Slashdot Mirror
Self-Sustaining Solar Reactor Creates Clean Hydrogen
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."
Finally, a source of clean hydrogen.
Gently reply
Great, just one more think to go wrong when pimply faced teenagers wish to live in a world without zinc.
Could it effectively be mass produced so that it could become a household item, every house having it's own hydrogen generator and turbine which can contribute to the grid? I've always thought that decentralising power production would make it greener, if only because there's less loss to long distance transmission. Either way, I'm holding thumbs for the six week trial.
zinc oxide just materializes out of thin air?
Am I the only one who gets annoyed when scientific articles use archaic scales like Fahrenheit?
It says they will use simulated sunlight matching 10,000 suns. So where would they get that strong of sunlight if this actually proves to work? Will it work with 1/10,000 of that (i.e. our sun in the backyard)?
But it's pointless to speculate about its utility without knowing how much hydrogen a given unit can produce, how much that unit costs, and how much maintenance it will need.
And the four giant robot arms the operator wears don't fill me with confidence.
How can I believe you when you tell me what I don't want to hear?
But if you burn hydrogen, it creates dihydrogen monoxide, a known greenhouse gas!
This is terrible!
How do you produce the zinc oxide powder? How do you produce the cylindrical structure? Not trolling, genuinly asking. If someone with more metallurgical knowledge than me tells me zinc oxide is common and easy to mine, I'll believe it. But it's a question we must ask.
If this were true, you could ignite the hydrogen and produce fresh water and power.
I can't find out what the reaction products are from this device. So water and ZnO goes in. What happens to the oxygen that was tied up with the hydrogen in the water?
Sorry, but gray text on gray background is making my eyes bleed.
Is it any easier to transport hydrogen from where the sun shines to where it's needed as fuel as compared to electricity? It seems that the energy needed for compression and leakage from storage tanks, fittings, and transmission lines would result in significant energy losses. Plus a 200 mile hydrogen pipeline from the sunny desert to a populated area seems prohibitively more expensive than a power line.
Is this hydrogen plant really any better than just creating electricity? Granted, electricity can be hard to store in large quantities, but storing hydrogen is not cheap or easy.
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?
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.
PS: I don't reply to ACs.
...Zinc prices skyrocket as the entire world's supply of Zinc is ground into fine powder.
The article states:
"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."
However, perhaps this is the obvious to ask, but is this project more or less efficient than some of the next-generation solar technologies? Can you give this technology an 'efficiency' value?
We here at the Clean Alternative Fuels Committee see this as just too dangerous to allow and plead to the US Government to outlaw this potentially dangerous technology. We simply can not trust the public with the ability to produce Hydrogen which could lead to the creation of Mini-H bombs. We propose the advancement of existing Hybrid technology as the clean energy alternative for a successful future and is wholeheartedly endorsed by our Charter Members: Chevron, Exxon-Mobile and Shell.
There are already solar towers using massive arrays of mirrors all aimed at the same point. This could presumably use something similar.
finally. the price at my hydrogen pump is way too high!
What is the chemical result when hydrogen is burned? Water vapor.
What is the atmospheric component that is the predominant contributor to the greenhouse effect? Water vapor.
So lemme get this straight: all these disciples of the so-called hydrogen economy want us to burn hydrogen in energy-equivalent amounts as the fossil fuels we use now, thus putting more of the worst greenhouse gas of all directly into the atmosphere? Sure, some of it will change phase and precipitate back into oceans and lakes and rivers, but about the percentage that doesn't?
I have tried searching Web of Knowledge and Academic Search Premier (EBSCO), and I can't find any articles written by Koepf relating to hydrogen, solar, or zinc. I can also find no papers from the advisers dealing with this subject matter. It is entirely possible that they just haven't published anything on this yet, but that seems very sketchy to get press for something that has not yet been published... Hard to say. Anyone else have any luck with finding articles?
Also, zinc oxide is produced as a by product, so what we're seeing is something like...
