New carbon sieve
Filtering Carbon Dioxide may become a real answer for Climate Change.
Researchers have developed porous materials that can soak up 80 times their volume of carbon dioxide. This means the greenhouse gas could be cheaply scrubbed from power-plant smokestacks.
After the carbon dioxide has been absorbed by the new materials, it could be released through pressure changes, compressed, and, finally, pumped underground for long-term storage.
Such carbon dioxide capture and storage could be essential to reducing greenhouse-gas emissions. Countries such as the United States that depend heavily on coal for electricity will see most benefit. The first stage, capturing the carbon, is particularly important, since it can account for 75 percent of the total costs, according to the Department of Energy.
new materials
Developments described in Science were created by researchers at UCLA led by Omar Yaghi, a chemist known for producing materials with intricate microscopic structures. They absorb large amounts of carbon dioxide but do not absorb other gases.
Techniques already exist for capturing carbon dioxide from smokestacks, but they use large amounts of energy - 15 to 20 percent of the total electricity output of a power plant, according to one estimate, Yaghi says. Those materials, called amines, only release the carbon dioxide they’ve absorbed if heated. This means that capturing CO2 could add 90 % to the cost of producing electricity from coal, says Thomas Feeley, a project manager at the National Energy Technology Laboratory.
molecular sponge
The most porous of the new materials that Yaghi reports in Science contain nearly 2,000 square meters of surface area packed into one gram of material. He has demonstrated three new materials are highly selective in capturing carbon dioxide.
While the exact mechanisms are not fully understood, Yaghi thinks that the slightly negative charge of organic molecules in his material attracts carbon dioxide molecules, which have a slightly positive charge. As a result, carbon dioxide is held in place, while other gases move through the material. This method of trapping carbon dioxide is better than some other methods because it doesn’t take much energy to release the gas. [more]
A nice hope, but the whole answer?
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