Carbon capture and storage
From Envirowiki
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.
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[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.
[edit] Leakage
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 is possible.
Geologist and petroleum consultant Wal Muir has said that CCS can leak at 1% per year[2]. Assuming a constant leakage rate, about 18% of the stored carbon would leak over the 40 year lifetime of a coal plant, and over the following 50 years, 50% of the would have escaped, and 75% after another 70 years (160 years total) - see working.
[edit] Ethical problems
There is and ethical question of who is liable for leaks in the future. Since CCS must work practically indefinitely to be effective, future leaks could be catastrophic, especially if the society has been relying on it as a safe storage mechanism and has a safe-climate policy with no safety margin. If such leaks occur 20 years after the CCS plant closes, who would be liable? Quite possibly, the company running the plant would be insolvent, and the scientists, engineers and board members of the company at the time of the development application would likely be dead (considering ~70 years would have passed).
In australia, Christine Milne says that the government is planning to take over liability for leaks after the project runs it's course. Costs from such liability would inevitably fall on the tax-paying public in the end[3].
[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
[edit] references
- ↑ 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.
- ↑ Gurney, Kathryn (2008-09-30). "Fast-Track Clean Coal or Face Rival Fuel Threat", The Australian. Retrieved on 2008-09-30.
- ↑ "The public liable for future carbon leaks: Greens". Simon Lauder (Director). The World Today. Retrieved on 2008-10-01.
[edit] External links
- Clean coal on the Rising Tide Newcastle website discusses some more problems with CCS.