Zn+H2O -> ZnO + H2
The real question is how to regenerate pure zinc from its oxide. If this technology can go somewhere, producing zinc from ZnO shouldn't require any external energy input (or minimal, if any). It is also entirely possible to just ignore reforming zinc oxide back into zinc, and they probably will at first. I just don't think splitting an oxide salt will be so easy only using high temperatures. Electrochemistry may help, but again, if the net energy gain of this whole process is too low, then it's unlikely to be picked up. Still pretty cool stuff though.
Fist bump, clean hydrogen from a sustainable, renewable, source. Except for the consumption of zinc oxide catalyst... Maybe not self sustaining after all?
it can be stored in vast quantities in the form of formic acid and then released and restored in a continual cycle. there is obviously efficiency losses but apparently its very practical as it allow storage of large amount of hydrogen at a very high density in a room temperature atmospheric pressure liquid,
that is basically as safe as vinegar.
I was thinking this clean hydrogen would be perfect in so many parts of the world where their is plenty of sunlight but the land is otherwise of low value.
ps: its the nail polish like odor that gets released when ants die, and more specifically when they get crushed. its probably something they are sensitive to, so hopefully our green cars in the future dont get covered with ants in because of the pheromone.
doesn't sound terribly down-scalable to me
In the process described, they use sunlight to raise the temperature inside the container to 3,000 degrees Fahrenheit. Then they add zinc, generate zinc oxide, and use that to make hydrogen. With temperatures that high, why not just generate steam and power a turbine to produce electricity?
If the zinc actually adds to the efficiency of the processes (maybe it takes less energy to mine zinc than it will produce in the reaction), why not just use a normal reactor type to heat up the container instead of sunlight? If not, why not make electricity out of the sunlight heated water?
What about heat?
When energy reactors get small and efficient enough that every American home and African village can have one, we are going to have a big problem with heat pollution.
Or, so an argument could be made.
It's not self-sustainable. It's sustained by the sun.
It is no longer uncommon to be uncommon.
I hate university magazine technology boast articles...
"'People have been trying for years to generate hydrogen renewably from sunlight,...'"
How does this technology compare to solar panel --> electricity --> electrolysis --> hydrogen?
(Or even replacing solar panel with solar concentrator + turbine)
Electrolysis technology isn't exactly new, and so I find this hard to get excited about without some measure of its efficiency.
It would be much better to do the following:
Solar Energy + CO2 + 2 H2O => CH4 + 2 O2
We have lots of infrastructure for moving and storing methane already!!!
http://www.science20.com/news_releases/photocatalysis_using_solar_power_make_methane_carbon_dioxide
http://www.scoop.co.nz/stories/SC0410/S00063.htm
Is there anything that ZnO can't do?
http://www.youtube.com/watch?v=lLp4DZmPqYE
Remember "News for Nerds, Stuff that Matters"? Help make it a reality again! http://soylentnews.org
I find it very unusual that the college's article did not mention anything about the traditional engineering measurements on such systems.
It is always energy in versus energy out and the % efficiency and then the energy cost of recycling the zinc.
This leads me to be very speculative.
...from a regular solar generator being used to electrolyze water?
I'd imagine they would have similar efficiencies.
That system, too, would be self sustaining.
Besides, rather than burning the produced hydrogen for power, wouldn't it be better to use the solar power directly, cutting out a step, thus increasing overall efficiency?
Zinc is used as a catalyst to remove hydrogen from water leaving zinc oxide. The heat come from solar radiation.
Zn + H2O + heat --> ZnO + H2
The hydrogen can be used as fuel producing only water:
2*H2 + O2 --> 2*H2O
The zinc oxide is reduced to Zn using heat from solar radiation:
2*ZnO + heat --> 2*Zn + O2
The cycle repeats and the zinc is reused continuously.
Zinc will be needed initially and it will be need to be replenished on occasion, but compared to the world's consumption of zinc (12 million tonnes per year) it's probably quite small.
Remember as well that the pollution produced by the additional production of the zinc will probably be offset by reduced emissions from burning hydrogen instead of gasoline.
All in all, I think they've got a good plan to produce hydrogen in such a way that the environmental impact is minimal and should be greatly offset by reduction in other areas.
I void warranties.
Seriously there's so much of it around why not use it up for something?
