Beta

Slashdot: News for Nerds

×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Silicon Nanoparticles Could Lead To On-Demand Hydrogen Generation

samzenpus posted about a year and a half ago | from the just-add-water dept.

Power 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."

cancel ×

163 comments

Honest, Officer (3, Funny)

mbstone (457308) | about a year and a half ago | (#42689697)

I wasn't having an illegal campfire on the beach. It was the sand reacting with the seawater.

Re:Honest, Officer (-1)

Anonymous Coward | about a year and a half ago | (#42689751)

Let's form proactive synergy restructuring teams.

Re:Honest, Officer (-1)

Anonymous Coward | about a year and a half ago | (#42689833)

FUCK off.

Re:Honest, Officer (-1)

Anonymous Coward | about a year and a half ago | (#42690189)

I'm so, so, so very sorry. Please don't be mad at me. I am bound to a wheelchair in my real life and this website is like my window from which I see the world. I did not mean to offend you with my statement, perhaps the small area which I traverse as become lonely and I just wanted to feel companionship. The type you would find on a team.

Again, I apologize anything that caused you to use the F word against me must have originated in misunderstanding.

Re:Honest, Officer (0)

Anonymous Coward | about a year and a half ago | (#42691057)

Off is short for Ofilia, his mom's name. He wasn't offended he was thanking you by giving you a gift.

Re:Honest, Officer (4, Funny)

slashmydots (2189826) | about a year and a half ago | (#42690071)

Having a fire on the beach and having the beach on fire are two completely different things

Re:Honest, Officer (2)

Jeremiah Cornelius (137) | about a year and a half ago | (#42691497)

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 (4, Informative)

richtopia (924742) | about a year and a half ago | (#42691073)

Keep in mind that hydrogen burns clear, so it will be pretty hard for the officer to discover the fire

Re:Honest, Officer (2)

tilante (2547392) | about a year and a half ago | (#42691329)

Flames of pure hydrogen are very hard to see - however, when there are impurities present and also burning, the flame can be very easy to see. See, for example, photos of the Hindenburg burning. Using sea water, the flame would likely be very visible. See, for example, this video showing sea water being burned using a different process for extracting hydrogen from it: http://www.youtube.com/watch?v=e8utkoK2DhA [youtube.com]

The key question becomes (4, Insightful)

Stirling Newberry (848268) | about a year and a half ago | (#42689703)

How much energy to create the silicon nanoparticles.

Re:The key question becomes (3, Insightful)

jcr (53032) | about a year and a half ago | (#42689719)

If it's less than the energy used to make conventional, disposable batteries of equivalent power, it's a win. Even if it's more costly than that in energy terms, it could still be a win from a weight to power ratio standpoint.

-jcr

Re:The key question becomes (4, Insightful)

snarkh (118018) | about a year and a half ago | (#42689747)

Even if it is neither of those it can still be a win if it is non-toxic or easy to dispose of.

Re:The key question becomes (1)

jcr (53032) | about a year and a half ago | (#42690253)

That, too.

-jcr

Re:The key question becomes (5, Informative)

rgbatduke (1231380) | about a year and a half ago | (#42691255)

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

Re:The key question becomes (5, Insightful)

Stirling Newberry (848268) | about a year and a half ago | (#42689853)

Both this question and the next one roll into what is called the "Life Cycle Analysis" the net output per unit input.

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.

Re:The key question becomes (0)

rot26 (240034) | about a year and a half ago | (#42690327)

because water is ubiquitous.

This will not necessarily always be the case. And somewhere, some bureaucrat is already scheming to figure out how to tax water.

Re:The key question becomes (-1, Flamebait)

Stirling Newberry (848268) | about a year and a half ago | (#42690405)

Your comment is beneath contemptibly stupid. While potable water can be in short supply, water is virtually everywhere: sea water, ice, even in the air.

The second part shows you are a gun-nut randwanker. Don't you have the next chapter of your book on how Obama is a muslim marxist born in Kenya to capitalize?

Re:The key question becomes (1)

Redmancometh (2676319) | about a year and a half ago | (#42691167)

How does that make him a "randwanker," and wtf is a randwanker. His comment didnt seem biased at all. Your just reaching for something to get your pannies in a bunch. People like you make me nauseas. Also doesnt sales tax apply to bottled water already?

