Compressed Hydrogen

[L.J.R]

Most of us know that when using something lighter than air in a pneumatic cannon the projectile can achieve faster velocities ie hydrogen. But how do you obtain compressed hydrogen I doubt you can buy it so I am gathering that you have to make it some way. I want to know if it is possible to make my own hydrogen gas at home and pressurise it at 100-400 psi using something like electrolysis or thermal something or wrather. spent some time searching and didn't find anything.
thanks

[FreakyShotGlass]

You can buy helium easily at party supply stores, hydrogen is not so easy to obtain. There are certain methods that will work but I reckon that helium is good enough for ligher than air cannons.

[Benny]

mmm i dont think so, 500 psi combustion pressure, very expensive, and extremely dangerous.

[FreakyShotGlass]

Benny he is talking about using it in a pneumatic.

[Benny]

I know, whats wrong with telling him the combustion pressure?

Tiniest little static spark and BOOM!

[FreakyShotGlass]

Good point, having lots of hydrogen around isn't a good idea.

[mark.f]

Where's the oxygen for the hydrogen to burn with, if he purges the chamber before filling?

[FreakyShotGlass]

If he is planning on storing the hydrogeb somewhere then it is seriously dangerous. If he purged his chamber with CO2 or another non-flamable gas then the risk of explosion would be averted. But I just can't see any advantages of using hydrogen over helium in a lighter than air pneumatic.

[Jolly Roger]

Yeah helium is only slightly denser than hydrogen anyway, too much mucking around with hydrogen.

[L.J.R]

well I thought ther might be some way to cheaply make hydrogen (yes I know it ain't the safest thing), because I don't have much money. If there is some way to make compressed helium I'd like to hear it.

[boilingleadbath]

Generating hydrogen through chemical means will cost you about .35$/mole if you use the HCl+metal meathod. Electrolosis will be a bit cheaper but more labor intensive.

A mole is roughly 3 liters volume pressurized to 100 psi.

[cannon freak]

Compressed hydrogen is safe, compressed hydrogen and oxygen is not safe.

I had a design that I haven't made yet because I can't find a suitable power supply, it was basically electrolysis machines made out of 4" PVC that could be hooked together to make a larger unit.

[zeigs spud]

wow this is my science class all over today.

The HCL (hydrocloric acid i think is how you spell it) has to be mixed with a metal that is highly reactive to it and then the gasses sperated correct? blah too much work. just get some helium or co2 acualy is safer.


quick lil question.how would a gass weighing less that air be more efficient? wouldn't a compressed gass weighing more be? Shouldn't it be better becuase more the more moving mass is A harder to stop and B has more inertia (force) to move the ammo?

[sergeantspud2]

I saw a video the other day in my science class about molecules and all the stuff and they mention electrolosis. You can use electrolosis to separate the hydrogens atom from the oxygen atom. Here is a link to the site that helped me figure elecrolosis out <a href="http://www.theodoregray.com/PeriodicTab ... rolysis</a>. I also put some thought into making a device using electrolysis to compress hydrogen and or oxygen.(I WAS NOT GOING TO USE THEM IN A CANNON)

So check out these plans and tell me if theres any flaws.

My idea is to take some clear pvc and make a U with the pipes. Then put a stick of carbon in each tube with opposite polarities. Then fill up the tube all the way to the top with water and connect the carbon sticks to an energy source. Im kinda having a hard time explaining it so heres a MSpaint picture.

<a href="http://photobucket.com/" target="_blank"><img src="http://i102.photobucket.com/albums/m111 ... olosis.png" border="0" alt="Photobucket - Video and Image Hosting"></a>
So basically after the water has turned into oxygen and hydrogen a small air pump with an input and output will be attached to compress the gas. I know this process would take a LONG time but it would be cool for a while at least. Oh yeah and That air tank will not have pure hydrogen because there is no practicall way(that I can think of) to get rid of all the air in it.

EDIT: Or instead of using a pump, I could connect the bottom of the U to a hose and push the hydrogen out. I get around 30-40 psi of water pressure so that means I could have 30-40 psi of hydrogen or vise-versa oxygen.

[cannon freak]

You know you could design a simple machine that would self pressurize, so no need for a compressor.