Self-Sustaining Solar Reactor Creates Clean Hydrogen 406
An anonymous reader writes "A mechanical engineer working out of the University of Delaware has come up with a way to produce hydrogen without any undesirable emissions such as carbon dioxide. The solar reactor is capable of using sunlight to increase the heat inside its cylindrical structure above 3,000 degrees Fahrenheit. Zinc oxide powder is then gravity fed through 15 hoppers into the ceramic interior where it converts to a zinc vapor. At that point the vapor is reacted with water separately, which in turn produces hydrogen. If the prototype gets through 6 weeks of testing at the Swiss Federal Institute of Technology located in Zurich, we could see it scaled up to industrial size, producing emission-free hydrogen."
Darn that dirty hydrogen (Score:5, Insightful)
Re:Darn that dirty hydrogen (Score:5, Insightful)
Finally, a source of clean hydrogen.
That is true, but isn't one of the big problems with Hydrogen storing it [wikipedia.org], not just producing it? I mean, don't get me wrong, it is excellent to see that part of this "we want to use hydrogen" problem solved, but a lot more still needs to be done.
40 rods to the hogshead (Score:1, Insightful)
Am I the only one who gets annoyed when scientific articles use archaic scales like Fahrenheit?
And what about that ZnO? (Score:2, Insightful)
How much energy and other resources will be required to first mine all that zinc and then create the oxide to use in this device? What other costs of the process are being omitted here?
Re:Darn that dirty hydrogen (Score:5, Insightful)
When we (the US) get rid of the penny there will be a HUGE supply of zinc out there.
production does not equal efficient production (Score:5, Insightful)
I'm not an engineer, so get out your salt-lick before reading...but, they've developed a "proof of concept" device. I don't know if it's even appropriate to discuss "practical" uses of this device, yet. It's possibly a very expensive way to produce hydrogen and may not be meant to see much light of day outside academic circles.
One interesting feature of the reactor is that, in theory, the zinc oxide byproduct created during the reaction will be re-usable, making the project self-sustaining.
“This is probably the most complex device built by a graduate student in the history of our department,” added Prasad. “If he is successful, one day, we can imagine a huge array of mirrors out in the desert concentrating sunlight up into a large central tower containing a larger version of Erik’s reactor and making hydrogen on an industrial scale.”
So there's "hope", but is currently experimental:
We [they] will measure the temperature and the production of oxygen inside the reactor in real time, which will tell us how much solar fuel or zinc we are actually producing,” Koepf explained.
All of the above from TFA.
Re:40 rods to the hogshead (Score:4, Insightful)
2. Neither of the links in the submission go to a scientific article. One goes to a press release on the UD website, and the other goes to a blog that summarizes the press release.
3. Complaining about customary units does not make you cool or indicate scientific literacy. However, it does make you sound like pedantic, whiny bitch.
You may now go back to looking at cat pictures and masturbating.
Re:Global Warming! (Score:4, Insightful)
water ( aka dihydrogen monoxide ) is far less of a concern with respect to the greenhouse effect than CO2 is.
Its far better on the environment to emit water vapour instead of CO2.
Re:Darn that dirty hydrogen (Score:5, Insightful)
It operates at ~1700C. You're not going to get sustained temps like that without large mirrors and large reactor vessels. So it's not going to scale down terribly well.
Re:Darn that dirty hydrogen (Score:2, Insightful)
It would make for a wonderful closed circuit...
For a closed circuit wouldn't we also end up with a pile of zinc oxide?
Re:40 rods to the hogshead (Score:5, Insightful)
1) While it's in use by a lot of people, _most_ people don't use it.
2) It's about a scientific article, so we're talking about science. It just makes sense to use celsius or kelvin in a science topic. If we're talking about the distance between planets, we use AU or light years. If we're talking temperature, fahrenheit is not the first choice.
Re:Darn that dirty hydrogen (Score:5, Insightful)
Well, scaled really small, it just works slower to fill your H2 tanks.
Photo-voltaic panels ---> Electricity--> heat small continuous flow reactor chamber (maybe no bigger than your thumb). Maybe the whole package sits beside your house in a package the size of an air conditioning compressor, while the panels are on the roof. We got a boat load of roofs in this country.
