RogueRose
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H2O2 as O2 source for propane/acetylene torch?
I've come across some 35% and 50% H2O2 at an amazing price - $2.50/gal to $3.85/gal for 35/50% respectively. Unfortunately it requires either 20, 35
or 55 gal purchases. (+ $20 charge on THICK HDPE drums - not bad...). There are also 275gal totes but I didn't price those.
Last I checked tanks of O2 were pretty pricey when buying 4ft or 5ft tall tanks and the deposit on the tank was almost the price of the 20gal of 50% -
not to mention all the paperwork.
I've tried a number of catalysts for H2O2 and some are much more vigerous than others. The main ones I've tried are MnO2, CuO and activated carbon -
with the AC being the slowest catalyst which seems like it might be fairly controllable. I also see that PbO2 and Fe2O3 are viable as well as "other
metal oxides" and FeCl3
Here is an interesting article that uses FeCl3, MnO2 and potatoes to decompose H2O2
https://www.job-stiftung.de/pdf/versuche/H2O2_Decomposition....
The molar mass breaks down like this:
1 mole H2O2 = 34g
2 H2O2 -> 2H2O + O2
68g -> 36g + 32g
= 52.94% H2O
= 47.06% O2
35% = 1.13g/ml (as per Sigma-Aldrich)
1L of 35% = 650g H2O + 395.5g H2O2 (350ml x 1.13g - 395.5g)
1L 35% H2O2 = 1045.5g
1 gallon = 3958g or 8.72lbs
395.5g H2O2 (per liter) = 186g O2 per liter = 721.2g O2 / gallon of 35% (22.54 moles / gal)
20 gallons 35% = 451 moles O2 or 14,424g O2
Tanks are 125 & 150 cubic ft (there are 244 & 330 but they are a little large to handle)
Good site for gas volume/weight calculation:
https://www.aqua-calc.com/calculate/volume-to-weight
125 ft^3 = 5.06kg (158 moles)
150ft^3 = 6.07kg (190 moles)
244ft^3 = 9.87kg (309 moles)
330ft^3 = 13.3kg (417 moles)
So the 20gal H2O2 gives more than the largest 330 ft^3 tanks by about 9%. The problem is that tanks are expensive if you buy them (a full 125 is
about $250 new) and then you have rental fees of $3-9 per month for the tank depending on size. The 125ft^3 was about $36 here for a refill and the
330 about $46, so that is obviously cheaper if you own a tank or use it fast.
My issue is that I don't often need O2 but it is really nice to be able to run some with my propane or acetylene so I was thinking of setting up a
decomp chamber to feed a torch. I also have a fridge compressor that will do 600PSI and can probably use some CO2 tanks modified for O2 or find
another small tank to charge if on-demand doesn't keep up or is too dangerous.
Anyway, I just thought this might be interesting since I rarely need O2 but uses H2O2 more often (I've replaced NaOCl for many things - like laundry,
cleaning decks/houses, shocking wells and other stuff).
Has anyone tried anything like a O2 generator powered by H2O2? Electrolysis (H2 + O2) would be ideal, I have the electrical materials to make a
killer system (up to 20KW if i wanted) but the plates would be the biggest issue, especially if i wanted to separate the gases w/ membranes.. I'd
love someone to come up with a good way for this..
Attachment: H2O2_Decomposition.pdf (290kB)
This file has been downloaded 467 times
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Sulaiman
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I suspect that you should look again for bottled oxygen.
I can't imagine the long term economics of hydrogen peroxide generation vs. direct from the atmosphere etc.
You may get an occasional bargain on hydrogen peroxide,
but the complications and dangers involved may not be worth the effort ?
Check welding suppliers etc.
P.S. I just want to re-stress the danger of 35% hydrogen peroxide,
(attacked my skin faster than conc. sulphuric acid !
- don't use thumb as a test tube bung for mixing 
if some catalyst dropped in a drum, all hell could break loose ... I guess.
I certainly would not want to be nearby 
[Edited on 26-5-2019 by Sulaiman]
CAUTION : Hobby Chemist, not Professional or even Amateur
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RogueRose
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Quote: Originally posted by Sulaiman  | I suspect that you should look again for bottled oxygen.
I can't imagine the long term economics of hydrogen peroxide generation vs. direct from the atmosphere etc.
You may get an occasional bargain on hydrogen peroxide,
but the complications and dangers involved may not be worth the effort ?
Check welding suppliers etc.
P.S. I just want to re-stress the danger of 35% hydrogen peroxide,
(attacked my skin faster than conc. sulphuric acid !
- don't use thumb as a test tube bung for mixing
if some catalyst dropped in a drum, all hell could break loose ... I guess.
I certainly would not want to be nearby
[Edited on 26-5-2019 by Sulaiman] |
Yeah, I know it can be a little hazardous. A little tip if you get it on your skin, run the white spot under mildly hot water (couple mins) and press
on it with your fingernail tip. It seems to break up the white/air under the skin and often goes away in a few minutes. I've never had any lasting
burns from it if treated w/n 5-10 mins.