Re:The key question becomes (0)

Anonymous Coward | about a year and a half ago | (#42691487)

Calm down there, geek. Don't go shooting up a school or anything. How deep into ideological bullshit must you be to think you can profile the guy based on one silly quip? You sound like someone with severe mental issues.

Re:The key question becomes (1)

LordLimecat (1103839) | about a year and a half ago | (#42691553)

One wonders if the irony of your statement was intentional, or whether you were even aware of it.

Re:The key question becomes (2, Interesting)

Culture20 (968837) | about a year and a half ago | (#42689943)

Then the question is "how much energy does it take to crack the oxygen back out from the acid?" Start burning that hydrogen everywhere for decades and we'll have a little less oxygen in the atmosphere. Ordinary water cracking leaves the proper amount of H and O for future reacting.

Re:The key question becomes (3, Insightful)

jcr (53032) | about a year and a half ago | (#42690271)

I don't think you have a grasp of the scale of the earth's atmosphere. This might be an issue for people aboard a space station, but on earth it's insignificant.

-jcr

Re:The key question becomes (2)

dave420 (699308) | about a year and a half ago | (#42690393)

Like, say, the amount of CO2? Honest question.

Re:The key question becomes (1)

Culture20 (968837) | about a year and a half ago | (#42690987)

That's why I qualified it with "a little less". This isn't an "almost forever" technology like fusion or solar usable for millions of years. Pumping CO2 into the atmo is nothing compared to reducing available O2. With the exception of anaerobic bacteria and archaea, everyone likes oxygen, even plants (the CO2 variety of oxygen at least).

Re:The key question becomes (2, Informative)

Anonymous Coward | about a year and a half ago | (#42690689)

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".

Re:The key question becomes (2)

Culture20 (968837) | about a year and a half ago | (#42690845)

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.

Re:The key question becomes (3, Insightful)

daem0n1x (748565) | about a year and a half ago | (#42690791)

You're right, because internal combustion engines don't spend oxygen!

Re:The key question becomes (1)

Culture20 (968837) | about a year and a half ago | (#42690917)

We already have a process for putting that oxygen back into the atmosphere: plant photosynthesis. What is the process for this acid?

Re:The key question becomes (1)

daem0n1x (748565) | about a year and a half ago | (#42691041)

Why would we need a process? We take the oxygen from water, put it in acid. No atmosphere involved.

Re:The key question becomes (1)

tilante (2547392) | about a year and a half ago | (#42691565)

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 silicic acids (apparently there's a whole family of them): (a) tend to lose their water content easily, drying out to become silica gel and water; (b) have been suggested as a possible nutritional supplement to help prevent Alzheimer's, since they tend to absorb aluminum, which has been implicated in Alzheimers, and (c) in the ocean are used by diatoms to build their silicon-based 'skeletons'. So, it doesn't look like disposal of the acid would be much of a problem.

Re:The key question becomes (1)

Shavano (2541114) | about a year and a half ago | (#42689997)

The advantage would be storing the necessary energy in solid, chemically useful form and producing only non toxic byproducts. It won't be free or probably even cheap energy. And it's still only hydrogen that has to be reacted again at an additional energy loss to do work.

Re:The key question becomes (1)

LurkerXXX (667952) | about a year and a half ago | (#42689725)

And what's the weight ratio of the particles to the amount of hydrogen produced by them.

Re:The key question becomes (5, Informative)

R_Ramjet (994878) | about a year and a half ago | (#42689731)

Significant. From the article: "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."

Re:The key question becomes (1)

neokushan (932374) | about a year and a half ago | (#42689769)

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 (3, Insightful)

Stirling Newberry (848268) | about a year and a half ago | (#42689863)

Theoretical efficiency could be a great deal lower. We are about as good at producing nano anything as Assyrians were at producing steel.

Re:The key question becomes (1)

slashmydots (2189826) | about a year and a half ago | (#42690087)

I just bought a solar powered 1500maH battery pack with full sized USB port for powering or charging devices. I bet that's lighter, easier, safer, and results in less fire.

