Unconventional co2 setup

[ChicoRaton]

I found this article today, http://nucalf.physics.fsu.edu/pfohl/Fish/Diy/co2 , and the setup looked interesting. To save you from reading the whole thing, I'll paraphrase.

an HCl solution (muriatic acid) drips into a chamber containing sodium bicarbonate (baking soda) and releases co2. The guy estimated the cost of co2 with this method at $1.60/lb, and a lot more stable than yeast. I have a few ideas for modification, which I'll draw up and post soon.

Has anybody else tried this? It would take some experimenting and stoichiometry to get the exact acid-baking soda ratio down, but would be efficient once you did figure it out.

Anyway, I'll get to work on my modifications and post an image asap.

 

[ChicoRaton]

The tube connecting the acid and baking soda chambers is to equalize the pressures. the acid is gravity-fed into the baking soda chamber. This eliminates tha balloon, a big point of failure. It will also cause the acid flow to slow down slightly as it empties, though. Anybody have an idea to counteract this? anyway, once you figure out # of bubbles of co2 per drop of acid, you set it to drip the correct rate, maybe 1 drip every 30 seconds, and you're set. This is a very young idea, so any ideas for improvement would be greatly appreciated.

 

[anonapersona]

Maintaining pressure?

Muratic acid is really nasty stuff, I wouldn't have it anywhere inside my home, particularly open the atmosphere where it could spill. I had a bottle of it in the garage, wrapped in a sealed plastic bag on a metal shelf. In the summer heat, the vapors wept though the bottle and the plastic and destroyed the metal shelf it was all settiing on.

Vile, horrible vapors, nasty stuff! Have you ever poured it straight onto concrete and watched it destroy the concrete? No, you do not want that in an open container anywhere.


You could try it with vinegar, even pickling strength vinegar, 20% vs normal 5%. But I think the dillution in the reaction jar would make the production very unstable.

 

[Torf]

Where is all that Hydrogen and Chlorine going? It would probably be best to have a good idea of the reaction before hooking this stuff up to your pets.

Glass containers should handle hydrochloric acid even at it's strongest concentrations, but the tubes valves and connections probably wont.

 

[ChicoRaton]

Where is all that Hydrogen and Chlorine going? It would probably be best to have a good idea of the reaction before hooking this stuff up to your pets.

here's the reaction:

HCL+NaHCO3-->CO2+NaCl+H2O
or
" " " " " "-->CO2+NaCl(aq)
As you can see, the hydrogen and chlorine are just going into water and sodium chloride.

Glass containers should handle hydrochloric acid even at it's strongest concentrations, but the tubes valves and connections probably wont.

it might be worth noting that muriatic acid is sold in plastic bottles. I'm not sure of the type of plastic, I think it's pvc. Many other substances are non-reactive with HCl.

Muratic acid is really nasty stuff, I wouldn't have it anywhere inside my home, particularly open the atmosphere where it could spill.

Muriatic acid is pretty concentrated. I believe it's either 20% or 30% HCl by weight. If you think muriatic acid is bad, you should see what happens to things that get concentrated hydrochloric acid on them

And as you can see from looking at the diagram, once charged, this system is completely self contained for as long as your reaction products last, then, if you did the stoichiometry right, you'll be left with salty water as a waste product.

This guy was using a setup like this to run a calcium reactor on his marine tank for some time, so it is a proven design, I just feel it would work better without the balloon. It would probably be good to mount the whole setup on a modular type rack too so you could disconnect it to charge it fairly easily.

 

[TonyN]

Well, I agree with the other posts. That's really some nasty stuff to have in the house. If that setup ever blew, you might as well start looking for a new place to live. (Oh yeah, and hope like heck you're not home if it does go.)
Do yourself a favor and forget about it.

 

[Mako]

by the time you build all that junk you can buy a 20-lb can of CO2 from a welder's supply place, a used regulator from Ebay or Aquabid, and a homemade reactor from an upside-down gravel cleaner fed by a small powerhead. 20 lbs of CO2 cost about the same as a 10 lb can in my area, and is the same price refilled (which will take a very, very long time). Nothing beats compressed!