Monday, October 6, 2008

The growth in emission of carbon dioxide

Why is carbon dioxide (CO2) a problem?
Today molecules of carbon dioxide have increased 100 molecules per million to 380 molecules per million since pre-industrial times. The rising of carbon dioxide molecules leads to boosting global temperature, which will result in rising sea levels and other natural disasters. However, it’s hard to decrease the carbon dioxide into the atmosphere. Since most of the energy come from burning fossil fuel, which produce huge quantity of carbon dioxide, so a challenging problem for the engineers is to develop a system to capture and store the carbon dioxide.
How do you capture CO2?
A chemical system is used to capture carbon dioxide. Smokestacks of coal-burning electric power plants could be replaced with absorption towers. One tower would contain chemicals that isolate carbon dioxide from the other gases (nitrogen and water vapor). A second tower would separate the carbon dioxide from the absorbing chemicals.
There are two main ways to alter the combustion process at the outset; one way is burning coal in pure oxygen rather than ordinary air. That would make separating the carbon dioxide from the exhaust much easier.
Another way is to burn coal to produce a synthetic gas, typically containing hydrogen and carbon monoxide. Adding steam to the synthetic gas converts the carbon monoxide into additional hydrogen and carbon dioxide that can be filtered out of the system.
How do you store CO2?
There are two main ways to store the carbon dioxide. The first way is storing the carbon dioxide in depleted oil fields, for example, offers an important economic advantage — the carbon dioxide interacts with the remaining oil to make it easier to remove. And carbon dioxide’s presence reduces the friction impeding the flow of oil through the rock to wells.
Concerns about leaks suggest to some experts that the best strategy might be literally deep-sixing carbon dioxide, by injecting it into sediments beneath the ocean floor. High pressure from above would keep the carbon dioxide in the sediments and out of the ocean itself. It might cost more to implement than other methods, but it would be free from worries about leaks.


National Academy of Engineeing.(n.d.) develop carbon sequestration methods. Retrieved 3th oct,2008 from http://www.engineeringchallenges.org/cms/8996/9077.aspx

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