While conducting some research into using hydrogen peroxide to dechlorinate tap water, something dawned on me: the result of the reaction is oxygen. Of course, this led me to wonder how this might be applied in other ways. Perhaps there was a cheap and easy way to generate copious amounts of oxygen for other uses and research. Time to go play with household chemicals (please don't do this kind of thing unless you understand the chemistry and know what you are doing)!
![oxygensoda.jpg [20.69k]](images/oxygensoda.jpg "oxygensoda.jpg")
I decided to see how much
oxygen could be generated, and what the reaction would look
like, when mixing household bleach and hydrogen peroxide. For
those of you familiar with stoichiometry, it's a relatively
simple reaction (NaClO + H2O2 → NaCl
+ H2O + O2). If you're not good at
chemistry, that equation means that when you mix household
bleach and hydrogen peroxide you're left with some saltwater
and oxygen bubbles and nothing else. The formula weights tell
us that we need about 25 mL of 3% peroxide solution to react
with 30 mL of household bleach.
Of course, I'm not a total idiot, so I made a dilute solution of bleach and slowly added it to a weak solution of peroxide — mixing the two undiluted might cause a very quick reaction that throws bleach and peroxide all over the place. The result was club soda sans CO2. This is very cool. Very small amounts of bleach were producing what appeared to be large quantities of oxygen. Doing some quick estimating, it seems like we can generate about 28.2 grams (about 16 liters) of oxygen for about $3 — the cost of a bottle of bleach and a bottle of peroxide. Of course, it's probably easier just to go get a tank of oxygen, but definitely not as cool. Plus, in an emergency, you can take advantage of household chemicals to get oxygen into your tank fast. Just mixing about 200 mL of peroxide and 240 mL of bleach would generate enough oxygen to fully saturate a 125-gallon aquarium that had zero oxygen (assuming 100% efficient injection). I'm thinking it would probably be easiest to feed the oxygen directly into your CO2 reactor. Oxygen does not displace CO2, so it shouldn't affect the CO2 much.
I am still mulling over the cost/benefits of building a simple oxygen injection device using this principle versus just having a small oxygen tank around. You can buy little tanks at most hardware stores for small welding kits. It would be helpful in quickly saturating a tank with oxygen in an emergency. Stay tuned.