Re:The key question becomes (4, Informative)

ciggieposeur (715798) | about a year and a half ago | (#42690101)

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.

Re:The key question becomes (0)

Anonymous Coward | about a year and a half ago | (#42690543)

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.

Are you the sand people?

Re:The key question becomes (5, Interesting)

mapsjanhere (1130359) | about a year and a half ago | (#42690721)

This is strictly for military applications. The US forces in Afghanistan use 28 gallons of fuel to deliver one gallon of fuel to an outpost where a 3 gal/h generator charges an Ipod (don't laugh, that's from an US Army presentation). So, if I can charge my devices of a fuel cell fed by something like this silicon hydrogen generator I might save money not because it's energy efficient in production but energy efficient at the point of use. The reason they use silicon is that it gives you 1 gram of hydrogen per 8 grams of silicon. You could use other, cheaper, metals, but the weight ratio isn't as favorable (iron would require something like 20 to 1). As 1 kg of hydrogen gives you 127 MJ of energy, 1 kg of silicone powder gives you about 15 MJ. Compare that to a battery that gives you less than one MJ/kg, and you see the attractiveness if weight is at a premium.

Re:The key question becomes (1)

fizzer06 (1500649) | about a year and a half ago | (#42691023)

This actually makes sense if you assume Big Oil runs the US government and their goal is to fuck over the tax payers.

Re:The key question becomes (1)

RalphTheWonderLlama (927434) | about a year and a half ago | (#42691277)

Such as wind energy? So you don't have to run transmission lines everywhere? Make balls and truck them to the nearest railroad every so often. It could be a boon for expanding wind energy.

Re:The key question becomes (0)

Anonymous Coward | about a year and a half ago | (#42689777)

And what's the lifecycle that gives us more silicon nanoparticles from the resulting acid? Though it looks like the acid might be usable as a health supplement?

Re:The key question becomes (3, Insightful)

SJHillman (1966756) | about a year and a half ago | (#42689787)

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 like cars, lawn mowers or snowmobiles.

Water, on the other hand, has every advantage of gas (liquid can be pumped, etc) with additional advantages such as being much more renewable, much greater availability, much easier to get to and not being explosive if you decide to smoke while filling up. The only problem is that we haven't found a way to convert water into hydrogen fuel (which cannot be as easily stored or transported as water) at the point of use - either the pump or, better yet, whatever needs the fuel. If silicon nanoparticles can do that and you only need to swap in a new silicon nanoparticle cartridge every few thousand miles then it's well worth the extra energy to create them in the first place.

Re:The key question becomes (4, Informative)

Stirling Newberry (848268) | about a year and a half ago | (#42689879)

Actually the LCA of petroleum is excellent, that's one of the reasons it took over the world.

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 (0)

Anonymous Coward | about a year and a half ago | (#42690015)

Actually the LCA of petroleum is excellent, that's one of the reasons it took over the world.

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.

At least it doesn't turn us all into explosive, glowing mutants.

Re:The key question becomes (5, Funny)

VortexCortex (1117377) | about a year and a half ago | (#42690175)

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!

Re:The key question becomes (2)

rot26 (240034) | about a year and a half ago | (#42690437)

It's a feature, not a bug.

Re:The key question becomes (1)

Shivetya (243324) | about a year and a half ago | (#42689951)

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 (0)

famebait (450028) | about a year and a half ago | (#42689965)

Gasoline takes a lot more energy to drill, transport and refine than it gives back

Really?
Did you just make that up?
Source?

Re:The key question becomes (5, Informative)

DeathToBill (601486) | about a year and a half ago | (#42689983)

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.

Re:The key question becomes (1)

LifesABeach (234436) | about a year and a half ago | (#42690225)

I can't help but wonder how much it would take to ramp up to evalutate the process up to the level of generic production using 1kWhr/L as units of evaluation?

Re:The key question becomes (0)

Anonymous Coward | about a year and a half ago | (#42690293)

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.

How much energy did it take for plant and animal matter to be compressed and heated into oil? Just because nature did it for us for millions of years does not mean it made enough for us to keep using it, and when you take that energy and time into concideration in your equation, creating oil and then refining it into gasoline becomes a net loss of energy.

