New Sunlight Reactor Produces Fuel 269
eldavojohn writes "A new reactor developed by CalTech shows promise for producing renewable fuel from sunlight. The reactor hinges on a metal oxide named Ceria that has very interesting properties at very high temperatures. It exhales oxygen at very high temperatures and inhales oxygen at very low temperatures. From the article, 'Specifically, the inhaled oxygen is stripped off of carbon dioxide (CO2) and/or water (H2O) gas molecules that are pumped into the reactor, producing carbon monoxide (CO) and/or hydrogen gas (H2). H2 can be used to fuel hydrogen fuel cells; CO, combined with H2, can be used to create synthetic gas, or "syngas," which is the precursor to liquid hydrocarbon fuels. Adding other catalysts to the gas mixture, meanwhile, produces methane. And once the ceria is oxygenated to full capacity, it can be heated back up again, and the cycle can begin anew.' The only other piece of the puzzle is a large sunlight concentrator to raise the temperature to the necessary 3,000 degrees Fahrenheit. The team is working on modifying and refining the reactor to require a lower temperature to achieve the two-step thermochemical cycle. Another issue is the heat loss which the team claims could be reduced to improve efficiency to 15% or higher. Since CO2 is an input, the possibility exists for coal and power plants to collect CO2 emissions to be used in this process which would effectively allow us to "use the carbon twice." Another idea listed is that a "zero CO2 emissions" is developed along these lines: 'H2O and CO2 would be converted to methane, would fuel electricity-producing power plants that generate more CO2 and H2O, to keep the process going.' The team's work was published last month in Science."
Re:CalTech? (Score:5, Informative)
So it was *mostly* CalTech guys, using Swiss equipment for testing and further development.
Re:Simply Amazing ~ Free Energy (Score:4, Informative)
I believe we've been thinking of it for decades ... but, apparently, it's hard to actually do on a large scale and affordably. At least, that's kinda the impression I've gotten over the years.
Re:Simply Amazing ~ Free Energy (Score:2, Informative)
Putting stuff into space resolves the reliability issue, but only multiplies the cost.
Re:Loads of Potential (Score:5, Informative)
And that's what's probably the better long-term goal here: Convert atmospheric CO2 into some gasoline-like fuel, and use that as fuel in more mobile or space-constrained applications, where it generates CO2. You are back to a closed loop again, and humanity can be sustainable on our current resources. (With the external energy input of the Sun.)
Of course, you'd be limited by the amount of energy you can harvest from sunlight, but that's really a problem no matter what you do, in the longer term...
Old News (Score:4, Informative)
This has already been discussed two years ago here http://hardware.slashdot.org/story/08/01/06/1620228/Scientists-Recycle-CO2-with-Sunlight-to-Make-Fuel [slashdot.org].
Re:How expensive is this thing Cerium? (Score:3, Informative)
According to http://www.chemicool.com/elements/cerium.html [chemicool.com]
Cost, pure: $162 per 100g
Cost, bulk: $1.20 per 100g
Source: Cerium is the most abundant of the lanthanides. It is not found free in nature but is found in a number of minerals, mainly allanite, bastnasite and monazite. Commercially, cerium is prepared by electrolysis of the chloride or by reduction of the fused fluoride with calcium.
The increased cost of the pure element Ce comes from refining it via electrolysis from it's naturally occuring state in various rare minerals. The article does not seem to mention the energy costs of refining the Cerium. So, although with this element, no electrolysis is needed to separate C from O2, electolysis is needed to obtain the element itself. Nothing is free (except Linux maybe).
Re:How expensive is this thing Cerium? (Score:5, Informative)
That strange and exotic metal Cerium, is it at least cheaper than gold? How rare is this? Admittedly it sucks to have our oil stuck under their sand, but trading it for our Cerium stuck in their jungle is not a better solution either.
It's strange and exotic, at say, McDonalds or Pick n Save food store. On the other hand, Home Depot probably sells cans of it and its widely industrially available in bulk and used for all kinds of things.
Its extremely cheap compared to gold. Heck its pretty cheap compared to nickel, tin, and only about twice as costly as copper. Its about ten time as expensive as bulk raw aluminum per pound.
Its a relatively common semi-industrial metal used in all manner of catalysts and especially grinding processes. Cerium Oxide grinding paste sells for about $10 per pound. You can pay more retail in small cans if you'd like, or perhaps you could contract down to 50 cents per ounce if you bought a unit-train of railroad cars worth of it.
Ask your local (working, not retail) jeweler, whom probably has some quart cans of different size grits for polishing stuff.
Unlike the polishing / grinding industry, the catalyst industry would probably recycle heavily. So I'm thinking it would remain relatively cheap even if usage increased.
Re:How expensive is this thing Cerium? (Score:5, Informative)
http://en.wikipedia.org/wiki/Cerium [wikipedia.org]
http://www.radiochemistry.org/periodictable/elements/58.html [radiochemistry.org]
India, Brazil, USA, Sweden.
It's the most abundant of rare earth metals, and is low to moderate toxicity.
Re:A more immediate likely problem (Score:3, Informative)
Comparing hydrogen to CFCs is a bit of a stretch. First CFCs were used as a propellant that was INTENDED to be released in the atmosphere.
Second the reaction of hydrogen with ozone results in water - one H2 molecule will affect 2 O3 molecules H2 + O3 = H2O + O2.
The chemistry of CFCs is much more detrmimental, in that each Cl ion will affect thousands of O3 molecules as it converts into ClO which then reacts with another ozone molecule resulting in O2 and Cl. This frees up the Chlorine ion to continue the cycle until it eventually falls out the ozone layer or reacts with some of the other elements to form a more stable molecule.