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Sewage To Be Turned Into H
Anonymous Howard writes "The New Scientist website reports in this article that British scientists are working on a more efficient way to convert sewage and other wet waste into hydrogen fuel. It sounds fairly promising."
Get it straight: Sewage is to be turned into H2, not H. Elemental hydrogen is unstable and is not used as a fuel. Hydrogen gas (the molecule H2), on the other hand, can be burned to form energy.
Hydrogen is abundant. However, it's also very reactive and forms compounts rather easily. So we have lots of hydrogen, just not in the form of H2 which is the form that is wanted for fuel.
Okay... a few thingns...
3 18 / uantumcorp.html
what does 20% efficient mean? There's this lovely quote that it's twice as efficient as our current 20% efficient systems... does this mean you get 20% more out of it than what you put in? If so, it's not bad considering we have more than enough raw sewage to process. However, we have this other problem. What do you do with hydrogen? Sure, you might be able to make some sort of power plant to process the stuff. In fact... some researcher have done it... check this out...
http://www.geocities.com/ResearchTriangle/Lab/9
93% efficiency... not bad. But hydrogen is dangerous stuff. I'd say a large amount of hydrogen is more dangerous than a large amount of reactor-grade uranium... considering all it takes to make hydrogen explode is air and heat. That's one of the reason we don't have hydrogen-powered cars. I don't know anybody else... but if they're looking a something like this, they'd better find a safer way to store hydrogen first. Maybe make a big tank out of a bucky ball and put the hydrogen in there...
The Internet, one place where if you're not right, someone else will set you straight... maybe.
What does that say about our geek-ness, or lack of it, when we see "H" and think heroin instead of hydrogen?
It means we know the difference between H, H+, and H2. Hydrogen, like oxygen, nitrogen, and the halogens, is diatomic, meaning that it exists in nature in pairs (Cl2 I2 F2 Br2 O2 H2 N2). In nature, it also exists as positive ions (labeled H+); Bronsted acids give off these. (Water is amphiprotic; that is, it's a weak acid and base simultaneously.)
When I see "H2", I think "hydrogen." When I see "H+", I think "hydrogen ion" and then "there's an acid somewhere around here". Plain "H" by itself is heroin, just like "X" without the "Window System".
Will I retire or break 10K?
http://spacedaily.com/news/energy-tech-02j.html
Tells you a bit more about the process and the diagram gives you a good glimpse at the device.
--foolish
You can make hydrogen at home. It's sort of safe.
Ingredients:
Granular Lye
Aluminum foil
water
PLASTIC gas can
garden hose
1.Take the little gas spigot, and attach to garden hose with duct tape or somthing. Attach the other end of the garden hose onto a garbage bag.
2. Now, take about 1 sq. foot of foil. Make a thickish line of lye on the aluminum foil. Roll it up until it looks like a cigar.
3. Fill the can with 3/4 inch of water.
4. Now, as quickly as you can, cap the gas can. Much of the hydrogen is produced in the first few seconds.
5. Sit back and watch your bag fill up with hydrogen. The gas can will get very, very hot during the reaction. The reason for the hose is so the water vapor can condense.
Now, you can do all sorts of things with your hydrogen:
1. Blow it up. When you make hydrogen for exploding, include about 50% air in the bag, to provide enough oxygen for rapid combustion. This is not very dangerous. The hydrogen blows up too fast to burn you. The worst exploding hydrogen can do is singe your eyelashes. The main danger of this is getting hit by the burning plastic bag. Blowing it up is very fun. It even makes a shock wave. However, I suggest igniting it with a 10 foot long pipe with a match on the end.
2. Make a balloon. Just get the hydrogen as pure as can be. Then, tie up your bag when it is full. On a still day, just realease your balloon. Attach some colorful paper or somthing to it so you can see it on it's ascent. If you only fill the bag a third of the way full, your balloon should reach about 40,000 feet.