Re:The key question becomes (0)

Anonymous Coward | about a year and a half ago | (#42690489)

+1 internets to you sirrah. That is a factor that few take into account. I'm posting anonymously in your honor.

Re:The key question becomes (0)

Anonymous Coward | about a year and a half ago | (#42690643)

Right because it's "Fossil Fuel" all that plant matter on Titan was compressed to make it's methane based atmosphere. Oh wait.... * However, you argument still holds irregardless of your flawed understanding of the geological science of petroleum products. Entropy will kill us all in the end.*1

*http://www.amazon.com/Black-Gold-Stranglehold-Jerome-Corsi/dp/B003D7JVJS

http://www.amazon.com/Black-Gold-Stranglehold-Jerome-Corsi/dp/B003D7JVJS

*1 http://filer.case.edu/dts8/thelastq.htm
http://en.wikipedia.org/wiki/Heat_death_of_the_universe

Re:The key question becomes (1)

dkleinsc (563838) | about a year and a half ago | (#42689991)

has every advantage of gas (liquid can be pumped, etc)

... unless you live in Minnesota or some other cold climate.

Re:The key question becomes (0)

Anonymous Coward | about a year and a half ago | (#42690091)

Yes, I forgot that tap-water doesn't work in those nations.

But you just had to post something negative without thinking first, didn't you?

Re:The key question becomes (2)

SJHillman (1966756) | about a year and a half ago | (#42690517)

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.

Re:The key question becomes (1)

Shavano (2541114) | about a year and a half ago | (#42690011)

The water you use is safe. The nanoparticles are high reactivity and give off hydrogen when exposed to water, so they are not so safe.

Re:The key question becomes (0)

Anonymous Coward | about a year and a half ago | (#42690413)

The only problem is that we haven't found a way to convert water into hydrogen fuel (which cannot be as easily stored or transported as water) at the point of use

Sure we do: electrolysis. Problem being that it's very wasteful in both terms of transport and energy efficiency.

Re:The key question becomes (1)

jlebrech (810586) | about a year and a half ago | (#42689791)

The amount of energy required doesn't matter as long as it's made with clean energy and it's energy density is large enough.

You could then make nano particles in the Gobi desert with a solar station or with a LFTR nuclear reactor in china or india, or even create those in space.

Re:The key question becomes (1)

Stirling Newberry (848268) | about a year and a half ago | (#42689893)

That's a gross overstatement: this is competing with lithium batteries, gravity storage, and the like. It has to be better at creating applications for at least some range of circumstances than current energy storage. This could be a small set, or quite large.

Re:The key question becomes (0)

Anonymous Coward | about a year and a half ago | (#42689803)

1) Bomb Africa (directly or indirectly) to get raw materials.
2) Use and create toxic wastes to create the battery.
3) Exaust the battery to get toxic wastes.
4) Use toxics to trash the battery.

How can be worst than that?
Read point 1 again

Re:The key question becomes (1)

h4rr4r (612664) | about a year and a half ago | (#42690013)

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.

Re:The key question becomes (0)

Anonymous Coward | about a year and a half ago | (#42690153)

'it seeps through everything,...in such a way to allow it to escape...'

If it seeps through everything why do you have to 'allow' it to escape?

Re:The key question becomes (1)

Tapewolf (1639955) | about a year and a half ago | (#42690181)

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.

Re:The key question becomes (1)

Stirling Newberry (848268) | about a year and a half ago | (#42690237)

You have it reversed: the silnanparts plus water, represent the energy storage, when energy is needed, the two are combined, the resulting hydrogen is immediately used in a fuel cell, which liberates the energy. The silnaparts represent a potentially economically viable way of getting around the hydrogen problem. Thus one possible applicatio cycle would be: store energy from either renewable or nuclear source (both of which are not on demand) in the form of silnaparts, generate energy on demand from water. This would replace kerosene turbines and other forms of "peak" generation, which have terrible carbon density. The hydrogen is only around long enough to feed the fuel cell.

If this better than batteries or gravity storage, it could mean recapturing a great deal of lost power and lowering carbon emissions. However, some variables are not answered in the paper.

