Silicon Nanoparticles Could Lead To On-Demand Hydrogen Generation 163
cylonlover writes "Researchers at the University of Buffalo have created spherical silicon nanoparticles they claim could lead to hydrogen generation on demand becoming a 'just add water' affair. When the particles are combined with water, they rapidly form hydrogen and silicic acid, a nontoxic byproduct, in a reaction that requires no light, heat or electricity. In experiments, the hydrogen produced was shown to be relatively pure by successfully being used to power a small fan via a small fuel cell."
Honest, Officer (Score:4, Funny)
I wasn't having an illegal campfire on the beach. It was the sand reacting with the seawater.
Re:Honest, Officer (Score:5, Funny)
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This reminds me of yesterday's article - cooling with lasers.
Myself, I once started a forest fire, being careless with an ice cube.
Re:Honest, Officer (Score:4, Informative)
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The officer would probably get tipped off when your pants caught fire.
The key question becomes (Score:5, Insightful)
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Re:The key question becomes (Score:5, Insightful)
Even if it is neither of those it can still be a win if it is non-toxic or easy to dispose of.
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Re:The key question becomes (Score:5, Informative)
Where does silicon come from? Silicon dioxide, a.k.a. "sand". How tightly is it bound? Very, very, very tightly. Indeed, a whopping 910.86 kJ/mole. So it requires at LEAST this much energy to turn sand into silicon and oxygen, except that one cannot electrolyze or reduce it until it is molten, so add to this enough energy to melt sand, after raising its temperature to some 1500 C. Then, one has to engineer "nanoparticles" out of the purified silicon metal. At a guess -- only a guess, of course -- this involves heating the silicon to the vaporization point and either vapor depositing it on a suitable substrate and scraping off the nanoparticles or spraying silicon vapor into a suitable medium that causes it to condense out small particles and then filtering or otherwise separating out the 'nano' particles from those that are merely small. Sounds like more energy to me.
At the end of the day, you can get at most the 250 or so kJ/mole back from the hydrogen gas produced after the silicon nanoparticles steal the hydrogen back from water. I think it would be an absolute miracle if it this is as much as 10% of the energy invested in making the nanoparticles, and the energy costs are probably at most half of the total manufacturing costs. Down to 5%. Multiply by roughly 50% again (efficiency of fuel cell).
This "Fermi estimate" of the probable economic efficiency is on the order of 2.5%, then, compared to the cost of just buying electricity or any other form of concentrated energy. Even if I'm too aggressive in my pessimism, 10% is a pretty safe upper bound. I'm not seeing this as a game changer. Gasoline or other hydrocarbons are still the gold standard for readily available energy density at ballpark 35 MJ/liter, and don't require investing 20 times the energy eventually recovered in their preparation.
rgb
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Because Obama hasn't given me a call yet to make me the offer, I suppose. I'm not sure I accept it if he did -- it has to be a thankless job these days and I'm enough of a climate skeptic to think that energy resources need to have net positive present cost-benefit before implementing them on a broad scale. Until then research and even prototyping is lovely and worthwhile, but no large scale implementation at a loss until it results in something at least cost-competitive with existing fully developed reso
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So... robotic orbital solar furnaces, dropping unmanned capsules of water ignition material down to Earth?
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No one makes nanoparticles in large quantity by vapor deposition. You react the silicon to a suitable precursor and then reduce it gently. It's a very high yielding reaction. Silicon tetrachloride would be one example of a precursor you could use (I think there's a few others - there's a guy in my lab who makes a lot of silicon quantum dots).
The big question is how easy it is to go from silicic acid back to nanoparticles - if it can be done electrochemically and relatively efficiently then what's been disco
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May seem like a stupid question, but are these silicon particles consumed during this process?
