Homebrewed equipment for H202 Distillation

[amsci99]

Hi,

Saw this hydrogen peroxide distillation machine at

http://www.tecaeromex.com/ingles/destilai.htm

costs more than 10 grand. Is there a way to homebrew a smaller unit for much less?

[totenkov]

Nah.

I have heard of all kinds of methods of distilling H2O2. I have heard of people having a single piece of dust in their setup and getting blown to all hell. I don't think you will find anything commercially made that is going to be any cheaper.

[ChippedHammer]

Thats pretty cheap when you think about it.

[totenkov]

Oh, yeah I think I've got 10-15 grand in my pocket right now! :)

[s-lab]

from say, 9% H2O2 cant you leave it in a mildly warm place, (not in direct sunlight) so some of the water evaporates to get a stronger soloution?
woukd this work?

[thelasttrueone]

H2O2 also evaporates in my experience (leaving a beaker full of 3% out for a week)

[UnderConstruction]

technically H2O2 doesn't evaporate, it breaks down into hydrogen and water, which is worse in this case because it's not reversible (without re-synthesizing it, obviously). I found a couple of patents for creating & purifying it, they're both very brief and mention "methyl benzyl alcohol", which I guess could be a combination between methyl and benzyl alcohols, but who wants to risk their lives on an idiot mistake like that?

Anyway, here're the two patents:
"Hydrogen peroxide is produced by liquid phase molecular oxygen oxidation of methyl benzyl alcohol, water concentration in the reaction mixture being maintained below 4% by weight, more preferably below 2% by weight, and most preferably below 1% by weight"
http://www.freepatentsonline.com/EP0551929.html

&

"A process is provided whereby the hydrogen peroxide-containing oxidate from methyl benzyl alcohol oxidation is extracted with water and with ethyl benzene extractive solvent and an aqueous hydrogen peroxide phase is separated from an ethyl benzene solvent phase which also contains methyl benzyl alcohol and acetophenone, the improvement being that ethyl benzene is introduced into the extraction zone below the point of introduction of the oxidate, thus avoiding the possibility of formation of an aqueous hydrogen peroxide phase concentrated to a hazardous degree in hydrogen peroxide in the extraction zone. "
http://www.freepatentsonline.com/EP0577372.html

Also look at this:
http://www.patentstorm.us/patents/6337412-description.html

[Charles Owlen Picket]

H2O2 is so cheap and available that (IMO) one should not go to too much trouble to mfg or reconstitute it. If you have written me before, PM me if you have need of a very serious source (50%) which I stumbled upon. However, from a realistic perspective, it is too inexpensive to spend a great deal on it's synthesis.

[kurtz]

from say, 9% H2O2 cant you leave it in a mildly warm place, (not in direct sunlight) so some of the water evaporates to get a stronger soloution?

H2O2 also evaporates in my experience (leaving a beaker full of 3% out for a week)

technically H2O2 doesn't evaporate, it breaks down into hydrogen and water

The vapor pressure of H2O2 is rather lower than that of water, to the point that concentration by evaporation is not difficult, especially considering the presence of stabilizers. BS? See the article starting on page 3307 here -
http://gallica.bnf.fr/ark:/12148/bpt6k90736r
Dude made 66.6% H2O2 just by heating the 4.5% at 75C. His yield was not great and he wasn't working with modern stabilized peroxide in the 1890's, and the decomposition occurs primarily at the higher concentrations. He does some work with vacuum in that article as well.

The vapor above boiling 10% H2O2 (no vacuum) is 99.1% water - not so much because the hydrogen peroxide is decomposing, but because it isn't going anywhere. At 30% it is 95.8%. Of course H2O2 can evaporate, and less concentrated impure peroxide can be distilled with a strong enough vacuum, e.g. JACS 42, 2548 (1920) [first preparation of pure H2O2?] and JACS 48, 3019 (1926) [this one concentrates their distillate from 25% to 88% by standing 3 days in a vacuum desiccator at room temp with H2SO4].

[ETCS (Ret)]

Try heating 3% drugstore peroxide in a stainless steel pan to just below boiling and let it evaporate to approximately 15% of its original volume. When done carefully there will be no discoloration, no bubbling, no smell and no residue.

The end product will be sufficiently strong for the common "uses" for Hydrogen Peroxide.

To test its strength apply a drop to a fingertip and observe the change in skin color.

Several batches may be accumulated in a suitable brown bottle and my be kept for a long time in the freezer.

[Wallybanger]

technically H2O2 doesn't evaporate, it breaks down into hydrogen and water
H2O2 breaks down into Oxygen and water.

[fluoroantimonic]

in a stainless steel pan

Better to use something that will not contaminate the solution with Fe or Cu ions... These are the main catalysts of H2O2 breakdown AFAIK. Well cleaned glass would be best for that but I think aluminum would work well enough. If not put on the stove, I think some plastics such as HDPE will do well too.

If I were going to concentrate H2O2 I would probably fill a 5 gallon bucket or similar container with the dilute H2O2 and put in a warm place (possibly with an electric heater) and use the output of an air compressor to force a stream of air through a filter and then bubbled through it. Even a large aquarium air pump or two could work.. I wouldn't bother with 3% H2O2 though, probably go for 35% hydroponics grade stuff and bring it up to ~75%. Then freeze purify to get >90% for rocketry purposes.

[waveguider]

If I were going to concentrate H2O2 I would probably fill a 5 gallon bucket or similar container with the dilute H2O2 and put in a warm place (possibly with an electric heater) and use the output of an air compressor to force a stream of air through a filter and then bubbled through it. Even a large aquarium air pump or two could work..
If I remember correctly the most efficient method of concentrating HOOH is by the method of air injection/ ''Sparging'' as you describe above.

[megalomania]

I tried that method last year, my results were so-so. The loss rate is a bit high, and it takes too damn long starting from a dilute peroxide concentration. You evaporate a half gallon of water to get a 5% solution. Now the method could certainly be better optimized to process more solution in less time. More air pressure an more bubblers would be one way of cutting the time...

[FUTI]

I had a bottle of old H2O2 somewhere in the lab. It was originally 30% but you all know how it decompose over time (that bottle was about 15 years old). I tested method described here to concentrate it by freezing and it works to some point. I freeze it in the ordinary fridge and after little thawing so that I can remove it out of flask to remove water I separated solid and liquid phase. After measuring densities and naturally testing product with KI I think that I can say that I got around 20% H2O2 and water (very low in H2O2). I know that I could make it better, purpose of my work was to get that damn bottle out of my lab (1), to check can someone actually use this method in his kitchen (2), and I was testing also some synthesis I needed H2O2 for (3). It was several months ago, sorry for reporting that this late. Mega maybe freeze method then "sparging" is a way to go? I heard about sparging but didn't tested ever. Does spray drying sound to crazy explosion risk wise ( from 56% it is reported that even fumes of H2O2 can detonate :-( )? It just cross my mind as an other end of the sparging process... I know that spray drying is used to obtain a solid substance but as older I get I start to accept the fact that unless I didn't seen that or try that I won't reject it works or believe it works. And maybe I just need to make my own device to make my own instant coffee ;-).

[megalomania]

Mega maybe freeze method then "sparging" is a way to go?

That is just what I was thinking. It may be worth a few experiments to see if the initial concentration can be quickly boosted by several percent. The amount of peroxide left in solution is probably comparable to the amount of peroxide lost by sparging, except with the freezing method you technically still have the peroxide in diluted form.