Re:The key question becomes (1)

gr8_phk (621180) | about a year and a half ago | (#42690527)

It seems obvious that the particles are an energy storage material. OK, since oxygen is used in the full set of reactions I suppose the particles are also acting as fuel. Regardless, they are consumed in the process. You start with water, and end with water, except a bunch of oxygen has reacted with these particles. IMHO this is still somewhat interesting.

Efficiency (1)

Weaselmancer (533834) | about a year and a half ago | (#42690867)

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 it's currently not much more than a parlor trick. You're not going to be filling up an electric car with silicon nanoparticles and water any time soon.

Re:The key question becomes (1)

foniksonik (573572) | about a year and a half ago | (#42691163)

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.

Gimme a match, quick! (4, Funny)

Impy the Impiuos Imp (442658) | about a year and a half ago | (#42689761)

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 ... (4, Funny)

Ihlosi (895663) | about a year and a half ago | (#42689827)

... to sodium. Instant, on-demand hydrogen!

Re:Why "silicon nanoparticles"? Just add water ... (1)

140Mandak262Jamuna (970587) | about a year and a half ago | (#42690385)

Silicon is orders of magnitude more abundant than sodium. Half the mass of earth is silicon dioxide. But sodium is abundant enough too, about 1% of the mass of the sea water is NaCl. Electolysing sodium from saline solutions might be easier. And we might not even need sodium to be a nano particle to react with water. Dont know why anyone would mod this funny, though.

Re:Why "silicon nanoparticles"? Just add water ... (1)

RaceProUK (1137575) | about a year and a half ago | (#42690861)

Depends on the reaction speed. Sodium reacts quick enough to (sometimes) generate enough heat to light the hydrogen immediately. The silicon version, if it has a slower reaction rate, will produce less heat, so the chances of premature ignition are significantly reduced.

10nm particles... (5, Insightful)

BLKMGK (34057) | about a year and a half ago | (#42689871)

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?

Re:10nm particles... (0)

TheSkepticalOptimist (898384) | about a year and a half ago | (#42690143)

Now if only there was some kind of profession that would have people investigate and research all these questions.

Re:10nm particles... (1)

gestalt_n_pepper (991155) | about a year and a half ago | (#42690549)

Um, I think that's us. You know, the crowd. With wisdom and all that.

Re:10nm particles... (-1)

Anonymous Coward | about a year and a half ago | (#42690193)

I have an idea, why don't we all just give up, commit suicide, and leave the world to the lesser creatures? You go first.

Re:10nm particles... (1)

VortexCortex (1117377) | about a year and a half ago | (#42690217)

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.

Re:10nm particles... (0)

Anonymous Coward | about a year and a half ago | (#42690373)

What happens when it hits the water IN a human?

Live comfortably for up to* 30 years, then cough and fall over dead.

*past outliers are not a promise of future survival rates

Re:10nm particles... (1)

mdielmann (514750) | about a year and a half ago | (#42690943)

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?

Virtually every question is answered in the summary! We have a new low, people!

Health impact: nano particles are up in the air (small particles tend to be more dangerous for biologicals than large particles of whatever they are made of), hydrogen is turned into water, silicic acid is non-toxic. Purity of water isn't mentioned, nor what happens if it is exposed to other stuff, but you can assume it will react with something if you ingest it.

Reaction components: Si + H2O -> Silicic acid + H2. It can't be releasing (much) oxygen, or the fuel cell would look like a nice little camp fire in short order. This is also why it's not equivalent to using sodium or lithium. Feel free to use google and see the chemical composition of silicic acid. Again, silicic acid is claimed to be non-toxic, so that's not a big deal. How it reacts with other stuff isn't mentioned, but you can assume it will react with a number of things if it will react with water, so they will probably assume you use relatively pure water. Blood probably won't work to well (or cleanly), something from a ditch probably will. Since one of the byproducts is silicic acid, it's safe to assume the particles will be consumed in the reaction.

As for water being used in production, we're talking about silicon, here. We already process this stuff for making computer chips, so you can check out how much water is used for everything but the last step by examining that process.

There's the answer to over half your questions, based on reading the summary and high school chemistry. I imagine even more would be covered in the article. Google can probably answer half of what's left over after that.