Re:The key question becomes (Score:5, Insightful)
Remember, there is energy extraction, and energy packaging. Petroleum is a huge win, because it is both - refining is relatively cheap, and it packages the result. This is not energy extraction - there is a large input, but it makes a convenient fuel cell package that gets around the problem of storing hydrogen. Since hydrogen is very chemically reactive, it's a big problem in having a hydrogen based energy chain.
The input cost is essential, especially the theoretical efficiency, against other forms of energy storage. This would include how stable the nano-particles are, because water is ubiquitous.
However it could be great for renewables, because the onsite wind farm or what have you, could be used to generate the silnaparts and this stores them. It could also be good for nuclear power, which runs continuously, and thus reduce the need for peak capacity, which is heavily carbon dominated. Even if not very efficient it could significantly reduce carbon footprint, because there would be no concern about the major problems of current bulk energy storage: gravity is environmentally destructive, and batteries have rather low cycle limits.
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One wonders if the irony of your statement was intentional, or whether you were even aware of it.
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A randwanker is someone who thinks they understand and have destroyed the logical argument for libertarianism.
Really they are mentally masturbating on their strawman.
There are million of them on /.
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Comment removed (Score:4, Insightful)
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All the silicon in the world was produced by releasing oxygen into the atmosphere when it was refined. No danger there.
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No need to, the oxygen wasn't in the atmosphere, it was bound to the hydrogen in the water molecules. Water is burned hydrogen, so this oxygen was already "lost".
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No need to, the oxygen wasn't in the atmosphere, it was bound to the hydrogen in the water molecules. Water is burned hydrogen, so this oxygen was already "lost".
Except this method doesn't release the oxygen. The oxygen gets bound into the acid. So when new water is created from the burned hydrogen, it comes from the atmosphere (or some oxidizing agent). With a net "loss" of oxygen to the acid.
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I would suggest that instead of mining more silicon dioxide from beaches, you use the waste product as your feedstock for the silicon nanoparticle production. (in bulk) - since you're applying enough energy to get it up to 1500 C anyway, you're going to disassociate that oxygen, (and probably release it as a waste product). Thus, in NET, no oxygen is removed from the atmosphere.
(obviously, the process won't be perfect, so there will be small losses - likely oxygen being bound-up with other reactants during
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Except this method doesn't release the oxygen. The oxygen gets bound into the acid. So when new water is created from the burned hydrogen, it comes from the atmosphere (or some oxidizing agent). With a net "loss" of oxygen to the acid.
The wiki article on Silicic acids [wikipedia.org] seems to suggest that in an aqueous solution, the silicic acids readily lose water to form silica gel.
So it might be that most of the oxygen is returned to the water, leaving some small packets of silica gel labeled "do not eat" littering the roadway.
Re:The key question becomes (Score:4, Insightful)
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The oxygen in the acid came from the water. The oxygen that's coming from the atmosphere to to combine with the hydrogen when burning it becomes water - specifically, water vapor which goes off in the flame to mix with the rest of the atmosphere... where it can then be used by plants for photosynthesis.
For the acid itself, if you'll read the article, you'll see that it's silicic acid. You can then look up 'silicic acid' on Google, which took me to the Wikipedia page for it, where it mentions that silici
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[snip]So, it doesn't look like disposal of the acid would be much of a problem.
And if it does become a problem, we'll just import some silver-backed gorillas to deal with the acid.
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The chemical pathway followed by oxygen through carbon is much more easily recovered, and that is done naturally, through photosynthesis. (though - the rate of oxygen recovery is somewhat lower than our rate of production).
In this case, there simply is NO natural recovery pathway.
Unless some fantastic genetic engineering process is able to create an organism capable of breaking down the silicon waste product into components, releasing the oxygen.
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In this case, there simply is NO natural recovery pathway.
Unless some fantastic genetic engineering process is able to create an organism capable of breaking down the silicon waste product into components, releasing the oxygen.
They're called phytoplankton. Silicic acid, along with Nitrate and Phosphate, are inorganic nutrients which phytoplankton turn into organic nutrients, and so essentially form the base oceanic of the food chain.
