use for irrigation, drinking, or run into streams and rivers. There are also risks associated with the acid dissolving certain types of rock, if these rocks are used for storing the carbon dioxide.

Carbon Dioxide is also, in large concentrations, a suffocant. it has been known to wipe out large populations when released from volcanic lakes (See the Lake Nyos Disaster, on Wikipedia). This is not as likely with CCS, but lower-volume leakages are definitely possible, or even likely.

[edit] Existing Projects

There are currently three operating carbon sequestration projects, none of which are commercial.

• Australia: The Otway Basin demonstration Project
• Norway: in the north sea
• US: Saskatchewan

[edit] See Also

• Carbon Capture and Storage in Australia

[edit] references

1. ↑ ^{1.0 1.1} Koornneef, Joris; Tim van Keulen, André Faaij, Wim Turkenburg. "Life cycle assessment of a pulverized coal power plant with post-combustion capture, transport and storage of CO2". International Journal of Greenhouse Gas Control In Press, Corrected Proof. DOI:10.1016/j.ijggc.2008.06.008. Retrieved on 2008-08-18.

[edit] External links

• Clean coal on the Rising Tide Newcastle website discusses some more problems with CCS.