Re:Byproduct of hydrogen combustion (Score:2, Insightful)
The warmer the atmosphere, the longer water vapor will remain gaseous and the higher the saturation point. We're told the atmosphere is already warming and will continue to do so. It seems rather risky to bellow the most dangerous greenhouse gas of all directly into the air in quantities this planet has never seen before.
Re:Byproduct of hydrogen combustion (Score:2, Insightful)
You're ignoring the effects of atmospheric heating on that cycle. Thanks for the ad hominem as a bonus.
Self-sustainable... pfft. (Score:5, Insightful)
It's not self-sustainable. It's sustained by the sun.
Re:so... (Score:2, Insightful)
Because Pushing-Robot apparently can't read, I've gone and done some investigation myself. From what I've been reading, it seems the most common method is by burning zinc ores or through carbothermal reduction to produce zinc vapor which then is mixed with oxygen to produce a zinc oxide runoff. These generally both produce large carbon output.
Using the device itself to burn zinc ore (in order to produce zinc vapor and additional fuel) will still produce carbon dioxide as a by-product. You need purified zinc to avoid this, and there are no clean purification methods.
The wet chemical process still results in zinc carbonate which needs to be heated to be refined to zinc oxide, releasing the carbon.
Laboratory production by electrolyzing a solution of sodium bicarbonate with a zinc anode produces useful zinc hydroxide and hydrogen gas. However carbon and sodium are released as waste.
Is there a way this can actually be produced without releasing carbon, or is this reactor just shifting the problem elsewhere like so many "green" solutions?
Re:Darn that dirty hydrogen (Score:0, Insightful)
Um, you're dumb, and I'm being charitable.
Re:Darn that dirty hydrogen (Score:0, Insightful)
This is capitalism, remember? The slaves must be kept working by the constant inflation of the currency. How dare you use logic against our exponential imperialism!
Re:Byproduct of hydrogen combustion (Score:4, Insightful)
Re:Byproduct of hydrogen combustion (Score:5, Insightful)
I know that you're being deliberately obtuse, but for the benefit of any people who may not see through your little charade, I'll point out the key difference between water vapor and the CO2 this technology would be replacing: The half life of CO2 in the atmosphere is nearly a century. The half life of water vapor is a couple of days.
Re:Byproduct of hydrogen combustion (Score:5, Insightful)
Re:Darn that dirty hydrogen (Score:4, Insightful)
Maybe to not have to deal with not being able to produce power at night? Yes, the fuel can only be generated during daylight hours, but the fuel can be consumed at any time.
Re:so... (Score:4, Insightful)
Unless you are being unnecessarily pedantic, the ZnO should be considered as a one-off, sunk cost and therefore this does indeed represent "carbon-free energy":
Zinc-Zinc Oxide Cycle [wikipedia.org]
The reaction regenerates the ZnO at the end of the cycle (reminiscent of a catalyst); therefore, the net reaction is H2O -> H2 + 1/2 O2. So, while the reactor requires some quantity of ZnO to bootstrap itself, very little (or no) additional ZnO should be required to keep it operating. If this particular prototype reactor doesn't fully regenerate & reuse the ZnO, then that is a limitation of the particular implementation and not a limitation of the thermochemical cycle itself.
However, if you were intending to be pedantic in the sense that almost *nothing* can be built without generating some sort of carbon dioxide emission (eg. if you consider wind energy to be "non carbon-free energy" because CO2 is produced during the manufacture of wind turbines), then please accept my opprobrium for your pedantry.
Re:Darn that dirty hydrogen (Score:5, Insightful)
You are talking "energy density" as density relates to weight. Unless you're talking spacecraft, energy density related to volume is usually a lot more important. Look at your car's design. When the engineers designed your car, were they more worried about the WEIGHT of the gas in the tank, or the VOLUME of the gas tank? If the weight of the gas went up 50%, probably not all that big of a deal, make stronger tank straps and maybe reinforce the tank a little. But imagine the tank SIZE going up 50%. OK now we're seriously eating into your trunk space. Or look at that in reverse, if the manufacturer wants to double battery life in your MP3 player, he can make it twice as heavy or twice as BIG, which do you think he will want to do, which product will people buy, the heavier one or the big brick? Here down on earth, size matters. Weight is more important if you're going to orbit it.