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I don't believe you've taken into consideration the oxygen released from converting Silicon Dioxide into Silicon and Oxygen. Looking up Silicic acid, it's a generic term for a family of related acids. Looking at the 4 simplest ones, I get the following equations.
Si + 3 H2O => H2SiO3 + 2 H2
Si + 4 H2O => H4SiO4 + 2 H2
2 Si + 5 H2O => H2Si2O5 + 4 H2
2 Si + 7 H2O => H6Si2O7 + 4 H2
For all of the above equations, each Silicon atom will result in the generation of 2 hydrogen molecules (4 atoms). Which re
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Given that the silicon will be extracted from SiO2 or silicates, the process of creating the nanoparticles in the first place will release oxygen bound to the silicate raw materials, the oxygen balance will even out.
Didn't think of that. Thanks!
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And what's the weight ratio of the particles to the amount of hydrogen produced by them.
Re:The key question becomes (Score:5, Informative)
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Interesting. However, how "reusable" is it? I'm guessing it's not very which will just add to the expense, meaning that ultimately this is a pretty niche product.
Re:The key question becomes (Score:4, Insightful)
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Re:The key question becomes (Score:5, Informative)
Indeed. I work for one of the major "silicon crushers". Converting sand to metallurgical grade silicon (97%+) takes an arc furnace, lots of electrical power required. Then comes grinding and classifying it and most processes deliberately spray the dust with water to put an oxide layer on the particles to prevent a dust explosion.
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Re:The key question becomes (Score:5, Interesting)
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Why are they using a generator to charge the ipad? A 13W solar panel and battery that can charge the ipad several times over cost me $150 and will supply power virtually forever (the battery will eventually run out of charge cycles, but even then you can use the panel output as long as the sun is shining). My panel even provided a useful level of charge in the middle of Hurricane Sandy, so it's not like a pressure system would leave them without power. Slightly more efficient ways to get stored power to the
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Because the big ass generator can run the dishwasher, dryer, big assed radio AND charge the iPod. The solar panels can only charge the iPod.
But yes, the military is looking into portable (in the military sense of the word) solar / battery set ups that can run a small town.
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And you have to look at it like dehydrated food. In lots of situations you have easy access to water even if you have no access to fuel or food. So for instance when backpacking you carry dehydrated food since the water makes up most of the weight while being easily accessible in the wilderness.
So while you might need 28 gallons of water to deliver 1 gallon equivalent of gasoline with this silicon system--it's probably pretty easy to find 28 gallons of water nearby--especially if potability isn't a conce
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I'm hoping this doesn't turn into another "butbutbut but it still takes more energy to make than it gives back!" argument. The key here is making the stored energy portable. Gasoline takes a lot more energy to drill, transport and refine than it gives back, but the end product is very portable so the premium is worth it compared to stuff like coal or natural gas that (presumably, I don't really know) takes less effort to get to the end product. However, coal is pretty impractical for portable applications l
Re:The key question becomes (Score:5, Informative)
It just has unfortunate side effects: it is killing us, and killing our ecosystem, which we are rather dependent on, there being no other garden worlds.
Re:The key question becomes (Score:5, Funny)
If your pathetic genome had better redundancy and error correction you wouldn't care about the radiation.
Oh wook at da poor wittle hue-mans, can't come out an pway in the milky way because them scawed for cosmic rays. Have fun being grounded dork!
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plus you can take all that off peak wind power and similar to power the plants that create the nano particles thereby reducing the risk to investors on both sides.
I guess the concern comes down to, how clean must the water supply be? It would be very valuable if it can work with different level of containments up to and including salt water
Re:The key question becomes (Score:5, Informative)
Um, no. It typically takes around 4MJ/L (just over 1kWhr/L) to refine petrol, while the energy content is 35MJ/L. Drilling and transport add a little to that, but it's negligible compared to refining it. If it wasn't so, using it would have a net negative impact on our energy supply and no-one would use it.
