Hydrogen Generator

[fungus]

I've just made a small prototype of my hydrogen generator. It's very simple, I fill a bottle with caustic soda(sodium hydroxide) and put strips of aluminium cans in. It bubbles a lot and I put a cap on top with a tube. So far I have filled 7 bottles with hydrogen from two cans which i put a cover over and it's still going. My use would probably be for heating although I might experiment with fuel cells. I'm wanting to upsize it and maybe put some electrodes in for generation from solar panels. Would this work, having both the aluminium and the electrodes in the same container, as long as they werent operating at the same time? Also what sort of container could be used? I'd like to have one that i could pop entire cans into at once and screw the lid on. I can easily get some nearly empty small propane tanks to use as tanks as well. One more question, should I go pressurized or not?

[iFred]

This may be more dangerous, not sure of your ability. Don't blow yourself up and don't mix hydrogen and oxygen together, lest you end up with no balls!

Hint: this web site is large, look carfully for the links (the web site is badly written) , look at the electrolyizer projects! spent a week or so inside.

http://oupower.com/index.php

[Bruce S]

First things that come to mind are YIKES!!!

After getting over that, here's some things you need to know.

When filling even these bottles, you need a way to force out any normal air and any O2 by-products. These will cause what could be dealy results.

Have you taken heat measurements of the chemical reactions yet? as they continue things are goona get hot!

Depending on your needs , still just experimenting then no you shouldn't need to pressurize , but if you plan on extended use then you'll need to look into ways to "dry" the H2 before sending it to a pressurized tank for storage.

Greatest of care on this one. Hydrogen is indeed easy to make, much much harder to store and so far no tank built will hold it perfectly due to its molecular size.

Take a browse over the homepower website and read what they did, it'll help tons.

Bruce S

 

[dinges]

You probably mean

Famous last words: "I've just made a small prototype of my hydrogen generator. It's very simple."

[dinges]

You want to heat with it?

I haven't made the calculations, I'll leave that to the reader, but you'll probably find that it takes much more energy to make the aluminium from bauxite (and make the NaOH) than you will ever recover as energy. So, from an overall energy-balance point of view this doesn't sound like a good idea. It takes a LOT of energy to produce aluminium.

[Tallwind82]

Hi Fungus

I tend to agree with Dinges. The total costs just aren't worth what little heat you will get out of it.

I do believe that it is worth while to pursue hydrogen as a way to store energy, however I think that manufacturing hydrogen from something that you can't get free, or nearly free, is not going to be cost effective.

If you want to have a practical hydrogen / alternative energy setup, I think your best bet is to use wind, solar, or hydro power to generate hydrogen from water. The biggest concern is how to store the hydrogen until it is needed, whether for a fuel cell, or to burn for heat. A hydrogen tank is like a huge battery that doesn't wear out.

Personally I hope to someday build or buy a fuel cell and use it to power my car. I can generate more than enough power from the creek that runs through my property to create hydrogen for the fuel cell. The problem is, fuel cells are expensive $$$

If anybody out there hasn't tried getting hydrogen from water, try this: fill a bowl with water and mix in some salt. Fill a bottle with the salt water and place upside down in the bowl(make sure no air gets into the bottle). Attach a wire to each terminal of a battery (C or D cells work good)and place the other end of the + wire into the mouth of the bottle, and the - wire in the bowl. You should immediately see bubbles of hydrogen start filling the bottle. The oxygen will combine with the copper from the wire creating copper-oxide.

It's been a while since I tried it so I might have the polarity reversed.

Have fun, and don't forget, hydrogen gas mixed with oxygen is always dangerous!!!

[Geo K]

Stretch a balloon over the pop bottle, fill it with hydrogen and let it float around the kitchen

All day. Then next morning when it shrinks to the size of a small grapefruit put on safety

Glasses and ear plugs and touch a lit match to it. I bet after that you will quit experimenting with Hydrogen. It might help to open the kitchen windows first so you won't halve to pick broken glass off the lawn.

Bin there done that.

GeoK

[Chagrin]

Maybe even rub the balloon on your head a few times until you induce static electricity. It's a mind-opening experience.

Seriously, be aware of the fact that Hydrogen/Oxygen mixes are quite dangerous.

[pyrocasto]

Though I agree hydrogen is quite dangerous, that's a little exaggerated. I've seen balloons the size of basket balls lit indoors. Yes it's loud but it wouldnt bust your windows out(depends on situation I guess), especially a grapfruit size.