This article from 2005 on a different ZnO-Zn process may be of interest:
Zinc: Miracle Metal?
The SolZinc process described there uses carbon in the ZnO reduction, and works at 1200C, compare with 1650C = 4000F for the prototype in this post.
Key quote:
Mobile fuel cell: There are already projects to run vehicles such as buses on zinc-air fuel cells. If these could be moved down to cars, the results could be quite impressive; a vehicle using 250 Wh/mile would require only 179 grams of zinc (2.74 moles) per mile. Zinc is a reasonably dense metal at 7.14 g/cc; solid zinc would yield about 40 miles to the liter, or upwards of 150 miles per gallon (powdered forms would not be quite so energy-dense). The carbon monoxide would also be surplus in this scenario.
The actual available energy (electricity) from a Zn-air fuel cell is several times as great as what can be obtained from the same chemical input of gasoline to an internal combustion engine. The metallic zinc contains about 90% as much energy as the input carbon, and it can be converted to motion with very high efficiency. It appears likely that a solar-mediated zinc reduction process using coal could power 3.5 times as many vehicle-miles as a conversion of coal to liquid fuel.
Infrastructure is the questionable issue. If we ship zinc metal out as fuel then we have to ship it back for recycling, or get the zinc oxide to another solar plant. (If we ship hydrogen we have to manage the bulk.) But we did it with coal.
>A mechanical engineer working out of the University of Delaware
Huh? They kicked him out and he's still working there? Wandering around the edge of campus or something?
Or did you mean:
A mechanical engineer working at the University of Delaware
Must have been a typo . . . .
read previous comment about formic acid. it is _the_ solution to the hydrogen storage problem.
A lot of fertilizer (ammonium nitrate) is made from oil or natural gas purely because that's the easiest way to get hydrogen. There are a lot of other industrial uses for hydrogen which currently mean chemical plants are close to oil refineries and natural gas pipelines.
As a fuel hydrogen gas is a pain to store and transport in comparison to butane, propane etc or a liquid fuel, but if you can make it at sane costs where you need it then you don't need to store or transport much of it.
The zinc gets reused, and no form of mining is "clean", not even for Uranium, not even for sand although it has less impact than most. You've been fooled into a bullshit circular argument where the only way out is making everything out of driftwood or fallen branches.
Here is a proposal posted on the National Renewable Energy Lab's website ( http://www.nrel.gov/hydrogen/pdfs/development_solar-thermal_zno.pdf ). It discusses in further detail the process by which ZnO is decomposed into Zn metal and oxygen, using the Zn metal to react with water to form ZnO and H2 gas.
is fueling vehicles.
Hydrogen sucks for fueling vehicles. It is difficult to compress sufficiently to get a car to have a reasonable range, and brittlizes metals used for storage tanks, causing them to leak. Hydrogen will accumulate in garages and houses, with the result that houses either begin looking like the Hindenburg if they simply catch fire, or a bomb if the hydrogen mixes with the air in the right (wrong) proportions.
IOW, this article has attached to it a "So what?" If we want to use it to store solar power for overnight commercial power for sale, we STILL have to compress it, which is STILL expensive in terms of energy, but it could be done. But solar-thermal power generation with the "thermal" part stored in the heat of fusion of molten salt is much easier. Sooo... what?
I ran across this paper on nano scale production of zinc oxide by a laser ablation method. If the ZnO is being used as a catalyst, nanostructures are useful for their increased surface area.
This might be useful for those amateur chemists wanting to build their own at home.
Yang, Li, Paul W May, Lei Yin, and Tom B Scott. 2007. “Growth of self-assembled ZnO nanoleaf from aqueous solution by pulsed laser ablation.” Nanotechnology 18(21):215602. Retrieved April 5, 2012. http://www.chm.bris.ac.uk/pt/diamond/pdf/drm17-931.pdf
actually i checked the msds out of interest, it has a 3 for health and a 2 for fire but a 0 for reactivity. seems like it would work.
apparently an issue is that the patents on formic acid fuelcells are held by tekion and university of urbana champane, not sure how much
this restricts implementation. they developed palladium as a catalyst but its it still an expense that may be the a significant constraint.