3. Breath it. It creates a high-pitched voice just like helium. Hydrogen is completely non-toxic. Just don't go near flames for a few minutes! (-: Also, don't stick your head in the head in the bag or anything. You could suffocate. Hydrogen is non-toxic, but without oxygen, you would die. You also wouldn't realize you needed to take a breath. When you hold your breath, the burning in your lungs is C02. Since you are inhaling pure hydrogen, which is not metabolized into CO2, you would have no idea that you needed to take a breath.
If you don't understand any of my sayings, come to me in private and I shall take you in my German mouth.
BTW, might I add that the byproduct of the lye-foil reaction is more corrosive than battery acid? It will burn you if you come into contact with it.
Also, you can put multiple fuel cigars into the gas can.
If you don't understand any of my sayings, come to me in private and I shall take you in my German mouth.
Brevity is the soul of wit, which makes me a clod. Sorry. I've actually got a degree in this, so here it goes:
H2 + O2 -> water + energy
everyone knows this, right? You burn hydrogen, it makes heat. So, conversely,
water + energy -> H2 + O2
this is splitting water; you can do this at home (not that I recommend this!) by taking the two leads from a power supply and dumping them at opposite ends of a glass of water. The bubbles you see (just before the explosion) are hydrogen and oxygen gas.
Now, when you run a reaction that goes
stuff -> other stuff + energy
the reaction makes the environment warm. Like a piece of wood burning.
Likewise, when you run a reaction that goes
stuff + energy -> other stuff
it makes the environment COLD. A simple home experiment you can do (in perfect safety) is to take a glass of water and then upend a container of salt into it. The glass of water will get cold, because:
NaCl (salt) + energy -> Na+ + Cl-
Now, the question is - why does Salt dissolve? The answer is: entropy. Entropy is one of the most difficult of all concepts to explain (especially when it results in organised phenomenon, such as life) but, basically, Entropy is the tendency of bigger aggragates (NaCl) to shatter into little pieces (Na+ and Cl-). There is a quantifiable relationship between the amount of entropy a reaction produces (the log of the number of pieces around) and the amount of heat (energy, in joules or calories) that a reaction must "liberate" into the environment in order to go (i.e. be "spontaneous"). A reaction that breaks things apart AND releases heat into the environment - like wood burning - will always go. A reaction that takes heat from the environment, and builds things up - such as a tree forming from water and air, bear with me - will never go; living things exist by coupling spontaneous reactions to non-spontaneous ones, the net reaction can be spontaneous even if one half of it would not be on it's own:
water + air + energy -> tree (non spontaneous)
concentrated heat (from sunlight, incidentally) -> dissipated heat (spontaneous)
water + air + concentrated heat -> tree + less dissipated heat (spontaneous!)
See? We're allowed to continue existing.
So, for any given reaction, you COUNT the amount of entropy the reaction makes, and if that is BIGGER than the amount of heat the reaction takes up (as is the case when salt dissolves) the reaction goes.
Okay, now, if there isn't any hydrogen around (because all of it has filtered away) the amount of entropy you produce by liberating X hydrogen (it's a log, recall) is much, much greater than if there is already a lot of hydrogen around.
So, to go back into the kitchen, if there is already a lot of salt dissolved in the water, the reaction
NaCl + heat -> Na+ + Cl-
produces less entropy. Eventually, the entropy produced by the NaCl dissolving no longer outweights the heat required to break it into two pieces, and the salt stops dissolving. You can empty a second canister full of salt into your glass of water, and it will all filter to the bottom, the water will get no saltier.
A similar thing happens with heat. If you take your salt-water with salt on the bottom and put it onto the stove, more salt will dissolve - ignore this if it doesn't make sense: this is because the more heat there is the environment, the less entropy (disorder) the environment loses when it puts any given amount of heat into the system.
The famous mathematical expression of all this is:
Total Entropy Change = Heat "Liberated" / Temperature + Log (change in amount of stuff)
(this is more commonly said dG = dH - TdS)
When I say Heat "Liberated", I mean heat which comes from the "system" (your glass of water) into the environment. If the glass of water makes the environment cold, this value is negative. 80% of PhDs can't keep the signs straight, so don't worry if something seems backwards. You're not alone.
