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High Efficiency Solar Fuel

Posted January 04, 2011 9:00 AM by Sharkles

A new thermochemical reactor has been developed to use sunlight to convert carbon dioxide and water into hydrocarbon-fuel precursors at high efficiency. Researchers are saying that this reactor may be the first step toward producing liquid fuels with solar energy that is more efficient than thought possible with current methods like photocatalysis or microbial fermentation-based hydrocarbon production.

The reactor was designed by Aldo Steinfeld, solar technology specialist for ETH, the Swiss Federal Institute of Technology, Sossina M. Haile from the California Institute of Technology, and coworkers. Concentrated solar energy is used to thermochemically dissociate CO2 and H2O with cerium oxide redox reactions, producing CO and H2 with the 02 as a byproduct. The CO and H2 form syngas, which is processed for menthanol, gasoline, and other liquid fuel production.

Source: Chemical & Engineering News

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#1

Re: High Efficiency Solar Fuel

01/04/2011 4:00 PM

Magnificent ! We are not only still polluting, but extracting the fuels from two compounds that are esential to life, modifying their (as eco-nuts would say) delicate balance.

Sorry I couldn't resist; I actually suspect that the impact of human activities on our environment is not as bad as leaving diseases progress, not to extract and distribute energy, not having invented transportation means, not to chemically improve crops, and a long, long etcetera.

Yahlasit

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Associate

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#2
In reply to #1

Re: High Efficiency Solar Fuel

01/04/2011 11:07 PM

Well if we take co2 from the air them we are cleaning the air and the resulting fuel is like a oil relate fuel. That mean we are doing a circle. But we still need better engines than the ones we have until now.

javier

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#3
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Re: High Efficiency Solar Fuel

01/04/2011 11:47 PM

CO2 is not a pollutant, it is an essential nutrient of plants. No CO2, no photosynthesis. Not that it matters in this case because:

All the thermochemical reactors in the world won't have the slightest impact on atmospheric CO2 levels, as the oceans are an essentially inexhaustible reservoir of CO2

The CO2 used to operate the reactors won't come from the atmosphere - CO2 is a tiny fraction of the air, so the process would be hopelessly inefficient. Best would be to tack these onto breweries or other plants producing lots and lots of concentrated, clean CO2.

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Associate

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#4
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Re: High Efficiency Solar Fuel

01/05/2011 12:44 AM

Long time ago, the plants using photosynthesis trap the CO2 from the atmosphere and wen they die and the animals eating plants die too they left a legacy of mineral carbon and oil underground. They clean the atmosphere of CO2 too. they change the atmosphere from 5% to 20% oxygen and left open the door for more advance oxygen breathing animals. Today using oil we are releasing the CO2 into the atmosphere. It is true that the oceans are an essentially inexhaustible reservoir of CO2 but it is getting to the limit. A way to take the CO2 from the atmosphere, use it like a fuel and put it back to the atmosphere will be the ideal way to get solar energy and use it in engines and stop releasing the CO2 from the mineral oil and carbon

javier

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Guru

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#5

Re: High Efficiency Solar Fuel

01/05/2011 1:42 AM

This is the old separate CO2 to CO using half the bond energy (one O's worth), then burn it back to CO2, (yielding less than say 40% of recombination energy via internal combustion) "smoke and mirrors".

Bottom line: You can't cheat enthalpy.

The most this could achieve is a "storage friendly medium".

And you can bet, if you do the full process sums, it will yield less than an equivalent kWh input to PV hydro re-pumping, returned via electric motors, or resistance heating.

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