"spiral_72" wrote in message
oups.com...
Alright, I've got this idea. Boy, that sounds like the beginning to an
end.
I figure I can drop dry ice in a tank, cap it with a regulator and have
CO2 for some period of time for my planted aquarium. Obviously it will
require more than a handful of dry ice and chances are it ain't quite
that simple. Right now I am building a tank with a mouth wide enough to
accept an entire piece. I figger I'll pack the stuff in there like the
old shotgun wadding with a length of 2x2 or something until it's full,
and cap it.
I run a search on this over the web and the Google groups. I got the
same response: "DON'T DO IT, IT'S TOO COMPLICATED"
What's up with dat? Any particular reason? I don't want to hear that
the stuff is not sanitary either. The air in my house probly ain't
sanitary after a nice homemade bowl of chille. Heck, it's free......
They pack ice cream in it at(they sell ice crea the gas station m in
cones) and they just throw it away.
I can see what you're trying to do and I can see the fun in trying it, but
unless you're very good with a tig welder I wouldn't try that at all, I
really dont fancy my liver being spread over to large an area, it's just
fine where it is now.
If the goal of this exercise is to supply a steady stream of CO2 which can
be easily regulated / shut off, why don't you use a setup using baking soda
(NaHCO3) and a suitable acid like HCL or vinegar if you're a pussy :-)
I can't remember where I saw this but a setup with a couple of containers,
one with the acid in a ballon in a slightly presurized container, say 0.1bar
(1m water column), with a hose comming from the ballon to the next container
that contains the bakingpowder with about 2-3 cm of water on top (it wont
all disolve right away but will when the concetration goes down after time)
and another hose comming out to you tank, bubler, regulator whatever...
The theory is that when you add the acid to the saturated bakingpowder
solution the reaction releases CO2 which increases the pressure thus
preventing more acid to flow into the mixing container. When some of the CO2
is used the pressure will drop, allowing some acid to drip into the main
reactor, reacting with some baking powder thus creating some more CO2 until
the pressure reaches a equilibrium at arround the 0.1 bar mark...
The potential yield of this would be quite large, ie. pretty much governed
bu how fast you can supply the acid and how fast the CO2 gas can be used. On
the other hand you should be able to stop using any CO2 at all and the
reaction should stop itselfe because the pressure gets to high for any more
acid to flow into the main reactor and nothing more happens.
It would probably be a good idea to include a oneway valve in the hose
comming from the acid container and oanother in the hose comming from the
main reactor and a couple of stop valves would probably be called for as
well....
The chemical reaction is:
NaHCO3(aq) + HCl(aq) = CO2(g) + H20(aq) + NaCL(aq) + energy
I haven't build this one yet, but where I live baking powder is dirt cheap
and so is the HCl, one could use other acids if no HCl is available.
I would think that standard PVC drain fittings could be used, the pressure
is well within reach of standard schedule40 pipes and fittings, but one
could use schedule80 if paranoid. the hoses could be solicone of standard
vinyl hoses, as long as they're monitored close they should be fine...
What do you think, Is this approach even more insane than the Dry Ice in
container method, as far as I can see it should work just fine, just haven't
hade the time to source some materials yet...
/Morten
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