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Home | Green Cars News | Technology | Sandia Lab Develops Machine That Turns CO2 Into Fuel

Sandia Lab Develops Machine That Turns CO2 Into Fuel

26 November, 2009 09:55:00

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Researchers at Sandia National Laboratories have built a prototype machine that uses the sun's energy to convert water and CO2 waste from power plants into transportation fuels.

The "Sunshine to Fuel" system could ultimately prove a practical way to recycle CO2 from power and industrial plants into gasoline, diesel, and jet fuel, assuming the process can become at least twice as efficient as natural photosynthesis.

Instead of just pumping CO2 underground for permanent storage, the sun's abundant energy can be used to achieve "reverse combustion" that essentially turns carbon dioxide back into a fuel.

Called the Counter-Rotating-Ring Receiver Reactor Recuperator (CR5), the cylindrical machine consists of two chambers on the sides and 14 rotating rings in the center.

The outer edges of the rings are made of iron oxide. When the scientists heat the inside of one chamber to 1,500C with a solar concentrator, the iron oxide undergoes a thermo-chemical reaction where it gives up oxygen molecules. As the rings rotate (at one revolution per minute), the hot side approaches the opposite chamber and begins to cool down.

When carbon dioxide is pumped into this chamber, the iron oxide retrieves oxygen molecules from the carbon dioxide, transforming it into carbon monoxide. The carbon monoxide could then serve as a building block to create a liquid combustible fuel.

The process is continually repeated, turning an incoming supply of CO2 into an outgoing stream of carbon monoxide.

James Miller, a chemical engineer with Sandia's advanced materials laboratory, says the same process can be used to produce hydrogen, the only difference being that water, instead of carbon dioxide, is pumped into the second chamber. The two separately retrieved gases--hydrogen and carbon monoxide--are then mixed together to make syngas, which can be used to make a "drop-in replacement" for traditional fuels.

Scientists figure it will be 15 to 20 years before the technology is ready for market. In the meantime, the goal is to develop a new generation prototype every three years that shows an increase in solar-to-fuel conversion efficiency and a decrease in cost. Part of that will come from the development of new ceramic composites that release oxygen molecules at lower temperatures, allowing for more of the sun's energy to be converted into hydrogen or carbon monoxide.

Earlier this year, Joule Biotechnologies has also unveiled its Helioculture technology—a process that harnesses sunlight to directly convert carbon dioxide into SolarFuel liquid energy.

[source: Inhabitat]

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