Sciencemadness Discussion Board - Concentrating hydrogen peroxide

Concentrating hydrogen peroxide

kt5000 - 10-10-2014 at 16:30

The hydrogen peroxide I can buy off the shelf is 3-4%. There have been some instances where a more concentrated solution would be very helpful, say 30%. Is there an easy way to concentrate it? Distillation would obviously decompose the H₂O₂. I'm not sure if vacuum distillation might work. I'm almost equipped to do that.

A while back, I read something suggesting bubbling air through a cold H₂O₂ solution would reach concentrations up to 30%. I think the reasoning was this: keeping the solution cool prevents the decomposition, and the air flow increases the rate of H₂O evaporation. That seems too easy. It would depend on the H₂O₂ either not evaporating, or evaporating at a substantially slower rate than the H₂O..

I'm still getting my head wrapped around solubility and properties of solutions, so pardon my noob reasoning here.. Both H₂O₂ and H₂O are liquid at STP and miscible, so we have a homogeneous solution. That solution has a boiling point that is likely somewhere between the BP of the two (100 - 150C). When it evaporates, both liquids will evaporate, but the liquid with the lower BP will evaporate faster. Is that universally true? If so, it seems like the air bubbling method _would_ concentrate the H₂O₂, but may be fairly inefficient.

cyanureeves - 10-10-2014 at 16:43

plante 1999 showed me a way to concentrate peroxide using an aquarium pump aerator.the peroxide was warmed just below boiling point on a candle wax warmer or coffee pot(180 deg.) the air was bubbled until 1/3 of peroxide is left. i know it works because i left it unattended for a couple of hrs. and when i got back,the stone at the end of the air tube was totally dissolved.the peroxide had also evaporated so i abandoned this before i get burnt or something.

Hawkguy - 10-10-2014 at 16:44

There are two main methods to concentrating Hydrogen Peroxide, like the pharmacy stuff.
-The first way is to heat to maybe 50 - 80 degrees Celsius, and water will evaporate off. The point is to steam off the water, so not boiling or even slight simmering should take place. This way is also dangerous, as oxygen is released in small quantities, larger if the heating goes wrong.
-The second method involves leaving the Hydrogen Peroxide solution in a beaker or crystallizing dish, in a warm room. It should be covered, or in a desiccating bag. The idea is for the water to slowly evaporate, and leave behind a more concentrated product. It should be left for a week or several, depending on goal.
Good luck!

kt5000 - 10-10-2014 at 16:53

Quote: Originally posted by cyanureeves

when i got back,the stone at the end of the air tube was totally dissolved.the peroxide had also evaporated so i abandoned this before i get burnt or something.

The method I read of used an aquarium stone also. So maybe bubble through a glass pipette instead of the aquarium stone?

kt5000 - 10-10-2014 at 16:55

Quote: Originally posted by Hawkguy

This way is also dangerous, as oxygen is released in small quantities

The oxygen being dangerous, is that only if I'm using an open flame, or does it form some other compound? I heat everything with an electric hotplate.

cyanureeves - 10-10-2014 at 17:01

no kt5000 the idea was not to get it to 30% concentration but since i let it go further it's concentration went way higher.i was looking for 15-30% but it went higher so i got careless and so obviously i'm not ready for this crap! i was going to make ammonium iron sulfate.

Hawkguy - 10-10-2014 at 17:09

Quote: Originally posted by kt5000

Quote: Originally posted by Hawkguy

This way is also dangerous, as oxygen is released in small quantities

The oxygen being dangerous, is that only if I'm using an open flame, or does it form some other compound? I heat everything with an electric hotplate.

No other compounds are formed, just that the oxygen makes the ignition of a nearby flammable material much more likely, as I have found out from experience. You'll be fine if you use clean apparatus, a neat workspace, and if you SLOWLY heat the Hydrogen Peroxide. Remember, it should be steaming like a hot tub in the winter, no excessive heat should be used.

blogfast25 - 11-10-2014 at 06:35

You can also concentrate peroxide solutions by freezing them. There's a thread on it here somewhere.

hyfalcon - 11-10-2014 at 06:39

This topic has been covered extensively on the site. Does no one search anymore before starting a new thread?

CuReUS - 11-10-2014 at 08:30

Quote: Originally posted by hyfalcon

This topic has been covered extensively on the site. Does no one search anymore before starting a new thread?

correct, this is the link to that thread
http://www.sciencemadness.org/talk/viewthread.php?tid=30193#...

hyfalcon - 11-10-2014 at 09:44

I had this in mind myself.

Code:

https://www.google.com/search?q=site%3A+sciencemadness.org+hydrogen+peroxide&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=sb#rls=org.mozilla:en-US:official&channel=sb&q=site:sciencemadness.org+concentrating++hydrogen+peroxide

Got it that time.

[Edited on 11-10-2014 by hyfalcon]

[Edited on 11-10-2014 by hyfalcon]

franklyn - 11-10-2014 at 12:26

http://www.sciencemadness.org/talk/viewthread.php?tid=1325
http://www.sciencemadness.org/talk/viewthread.php?tid=1325#p...

P.S.
stay away from partitionong with ether unless you're willing to end up as red mist.

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