Sciencemadness Discussion Board

Hydrogen Peroxide and Carbonic Acid Reaction

Hydrazine - 6-9-2017 at 12:35

Hello All,

I have a project where I would like to use 35% Hydrogen Peroxide as a low grade oxidizer propellant. (It barely works but it works.)

I would like to use CO2 as a pressurizing gas in the Peroxide propellant tank, but, as we all know CO2 is very soluble in water and forms Carbonic Acid.

Will there be a reaction between the CO2 or Carbonic Acid and the Hydrogen Peroxide?

Percarbonic Acid?

I dont know but I sure would like to find out before trying it.

zed - 6-9-2017 at 16:17

Baking soda.

Hydrazine - 6-9-2017 at 16:56

No sodium or bases will be involved.

j_sum1 - 6-9-2017 at 17:43

Well, thinking this through logically.
H2O2 is an oxidiser. As CO2 the carbon is already fully oxidised. So therefore no reaction.

Looking at it another way, piranha solution is a way of oxidising persistent carbon-based substances. The products of the reaction includes CO2 which leaves the vessel unaffected by the peroxide. Therefore, CO2 is the end of the line as far as reaction with peroxide goes.

Hydrazine - 8-9-2017 at 11:36

I'm not so sure about that.
CO2 will react with water, endothermically, to form Carbonic acid. IE Carbonated water. Soda water.
I believe this is oxidation of the CO2.

Elemental Phosphorus - 8-9-2017 at 14:16

Quote: Originally posted by Hydrazine  
I'm not so sure about that.
CO2 will react with water, endothermically, to form Carbonic acid. IE Carbonated water. Soda water.
I believe this is oxidation of the CO2.

The reaction of water and carbon dioxide is neither oxidation nor reduction. It is the hydration of an acid anhydride. Carbon dioxide is the anhydride of carbonic acid.

AJKOER - 9-9-2017 at 09:41

Per a source (see, for example, "The Mechanism of Carbon Dioxide Catalysis in the Hydrogen Peroxide N-Oxidation of Amines", Inorganic Chemistry (ACS Publications), link: ), to quote:

"The reactivity of the peroxymonocarbonate ion, HCO4- (an active oxidant derived from the equilibrium reaction of hydrogen peroxide and bicarbonate), ..."

The cited equilibrium reaction is given by:

HCO3- + H2O2 = HCO4- + H2O

with the creation of peroxymonocarbonate ion.

I have noted the presence of this ion by the following experimemt: Add the same amount of NaOCl to H2O2 and then to a NaHCO3/H2O2 mix.

With respect to the recorded volumes of oxygen, one apparent observes a reduction in the volume of formed O2 in latter case. Expected reaction, ignoring the formation of the peroxymonocarbonate ion, in each case would be given by:

NaOCl (aq) + H2O2 = NaCl + H2O + O2 (g)

As such, using CO2 with H2O2 may produce a change (decline, I would guess) in rocket propulsion, which may even vary with fuel employed. Adding copper ions to the fuel may improve results due to increased radical formation during combustion (but test on a small scale).

[Edited on 9-9-2017 by AJKOER]

Hydrazine - 12-9-2017 at 16:17

Interesting. While I considered a carbonic piranha reaction, I dismissed it because I thought the anhydride was too weak and needed to be a powerful acid. Like a mineral acid typically used in a piranha formula.

Thanks for the lead. It shows at least somebody has previously reacted it and it didn't end in a catastrophic surprise.

I'll start with small amounts in high ullage tanks and test it's stability, reactivity and decomposition characteristics.
Gotta be real careful with peroxide in pressure vessels. Even at 35%.
Add in a piranha element and it might get hairy.

Hydrazine - 13-9-2017 at 12:05

And yes, I will salt it with a dash of copper salt in the fuel.
I planned on using iron salts to make a fenton reaction but yes, copper is worth trying too. If nothing else, it will make a beautiful blue green exhaust plume.