Carbon is cycled from gas (C02) to solid (plant tissue) and and back (through fire, digestion, fermentation, etc.) again and again.
Some of that carbon is trapped over long periods in the form of "fossil fuels."
The earth has, in a sense, grown accustom to having a huge chunk of the available carbon stored away in coal and oil, so the recent (last century or so) release of large quantities of this carbon is a problem. This is why fuels made of plants (ethanol, diesel) are of interest. But those fuels require two steps: The carbon is captured by plants, then the plant matter is converted to something that can be burned in machines.
Why not cut out the middle-man, and replace the plant with a machine that may make the process more efficient?
Researchers at Sandia National Laboratories in New Mexico have found a way of using sunlight to recycle carbon dioxide and produce fuels like methanol or gasoline.The Sunlight to Petrol, or S2P, project essentially reverses the combustion process, recovering the building blocks of hydrocarbons. They can then be used to synthesize liquid fuels like methanol or gasoline. Researchers said the technology already works ...
The idea of recycling carbon dioxide is not new, but has generally been considered too difficult and expensive to be worth the effort. But with oil prices exceeding $100 per barrel and concerns about global warming mounting, researchers are increasingly motivated to investigate carbon recycling. Los Alamos Renewable Energy, for example, has developed a method of using CO2 to generate electricity and fuel.
S2P uses a solar reactor called the Counter-Rotating Ring Receiver Reactor Recuperator, or CR5, to divide carbon dioxide into carbon monoxide and oxygen....
The prototype ...[uses] 14 cobalt ferrite rings, each about one foot in diameter and turning at one revolution per minute. An 88-square meter solar furnace will blast sunlight into the unit, heating the rings to about 2,600 degrees Fahrenheit. At that temperature, cobalt ferrite releases oxygen. When the rings cool to about 2,000 degrees, they're exposed to CO2.
The cooling cobalt ferrite rings convert CO2 to carbon monoxide, which can then be used to make hydrocarbons for the production of methanol or gasoline. The cobalt ferrite rings can simply be reheated. If the cobalt ferrite rings are exposed to water vapor instead of CO2, they yank the oxygen off the water molecules, resulting in free hydrogen, another useful fuel.
Environment
Technology