So, doubling the amount of something always produces the same amount of entropy. If you have 60g of hydrogen, you need to make 60g more to produce (60,120) 1 "unit" of entropy. However, if you've got only 4g of hydrogen around to start with, making 60g more produces (4,8,16,32,64) 4 "units" of entropy.
So, in the reaction-
CH4 + H2O + heat -> 3 H2 + CO2
Here we are breaking things into pieces (4 pieces on right, 2 pieces on left), so the reaction is driven forward by entropy. There are two things you can do to drive the reaction forward faster.
1) You can add more heat; if you add more heat, you will make more hydrogen.
2) At any given temperature, you can drive the reaction forward by taking hydrogen away - this is what they're doing in the article. As the reaction goes forward, the hydrogen bubbles off.
Another kitchen chemistry experiment. Put two pots of water on the stove, full of water. Cover one of them. The one that you don't cover will boil away and turn completely into steam, right? This is because there is no steam in the air immediately above the pot, so when a particular water molecule becomes steam, the entropy gain is huge. The covered pot, on the other hand, will not boil away entirely (of course, eventually it will but in the short term I mean,) instead, it will boil away until a certain concentration of steam is reached in the air in the pot, and then stop.
So, if you want to boil water away more efficiently, you set up a system to blow the steam out the window (or collect it somewhere that you want to keep it) so that the air in the kitchen doesn't get humid. That's what this group has done.
Congratulations, you now know thermodynamics. That's really it.
They've also added a catalyst that makes the reaction go faster, but I'll save my explanation of kinetics (the study of how FAST reactions "go", as opposed to weather or not they go at all) for another time.
Since you've read this far, you get to know the collective secret of the scientific community: we are so high right now. Snoop Dog ain't got nuthin' on us; reefer in hand 24/7. Do you think I could've written this long schpeal without beaking baked off my derear? Oh, man, have I got the munchies.
The good and new comes from no quarter where it is looked for, and is always something different from what is expected.
Dumping it down your household drain would be a better solution. Drano & the like are Lye, so I wouldn't expect that this would be any worse. It'll just get removed at the sewage treatment plant. Dumping it on the ground could effect the environment more directly, though I doubt it'd be too much of a problem. I would probably not dump it down a storm drain, however, as they frequenty drain directly to rivers or lakes. Of course, I am only guessing about all of this, so someone please correct me if I am wrong.
Um, that doesn't happen.
Sure it does. Ever hear how the electric chair was invented? Tesla's invention of the A/C motor finally made widespread distribution of electricity feasable. The problem was that Edison only had patents on D/C generators. The public had to be convinced that D/C was better. Conveniently, New York State was looking for a new, "more humane" way to execute prisoners. Edison proposed using A/C power to electrecute them, thereby demonstrating how dangerous A/C was. Unfortunately, his plan backfired when the first victim was still alive (albeit smoking) after four full minutes of current. See the book Blood & Volts by Thomas Metzger for more history.
Fuel cells are closed systems, and the expensive part is recharging a cell and not filling it in the first place.
I don't understand. The hydrogen is the fuel in the fuel cell. You don't recharge a fuel cell, it works like an engine (though using the movement of electrons and protons instead of mechanical parts). And it's not a closed system. You put fuel in, and electricity and waste (water) comes out. Nothing stays internally. Read more about how they work here.
Besides, hydrogen has so many other drawbacks due to its low molecular weight, that the main problem isn't getting hydrogen it is using it.
There are two drawbacks. The first is you need to compress it to get a good power/volume ratio, and the second is that the molecules are so small they tend to leak out of anything trying to contain it. They are simple engineering problems though. The former we can already do without problem. The latter various materials are being tested for containers, as is storing the hydrogen within another compound such as boron and then using a catalyst to release it upon demand.
Phillip.
http://www.FutureEnergies.com/
Property for sale in Nice, France