Re:10nm particles... (1)

kevkingofthesea (2668309) | about a year and a half ago | (#42691213)

The oxygen (and probably one of the two hydrogens, as well) is captured as part of the above-mentioned silicic acid. It is probably recoverable to some degree, although it may be impractical - hard to say without more detail.

Impure water would probably work, but you may produce some undesirable by-products (perhaps even through reactions with the silicic acid produced by the primary reaction).

Of course this is all educated speculation on my part, but those are good questions to be asking.

Still no free lunch (2)

jamesl (106902) | about a year and a half ago | (#42689889)

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.

Sicilian Bonaparticles? (1)

jkg2 (2751749) | about a year and a half ago | (#42689989)

what?

There's No Mention of the Catalyst? (1)

LifesABeach (234436) | about a year and a half ago | (#42690113)

The overall reaction produces hydrogen and silicic acid by-products; this looks promising. What Catalyst(s) would be required to convert the Other byproducts back to a useful configuration, and convert the silicic acid back to the spherical silicon nanoparticles when the water runs out?

Re:There's No Mention of the Catalyst? (1)

bluefoxlucid (723572) | about a year and a half ago | (#42690165)

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 reactionary products of the fuel would absorb heat, see above.

Could be combined with... (0)

Anonymous Coward | about a year and a half ago | (#42690125)

...this, just announced from the University of Michigan [umich.edu] to make silicon crystals at much lower energy than previously required.

The crystalline silicon in modern electronics is currently made through a series of energy-intensive chemical reactions with temperatures in excess of 2,000 degrees Fahrenheit that produces a lot of carbon dioxide," said Stephen Maldonado, professor of chemistry and applied physics.

Recently, Maldonado and chemistry graduate students Junsi Gu and Eli Fahrenkrug discovered a way to make silicon crystals directly at just 180 F

Seemingly good by-product (1)

TheSkepticalOptimist (898384) | about a year and a half ago | (#42690137)

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 (3, Funny)

pr0nbot (313417) | about a year and a half ago | (#42690187)

How long have we got till peak silicon? I'm going to start stockpiling sand for the forthcoming commodities bubble.

Re:Great (3, Funny)

Specter (11099) | about a year and a half ago | (#42690391)

Just try to keep your cat out of it, alright?

On the other hand (0)

Anonymous Coward | about a year and a half ago | (#42690243)

I'd rather run out of hydrogen than water; sweet, cool water.

It's still about net energy (2)

gestalt_n_pepper (991155) | about a year and a half ago | (#42690519)

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. (1)

udoschuermann (158146) | about a year and a half ago | (#42690587)

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?

Re:Film at 11. (1)

gmuslera (3436) | about a year and a half ago | (#42691021)

Is not a catalyst, it is consumed by the reaction, so no matter if the amount to convert a glass of water is dropped in the ocean, will produce the same amount of hydrogen and acid.

Bad trade (1)

gurps_npc (621217) | about a year and a half ago | (#42690797)

So instead of storing compressible lightweight hydrogen, they want to store incompressible, far heavier water?

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.

Re:Bad trade (2)

higuita (129722) | about a year and a half ago | (#42691245)

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 just need some "bucket" or simple container and that's it, no safety problems (other of people trying to drink it maybe!).
Rust is only a problem with some materials and have currently many easy solutions (other material, coatings, alloys). Unless you are using sea water, its not different from your water supply at home. Even it there is a leak, there is usually no big problem.

H2 bad for O3 (0)

Anonymous Coward | about a year and a half ago | (#42690843)

Hydrogen is not the panacea of clean energy. Unless you can burn 100% of it, your H2 material is going to rise in the atmosphere and leave the earth eventually but not before passing through the ozone layer where it is more than happy to combine with that extra O in O3 and make water, destroying the Ozone layer in the process.

ICE NINE (0)

Anonymous Coward | about a year and a half ago | (#42691003)

Just sayin'.

oxygen (1)

More Trouble (211162) | about a year and a half ago | (#42691471)

If only we had an easy way to make an oxygen free environment to store our silicon nanoparticles prior to wetting them...

Load More Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Create a Slashdot Account

Loading...