par Turanil » 28 mars 2009, 09:42
Bon, je ne viens plus que rarement sur Oleocène, donc ceci a peut-être déjà été mentionné auparavant... Sinon, c'est en anglais, je n'en ferai qu'un traduction très succincte.
Dans
l'article suivant, un système à base de nanotubes de carbone exposé au soleil permet de produire du gaz méthane directement à partir du CO2 contenu dans l'air.
Nanotube Tech Transforms CO2 Into Fuel
Eric Bland, Discovery News
March 23, 2009 -- Powered by sunlight, titanium oxide nanotubes can turn carbon dioxide into methane, which can be harnessed as an energy source, say scientists at Pennsylvania State University.
The nanotubes could dramatically reduce CO2 emissions into the atmosphere and reduce our need for fossil fuels.
"Right now there is lots of talk about burying carbon dioxide, which is ridiculous," said Craig Grimes of Penn State, who, along with Oomman Varghese, Maggie Paulose and Thomas LaTempa, co-authored a paper on the nanotubes in the journal Nano Letters. "Instead we can collect the waste out of the smoke stack, put it though a converter, and presto, use sunlight to change [CO2] back into fuel."
The nanotubes are arranged vertically, almost like empty honeycomb. Over the top of the nanotubes sits a thin, reddish-brown layer of copper oxide. Both the copper and titanium oxide act as catalysts, speeding up reactions that take place naturally.
When sunlight hits the copper oxide, carbon dioxide is converted into carbon monoxide. When sunlight hits the titanium oxide, water molecules split apart. The hydrogen freed from the water and the carbon freed from CO2 then recombine to create burnable methane, and the spare oxygen atoms pair up to create breathable oxygen.
The scientists have created thin membranes that cover either 3.8 or 15.5 square inches. So far, those membranes have produced an estimated 66 gallons of methane, said Grimes.
Adding more light and CO2 creates more methane. Grimes estimates that focusing the light collected from 1,100 square feet onto one of the membranes would generate more than 132 gallons of methane on a sunny day.
This is solar power by another name, say Grimes and other scientists. Instead of storing electrons in batteries, Grimes' idea would store energy chemically.
That chemical energy could be used for many things. Methane stored in cylinders could be sold to consumers, much like propane is stored, sold, and used in outdoor grills or for gas stoves. Coal-burning power plants could use the methane to heat water and generate more electricity.
One big advantage of methane over other hydrocarbons like hydrogen gas is that an infrastructure already exists for methane, said Kyoung-Shin Choi, a chemistry professor at Purdue University who was not involved in the research.
"If you want to use hydrogen as a energy source in the future, you have to convert all the existing infrastructure," said Choi. "But we've been using methane for years, and can utilize all the infrastructure we already have."
"It's a clean and sustainable cycle as long as you have sun and water," said Choi.
Whether the process is competitive commercially is still to be determined, said Grimes.
"Do we take that CO2 and bury it, or do we use sunlight to turn it back into fuel?" said Grimes. "Today it's an even draw."
Bon, je ne viens plus que rarement sur Oleocène, donc ceci a peut-être déjà été mentionné auparavant... Sinon, c'est en anglais, je n'en ferai qu'un traduction très succincte.
Dans [url=http://dsc.discovery.com/news/2009/03/23/carbon-dioxide-fuel.html]l'article suivant[/url], un système à base de nanotubes de carbone exposé au soleil permet de produire du gaz méthane directement à partir du CO2 contenu dans l'air.
[quote][b]Nanotube Tech Transforms CO2 Into Fuel[/b]
Eric Bland, Discovery News
March 23, 2009 -- Powered by sunlight, titanium oxide nanotubes can turn carbon dioxide into methane, which can be harnessed as an energy source, say scientists at Pennsylvania State University.
The nanotubes could dramatically reduce CO2 emissions into the atmosphere and reduce our need for fossil fuels.
"Right now there is lots of talk about burying carbon dioxide, which is ridiculous," said Craig Grimes of Penn State, who, along with Oomman Varghese, Maggie Paulose and Thomas LaTempa, co-authored a paper on the nanotubes in the journal Nano Letters. "Instead we can collect the waste out of the smoke stack, put it though a converter, and presto, use sunlight to change [CO2] back into fuel."
The nanotubes are arranged vertically, almost like empty honeycomb. Over the top of the nanotubes sits a thin, reddish-brown layer of copper oxide. Both the copper and titanium oxide act as catalysts, speeding up reactions that take place naturally.
When sunlight hits the copper oxide, carbon dioxide is converted into carbon monoxide. When sunlight hits the titanium oxide, water molecules split apart. The hydrogen freed from the water and the carbon freed from CO2 then recombine to create burnable methane, and the spare oxygen atoms pair up to create breathable oxygen.
The scientists have created thin membranes that cover either 3.8 or 15.5 square inches. So far, those membranes have produced an estimated 66 gallons of methane, said Grimes.
Adding more light and CO2 creates more methane. Grimes estimates that focusing the light collected from 1,100 square feet onto one of the membranes would generate more than 132 gallons of methane on a sunny day.
This is solar power by another name, say Grimes and other scientists. Instead of storing electrons in batteries, Grimes' idea would store energy chemically.
That chemical energy could be used for many things. Methane stored in cylinders could be sold to consumers, much like propane is stored, sold, and used in outdoor grills or for gas stoves. Coal-burning power plants could use the methane to heat water and generate more electricity.
One big advantage of methane over other hydrocarbons like hydrogen gas is that an infrastructure already exists for methane, said Kyoung-Shin Choi, a chemistry professor at Purdue University who was not involved in the research.
"If you want to use hydrogen as a energy source in the future, you have to convert all the existing infrastructure," said Choi. "But we've been using methane for years, and can utilize all the infrastructure we already have."
"It's a clean and sustainable cycle as long as you have sun and water," said Choi.
Whether the process is competitive commercially is still to be determined, said Grimes.
"Do we take that CO2 and bury it, or do we use sunlight to turn it back into fuel?" said Grimes. "Today it's an even draw."[/quote]