I've said for years that there's nothing wrong with electric vehicles that a batter that lasts twice as long at half the price wouldn't fix. That's actually a 4X improvement, approximately, but we've improved a bit over the last few years.
Long term, I think Lithium-Iron (LiFe) batteries are going to win the automotive market - a little less energy density(though they're working to fix that, of course), but they degrade so much slower that after the first year they actually hold more charge.
I don't read AC A human right
It is self sustaining as long as it's being sustained by sunlight.
When water is heated above 800degrees celcius it dissociates into its component parts, the only trick is separating the oxygen and hydrogen before they cool down and re-combine. The EU is funding research into this: http://www.hydrosol-project.org/
I'm not a chemist, but why not deposit the Zn vapor onto a surface and sell it to produce Zn-metal batteries?
Would this provide an electricity storage source that is more dense than Hydrogen? Since the generators are distributed, then the Zn-battery plants could be built near the furnaces and the results distributed in local markets.
Something similar to the Better World battery swap stations could replace depleted batteries with fresh ones and the depleted batteries could be sent back and refined in the furnaces.
As a distribution matter, wouldn't this be somewhat less problematic than piping low-density Hydrogen around the community?
I always get the shakes before a drop.
The hydrogen is obtained by splitting water into hydrogen and oxygen using solar energy. When the hydrogen is burned, the exact same amount of water is recreated using the exact same amount of oxygen that was released when the hydrogen was produced. Together with heat it is released into the atmosphere. The net effect is that sunlight is used to make water evaporate. The process does not add water to the water cycle. Burning fossil fuel does.
see ozmanjusri's comment http://hardware.slashdot.org/comments.pl?sid=2766393&cid=39581439, but if you also have CH4 (biogas from cow shit?) it becomes even easier because you can start with a methane reformer.
You can burn a bit of the natural gas to get the temperature up to 800C.
Can anyone point out if there's anything wrong with:
1. 4CH4 + 2O2 + 2CO2 -> 6H2 + 6CO + 2H2O (exothermic, high temperature high pressure, autothermal reforming)
2. condense the water out? or somehow drive the water gas shift reaction so that you've got the right proportions for CO and H2
3. 6CO + 6H2 -> 3 CO + 3 CH3OH (high temperature high pressure with catalyst)
4. condense the methanol out or use it for the (extremely dirty?) Fischer-Tropsch process to make gasoline.
To be, or not to be: isn't that quite logical, Slashdot Beta?
I think this has been done before. Check out the hydrosol project: http://www.hydrosol-project.org/ They built a device to produce hydrogen using a "solar reactor" several years ago. How is this new device different?
The Sulphur iodine cycle is a far better solution because it operates at 850C rather than 1700C for this Zinc cycle.
http://en.wikipedia.org/wiki/Sulfur%E2%80%93iodine_cycle
1700C is very very hard on materials exposed to oxygen and air, and practical limits of economic mirrors limit you to about 2500x solar concentration so the efficiency of your solar receiver radiating 900kW/m at 1700C drops to 60% at optimal conditions and normally far less depending on solar insolation (typically ranges 0.3-0.9kW/m during day).
Why is carbond dioxide an 'undesirable emission'?
Because of so-called 'man made global warming'? Sorry - 'climate change'?
www.climatedepot.com
All of this is true, and it would be great to crunch some numbers some time to find out what the absolute efficiency is compared to hydrocarbons...
However one point that everyone seems to be missing is that in transport, weight is more important than volume... the more your lugging around the less efficient the entire vehicle is, so forgetting the chassis for a moment, you can consider the vital parts that define the driving system of the vehicle to be the engine, and battery/fuel... Now you can compare hydrocarbons and hydrogen more effectively... with an electric car you have a significantly smaller, lighter, more efficient, and usually more powerful engine, so already you have a large volume available compared to a combustion engine....
The bottom line when it comes to cars is... a) can i fill it up enough to go X miles, and does the combination of engine, and battery components take up significant more volume than the petrol equivalent. b) what does it weigh? ...the efficiency of this system is also comparable by weight, because your taking it with you.
Is this cheaper/more efficient than electrolysis?