I think the hot water speeds up blood flow to the area as well as pressing on it, so it disperses and doesn't do permanent damage. It sure doesn't
feel good when it happens, but it is treatable if you know how. I've never seen any methods mentioned online and I came up with this on my own from
my first 2 handlings. I've never used stronger than 35%...
[Edited on 5-26-2019 by RogueRose]
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RedDwarf
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Fine control of pressure and flow from a peroxide oxygen generator would be much harder than just using a cylinder.
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RogueRose
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Yeah that's why I was thinking of using that 600psi compressor with a pre-dry system (cold then NaOH or something...)
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unionised
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Whatever it is that you are using the torch for will take enough of your attention that you won't be able to "supervise" the H2O2 rig.
That's a recipe for a disaster/
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Twospoons
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| Quote: Originally posted by RogueRose | I also have a fridge compressor that will do 600PSI and can probably use some CO2 tanks modified for O2 or find another small tank to charge if
on-demand doesn't keep up or is too dangerous.
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Using a fridge compressor for O2 is a spectacularly bad idea. There's no way you will get it clean enough for oxygen, and still functional.
I think you'd be better off investing in either electrolysis or a medical O2 concentrator. The latter are often used by glassblowers.
[Edited on 26-5-2019 by Twospoons]
Helicopter: "helico" -> spiral, "pter" -> with wings
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draculic acid69
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You'd be trying to do two things at once with this generator and torch.both require full attention so unless you have another person doing one of
those efficiently don't do it.recipe for trouble.
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Heptylene
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Yeah feeding pure oxygen into a compressor full of oil sounds like a recipe for a massive explosion. (w/ complimentary shrapnel)
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vmelkon
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I have used a refrigerator compressor to compress hydrogen into cylinders.
It was this type of cylinder:
https://www.canadiantire.ca/en/pdp/bernzomatic-propane-gas-1...
I just ran it initially without the cylinder attached so that it would fill the compressor with hydrogen.
For the oxygen, I made a special box thing that contained one of those tire compressors. Value = 20$
The electric motor caught fire. I quickly cut the power. Oxygen is a huge problem. It might even turn you compressor into a internal combustion engine
and might even blow to pieces.
Signature ==== Is this my youtube page? https://www.youtube.com/watch?v=tA5PYtul5aU
We must attach the electrodes of knowledge to the nipples of ignorance and give a few good jolts.
Yes my evolutionary friends. We are all homos here. |
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lordcookies24
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Would it be possible to use a catalyst like potassium iodide? Prob not a good idea cause you couldn't turn it off or regulate it.
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ElizabethGreene
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Would a Kipp apparatus work for accident-resistant decomposition of the peroxide?
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Sulaiman
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good idea !
one difference is that if a little calcium carbonate drops down into the hydrochloric acid solution
(e.g. Kipps generator for CO2)
there will briefly be rapid gas generation then equilibrium,
whereas if a little catalyst drops down into hydrogen peroxide solution,
there will be continuous gas production until all of the hydrogen peroxide is exhausted,
so a good screen would be required
CAUTION : Hobby Chemist, not Professional or even Amateur
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lordcookies24
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| Quote: Originally posted by Sulaiman | good idea !
one difference is that if a little calcium carbonate drops down into the hydrochloric acid solution
(e.g. Kipps generator for CO2)
there will briefly be rapid gas generation then equilibrium,
whereas if a little catalyst drops down into hydrogen peroxide solution,
there will be continuous gas production until all of the hydrogen peroxide is exhausted,
so a good screen would be required |
Is the decomposition of H2O2 autocatalyctic?
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Ubya
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| Quote: Originally posted by lordcookies24 | | Quote: Originally posted by Sulaiman | good idea !
one difference is that if a little calcium carbonate drops down into the hydrochloric acid solution
(e.g. Kipps generator for CO2)
there will briefly be rapid gas generation then equilibrium,
whereas if a little catalyst drops down into hydrogen peroxide solution,
there will be continuous gas production until all of the hydrogen peroxide is exhausted,
so a good screen would be required |
Is the decomposition of H2O2 autocatalyctic? |
autocatalytic means that one product of the reaction is a catalyst for that reaction, oxygen and water are not catalysts so no it's not autocatalytic.
a catalyst is not consumed in a reaction, so if you put some in a hydrogen peroxide barrel, the decomposition will not stop until all of it reacted,
the difference with a kipp's apparatus is that it use 2 reactants, so if you stop feeding one in the reaction mixture, once depleted of it the
reaction will stop
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AJKOER
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One of the issues with concentrated H2O2 is the cost of storing it safely and possible cost surrounding its unwanted decomposition.
Research H2O2 detonations, see, for example, https://pdfs.semanticscholar.org/7ae0/2d5db9515693a8c0fe83c4... .
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