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The vast majority of "fossil fuels" on Earth are biotic in origin. Abiotic hydrocarbons do of course exist, and are plentiful on Titan, but are relatively rare on Earth.
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has every advantage of gas (liquid can be pumped, etc)
... unless you live in Minnesota or some other cold climate.
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Gas is stored underground at gas stations. Store water underground and it's pretty easy to maintain it at a temperature above freezing... even in climates much colder than Minnesota.
It's also not too difficult to keep it as a liquid using other methods ranging from passive to active.
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I think you're phrasing that backwards (Score:2)
Don't expect to be able to just top up your car with water and drive a few thousand miles on a single silicon cartridge. Water stores too little energy to ever be useful as a fuel, nor can it be "converted" in any conventional sense. The best we can do is pump in a lot of energy and create a fuel from it, as with electrolysis, but the energy has to come from elsewhere.
In this case, all the energy comes from the silicon nanoparticles, and the water just releases that energy as unbound hydrogen. Since nothing
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The next most important ones becomes what do we do with the hydrogen?
It embrittles metal, it seeps through everything, if it powered cars garages would have to be built in such a way to allow it to escape, hydrogen power has lots of really fundamental issues.
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It embrittles metal, it seeps through everything, if it powered cars garages would have to be built in such a way to allow it to escape, hydrogen power has lots of really fundamental issues.
That's why you want on-demand production.
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Efficiency (Score:2)
Exactly. The article claims poor efficiency:
The downside is the significant amount of energy and resources required to produce the smaller silicon particles. This would make the particles expensive and likely rule them out for widespread use in powering consumer electronic devices – at least initially. However, the researchers say the technology could find applications in situations where water is available and portability is more important than cost, such as camping and military operations.
So i
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Most people consider the military a tad more upscale than 'a parlor trick'.
(For my next treat - a fully assembled nuclear weapon!!)
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Nah, I'd still put this battery in the parlor trick category. It makes lots of hydrogen, but at an enormous cost! Tada!
It might replace butane fuel cells because it could be made smaller (an important military consideration), but it isn't a game changing technology yet. It could be though. If some wizard somewhere figures out a more efficient creation process. But hey, any new energy technology is another time at bat, another opportunity for mankind to finally hit one out of the park and get clean, n
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I would also ask if the particles are "used up" in the process. The article doesn't say and I'm not familiar enough with the chemistry to know.
If they are not used up then you have a whole different equation. A one time high cost depreciated over some years of use could be a huge win.
Close but no cigar (Score:2)
No; it's how long can they run before being degraded by contamination? If it takes six-sigma water purity to prevent crap from interfering with the reaction, then it's more novelty than breakthrough.
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Gimme a match, quick! (Score:4, Funny)
Silicon Nanoparticles Could Lead To On-Demand Hydrogen Generation
That's some serious R&D by the whoopie cushion industry.
Why "silicon nanoparticles"? Just add water ... (Score:5, Funny)
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Versions using magnium-iron alloys are readily available: https://en.wikipedia.org/wiki/Flameless_ration_heater [wikipedia.org]
10nm particles... (Score:5, Insightful)
What's the health impact of these getting into the ecosystem? Pass right thru a human? Cause serious disease? What happens when it hits the water IN a human? If this becomes in any way widespread these are going to be issues.
What's left after the reaction? Must the water be pure or can we produce power from dirty water and do what with what's left? Could this be used to clean dirty water by simply using the water for power? Is oxygen also produced from this - I'd think so right since water is H2O. Are the particles completely consumed in the reaction? No reuse? How much water is used in the manufacturing process to create these particles? What are the waste byproducts for the process of creating these particles?
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What's the health impact of these getting into the ecosystem? Pass right thru a human? Cause serious disease? What happens when it hits the water IN a human? If this becomes in any way widespread these are going to be issues.