Solar cell+2 wires+water+capture vessel = clean, cheap hydrogen anytime there's any light at all. Scales infinitely. Can use any bulk water.
There must be some reason this is better? It's certainly not cleaner...
-Styopa
Technically it is true alcohol has only 70% of the energy of diesel or petrol per kg or per liter. But it stores easily in room temp, alcohol tanker trucks, alcohol pumping stations exist, and all of them are grandfathered out of any new hazardous materials handling laws. All new fuels will face significant hurdles in getting past the regulations. In fact, you can't transport handle petrol/diesel under present day haz mat rules economically. That and the liability case law and precedents set up a huge cost of entry barrier to anything trying to displace these fuels.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
Water vapor is the most dangerous greenhouse gas. Ignorance abounds in the land of "clean energy".
This could be a very big thing, IF it works. If the test proves that the furnace produces enough hydrogen to warrant further development, and IF that works out, we could end-up not needing oil. That would not only benefit the environment, but it would also change the politics of the middle east completely. Interestingly enough, I wrote a Fantasy novel which required a renewable source of hydrogen to power a fuel cell on a non-fossil fueled boat. Back in 2002 when I did the research into this, I found a bacterial hydrogen generator project which used a genetically altered form of algae to produce hydrogen via photosynthesis. The book is more Fantasy than Sci-Fi, because the boat is sent back in time to 1813 to commit the perfect crime. To steal gold from Napoleon as an act of war committed by the Royal Navy. You can get the first half of Napoleon's Gambit free at, http://napoleonsgambit.com/
Let the Free Intelligent develop occur and miracles can happen. There ARE ways that have and will have to produce clean, safe and plentiful energy. Get the bureaucratic idiots out of the way and reduce the overbearing suppression of new technology by entrenched industry giants and we can make this a more viable planet; and just maybe the Human Species and Planet Earth will survive!
Skip Stein Free Agent Management Systems Consulting, Inc. http://www.msc-inc.net www.linkedin.com/in/skipstein
My buddy and I did this in chemistry class in 1981, using a bunsen burner. Then we made nitroglycerin. When it turned red, we rushed it outside where it blew up the flask. We have enough hydrogen to last basically forever. This could be the key to switching from petroleum.
Nothing to see here but us trolls...move along...
There may not be many welders hanging out here, but trust me, Zinc fume is nasty. It won't kill you, but it's Not Good to breathe in.
You can't tell me that this thing recovers 100% of it's catalyst.
Well, a Volt isn't exactly #5, but good catch. I was picturing a pure electric vehicle with a small hitch and specialized power plug in the back; that way you avoid the expense of the engine - in both cost and weight, for normal trips that don't need it. And #6 would fix you right up.
So let's add one. I ordered them for what I saw as practicality/likelihood.
7. Buy a multi-fuel vehicle; plug-in hybrid of some sort if you make a lot of long trips
In your case, I'd consider utilizing mass transit - train or bus into city core; walk the rest of the way. I'd prefer a city core optimized for foot traffic - I live in the upper north, so to me this means skybridges and perhaps even slideways in the larger city centers. At an easy 3mph, a human can travel a mile in 20 minutes. If you figure that it takes 8 minutes to get to your car, start it up, get out of the parking spot and lot onto the road, then drive at 10mph average, then take another 8 minutes to park and get to the final destination, that's 21 minutes. With slideways doubling the walking speed to 6mph, that's more like 1.5 miles where going by foot is actually faster.
By the way, have you considered the cost of your commute? That living closer to your work might be better? Assuming you work 5 days a week, that's 25% more time, 500 extra hours a year dedicated to your job, plus fuel, plus car wear, etc... I believe that it's unsustainable for most people; the suburbs are eventually going to die. Note: This means attention needs to be paid in cities, building GOOD apartments and condos and such.
I don't read AC A human right
Scuba Tanks? Really? They're not that common on boats and aren't optimized for holding hydrogen. It'd be like trying to hold sand in a wire collander intended to drain pasta.
I mentioned it working better with a massive cylinder at a factory - economy of scale. scuba tanks would actually be smaller than the ones mounted in a car.
I don't read AC A human right