Remeber, though hydrogen is dangerous it can be as safe as propane if handled correctly. ;-)

[fungus]

Thanks all,

Yes I am aware of the dangers and I'm being carefull. I put some tissue paper in the cap to act as a filter to catch any caustic soda that's brung up as well. I've tried electrolysers before with similar proportions and I know what i'm doing. I was doing the experiment because I get through a lot of cans(I've got 19 in my room(15 making up a solar heater))and I thought it might be a good idea to use them in a different way than just popping them in the recycling bank. Still, could I have electrodes in the same container?

[fungus]

Also, I've tried exploding a few bottles and it's not that bad, sometimes it makes a bang and scorches the wires of the igniter but sometimes it makes a hum like when blowing on the top of a bottle and a lot of heat comes out.

[fungus]

By the way, be careful with the salt since it also makes poisonous chlorine gas.

Could I somehow flush the bottles with some sort of gas?(sorry for lots of posts)

[BigBreaker]

If you want heat - never make electricity first.  Use a solar water heater and circulate the hot water under your floor.  Alternatively invest in a ground source heat pump and run it with a turbine or direct couple.

There is currently NO way to store H2 well.  Metal Hydrates are only OK and mostly beyond a tinkerers tech level.  Better to convert H2 into ammonia, methanol or methane.  You need a carbon source for the last two though... good luck there.

See step one - don't play with H2 for heat unless you are really just playing.

[Bruce S]

Actually, though metal hydrides can be tough to work with they are well within the scope for most people on this forum.

Homepower did a real nice write up a few years back on just how to do this and it's still a viab;e route.

I agree though, as a heat source it's not the way to go. Making H2 froma dump load is another more usefull route.

 The low voltage needed to break to bonds can be a good way to go for those time when the winds are up, the batts fully charged and the sun is peaking.

IMHO: Would be a good use then

Cheers!

Bruce S

 

[nanotech]

Or when the mill isn't QUITE producing enough voltage to start charging the bank.  Electrolysis can operate at any voltage.....  

[electrondady1]

i find the low voltage required for electroesis interesting. as nando has mentioned , a cell could be set up to make us of the current when it is less than charging voltage.

[richhagen]

Absolutely.  This is not a useful way to generate heat and power on a large scale.  I recall about 20 years ago, making hydrogen filled garbage bags with foil and lye to generate the hydrogen.  Also made a torch by burning the gas as it exited a tube from the reaction chamber (don't try that as one time it got lit too soon, and stuck a glass tube through the ceiling as a result - what engineering students did back then for fun on a Saturday night)  It is a caustic mix and gets very hot.  If the hot lye gets on your skin you will be burned very quickly as the reaction rate generally increases with temperature, and the lye desolving the fat in your skin cells is not one of the exceptions.  In your eyes, I don't even want to think about that one.  

As a fuel source, I would think you would want to dissociate water into hydrogen and oxygen.  Electrolysis is not that efficient, but on a small scale at home, I do not know of a better way off hand.  Basically, you would be trading a larger amount of electrical energy for a smaller amount of energy stored chemically as hydrogen.  I have generated hydrogen on a small scale by electrolysis by placing an inverted container in the solution which captures the hydrogen as it is generated and bubbles up from its electrode.  I just let the oxygen bubble to the surface from its electrode.  I assume you could use a gas capture method similar to a methane digester to capture and use the gas in a larger set up running.  There are some articles about that type of setup in issues of the Electronic Self Sufficiency Newsletter by the late Burt Rutan from last year sometime.  It would have to be a little different, using the depth of the tube capturing the hydrogen and the resultant water pressure to maintain the pressure.  It could be used in parallel with a dump load for surplus power once the batteries are charged, but again I do not think that the efficiency would be very good. One would have to bleed the system of air before igniting anything.  

It would be interesting to see if one could make a small scale system to run a small cooking stove or such that was modified to run on hydrogen.

Anyway, just a couple of unfinished ideas, Rich

[willib]

i made this  to extract hydrogen and oxygen from water .

all the zink plates are connected together and all the copper plates are connected together, it actually came from another experiment , but worked well as an electrolyzer

it has very low resistance in water because the plates are so close together, and they are electrically isolated

[fungus]

I'm starting on something like that ,willib, with transformer laminates with tiny spacers put in.

[willib]

just be carefull, it really produced some H2 & O2, almost immediatly

the H2 & O2  is impossible to seperate , so , what you end up with is an explosion waiting to happen , i cant stress enough to be carefull !!

[willib]

Dan could you please remove my first post in this topic , thanks

[electrondady1]

too late now willib , if fungus blows the house up it's all your fault. lol
i wonder if hydrogen could be captured as the byproduct of a plating operation?

[Tallwind82]

BOOOOOM

[Tallwind82]

I hadn't thought about the potential for separating the chlorine from salt (potassium chloride), I wonder how much is actually released. I always assumed that all the remaining salt would merely recrystalize once the water reached the point of saturation.