Says the guy who likely starts up an internal combustion engine with a lead acid battery and dumps the toxic exhaust directly into the ecosystem.
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In a production system, the particles will probably be stuck onto a screen or surface to prevent them from being washed away along with the waste. A system that requires constant addition of the catalysts or a batch reaction that works for a few minutes then requires reconfiguration of the system is just not going to fly.
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From the way it sounds, I don't think it's ICE-9.
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Um, I think that's us. You know, the crowd. With wisdom and all that.
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No actually I do not see answers to my questions so clearly as you and apparently others do.
No health impacts from this? So then you'd be willing to swallow it? Get it in your hair? Eyes? Lungs? Food? How about a gel capsule down the hatch? Did you see anything in either linked article that mentions this? I didn't. I see what is supposed to be a harmless acid and hydrogen mentioned as byproducts, nothing more. Hey is Graphene okay to swallow? Buckyballs? You might be surprised. You might not want to swallow
Still no free lunch (Score:3)
From TFA ...
Though it takes significant energy and resources to produce the super-small silicon balls, the particles could help power portable devices in situations where water is available and portability is more important than low cost. Military operations and camping trips are two examples of such scenarios.
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I wonder if this could help power a probe to drill through the ice on Enceladus...
There's No Mention of the Catalyst? (Score:2)
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It's completely stupid anyway.
Consider when you burn 2H2 + O2 you get 2H2O + heat. That means you need energy to go from H2O to H2 + O. Heat, current, something.
Catalytic water reaction: Will eventually freeze itself. It may reach absolute zero; probably not nearly. Will require heat input.
Non-catalytic water reaction: will take as much energy to produce the fuel as is required to break down the water, at least. Really, more energy in (and lost) than energy out. Catalytic recycling of the reac
Seemingly good by-product (Score:2)
Looked up silicic acid and, for once, doesn't seem to want to destroy the environment or cause cancer, that we know of yet.
Great (Score:4, Funny)
Re:Great (Score:4, Funny)
Just try to keep your cat out of it, alright?
borohydride? (Score:2)
What's the advantage over Borohydride?
http://en.wikipedia.org/wiki/Borohydride [wikipedia.org]
It's still about net energy (Score:3)
How much energy does it take to make the stuff, transport it, dispose of it, and so on? It may prove to be an adequate energy carrier if it's cheap enough AND we have enough cheap electricity to make use of it, which might happen if we actually get thorium-based nuclear power AND we can solve the engineering problems involving the use of hydrogen in any metallic machines.
Not a bad technology if it's more energy dense by volume and cheaper than current batteries though.
Film at 11. (Score:2)
What if a bunch of these were dropped into a deep part of the ocean? Would bubbles of hydrogen begin to rise to the surface, continue to rise, and eventually convert all the oceans into acid and free hydrogen?
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Bad trade (Score:2)
Oh yes, water won't burst into fire. But water is corrosive. It causes rust.
This is basically only useful in two situations:
1. Some moron is too scared of hydrogen fires to understand it is safer than gasoline.
2. Situations where we can not take the standard precautions against fire.
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you don't understand that H2 is very hard to contain, its the smallest of the gases and if it escapes, together with Oxygen produces a very explosive/inflammable mixture.
you need very well constructed (and heavy) containers and very good transfer methods (fool proof).
Also, hydrogen is also corrosive and suffer from migration on metals and other crystalline structures (check wikipedia [wikipedia.org] for more info.)
Compared with the propane gas, its a lot harder to work with and, specially, long term maintenance.
Water, you
oxygen (Score:2)
If only we had an easy way to make an oxygen free environment to store our silicon nanoparticles prior to wetting them...
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No, H2 gas is going to react with O2 at ground level almost immediately, it's not going to get all the way up into the ozone layer.
Ozone itself is unstable, it only lasts a few hours at most before decomposing. We still have a ozone layer because it is being created constantly.