Jump to content


Photo
- - - - -

Concentrating Hydrogen Peroxide


  • Please log in to reply
22 replies to this topic

#1 Sebbass69

Sebbass69

    Quark

  • Members
  • 26 posts

Posted 20 April 2009 - 11:50 PM

I've seen a lot of information about concentrating both the 3% versions of hydrogen peroxide, and the 30%. I've seen the idea of boiling it (bad idea, due to vapor detonation), and I've seen freezing it (which seems somewhat less explosive) - however can someone explain to me the fine points of freezing hydrogen peroxide, and then removing the concentrated product. If I had the 3% solution, what temperature would it freeze at, and how would I remove the concentrated product, and what concentration would it be. If I use the 30% version (I would prefer this infinitely, as it would give me more peroxide, and I have no problem getting 30% Hydrogen peroxide) - again, the same questions as with the 3% variety.

As a disclaimer, please note that concentrated hydrogen peroxide is corrosive (especially to eyes) and is a very strong oxidizer - it should only be handled with appropriate safety equipment, and under the supervision of someone who is familiar with it's properties.
  • 0

#2 John Cuthber

John Cuthber

    Chemistry Expert

  • Resident Experts
  • 8,905 posts
  • LocationEngland

Posted 21 April 2009 - 06:33 PM

"it should only be handled with appropriate safety equipment, and under the supervision of someone who is familiar with it's properties."
So, not by you then.
  • -1

#3 Sebbass69

Sebbass69

    Quark

  • Members
  • 26 posts

Posted 21 April 2009 - 11:35 PM

... actually, no that is not correct - I work in a school lab with my teacher, who is intimately familiar with it's properties - not to mention I have full gloves, goggle, apron, jump shower and vent hood at my house so even if I wasn't at school, I would still have appropriate equipment

Perhaps we should have complete information before we go making snide responses, eh?
  • 0

#4 Patrick Henry

Patrick Henry

    Quark

  • Members
  • 23 posts
  • LocationEarth

Posted 22 April 2009 - 07:38 AM

I've never really tried to concentrate H202—most substances tend to react with it and make it decompose... sorry, I don't know the answer, but don't hesitate to share your results afterwards!
  • 0
The future belongs to those who believe in the beauty of their dreams. --Eleanor Roosevelt

#5 CaptainPanic

CaptainPanic

    Usually himself

  • Moderators
  • 4,540 posts
  • LocationThe little swamp at the end of the river Rhine

Posted 22 April 2009 - 09:09 AM

... actually, no that is not correct - I work in a school lab with my teacher, who is intimately familiar with it's properties - not to mention I have full gloves, goggle, apron, jump shower and vent hood at my house so even if I wasn't at school, I would still have appropriate equipment

Perhaps we should have complete information before we go making snide responses, eh?


It's true that you have nice protective stuff, but none of those mentioned help in case of an explosion.

You're dealing with a potential detonation here, as you mentioned yourself - not just some spilled acid which can ruin your clothes.
  • 0
Veni, vidi, modeli - I came, I saw, and I modeled it

#6 Theophrastus

Theophrastus

    Atom

  • Senior Members
  • 300 posts
  • LocationCanada

Posted 22 April 2009 - 08:44 PM

I'm not sure of freezing, however, I do know that adding heat, will only increase the rate of decomposition, will it not, so technically, in boiling it down, it won't concentrate the solution due to the peroxides decomposition, which is rather unstable, at high temperatures, as many have already pointed out. There's good reason why people don't simply boil the peroxide, down to jet fuel concentrations. Because not only is it futile, but you run the risk of injuring yourself and those around you.

Edited by Theophrastus, 22 April 2009 - 08:47 PM.
addition of content

  • 0

#7 Sebbass69

Sebbass69

    Quark

  • Members
  • 26 posts

Posted 23 April 2009 - 01:04 AM

It's true that you have nice protective stuff, but none of those mentioned help in case of an explosion.

You're dealing with a potential detonation here, as you mentioned yourself - not just some spilled acid which can ruin your clothes.


Right, but as I said, I won't be heating the solution, as that would lead to an explosion.... as far as I am aware, the peroxide won't detonate unless heated...
  • 0

#8 person

person

    Meson

  • Senior Members
  • 76 posts

Posted 25 April 2009 - 01:59 PM

H2O2 has a boiling point of just over 150 deg c. The decomposition occurs more rapidly in alkali, so acid is often added as a stabilizer. Heat does increase decomposition but not as much as you would be evaporating off.

H2O2 can detonate above 70% so unless you boil off more than half your 30% Soln and asuming no H2O2 decomposed during this process (wich it would have) it should be fine. Also you dont have to heat the soln to boiling point you can just increase the heat (70-80) to evaporate off the water.

Alternately you can solidify the water out. H202 has a Freezing point of about half a deg less than H2O therefore as soon as you get any ice crystals forming you filter them out. The remianing soln will be more concentrated. (this process can then be repeated a few times)
  • 0
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -Einstein

There are 10 types of people in the world, those who understand binary code and those who don't.

#9 John Cuthber

John Cuthber

    Chemistry Expert

  • Resident Experts
  • 8,905 posts
  • LocationEngland

Posted 25 April 2009 - 02:52 PM

... actually, no that is not correct - I work in a school lab with my teacher, who is intimately familiar with it's properties - not to mention I have full gloves, goggle, apron, jump shower and vent hood at my house so even if I wasn't at school, I would still have appropriate equipment

Perhaps we should have complete information before we go making snide responses, eh?


Since you are asking about its properties I think it's fair to say that you are not familiar with them. Since you also think that you need to heat the stuff to get it to detonate (you don't) and that an apron etc. will do you any good (it won't) then I think my remark is fair comment.
  • 0

#10 Sebbass69

Sebbass69

    Quark

  • Members
  • 26 posts

Posted 27 April 2009 - 04:42 PM

Since you are asking about its properties I think it's fair to say that you are not familiar with them. Since you also think that you need to heat the stuff to get it to detonate (you don't) and that an apron etc. will do you any good (it won't) then I think my remark is fair comment.


Fair enough - but you're still forgetting that I'm going to be working with my teacher, who is a professional, and would provide the required equipment -

You are right about one thing - I was asking about it's properties, so I would have some idea of how to do this....

Additionally, no MSDS on 90% H2O2 lists it as an explosive - it says
"Product is non-combustible. On decomposition releases
oxygen which may intensify fire. An explosion hazard when mixed with organics at high concentrations." That's why I thought it wouldn't explode by itself unless heated - I knew it could explode when mixed with flammable / combustible material, but if you have other experience, then thank you for the information -

As for your remark, it could have been more polite - wisdom is not a substitute for manners, nor is it an excuse to be rude.
  • 0

#11 Mr Skeptic

Mr Skeptic

    iDon't-Believe-You

  • Moderators
  • 8,309 posts
  • LocationDunkirk, NY

Posted 27 April 2009 - 04:56 PM

Mix some manganese dioxide powder into it and then freeze it. That should be fairly safe.
  • 1
Our voting system is broken! It nearly guarantees that we will have only two political parties that have any chance of winning, and that they will be very similar.

#12 UC

UC

    ydoaPs just lost the game

  • Senior Members
  • 550 posts
  • LocationNew Jersey, USA

Posted 27 April 2009 - 06:20 PM

Additionally, no MSDS on 90% H2O2 lists it as an explosive - it says
"Product is non-combustible. On decomposition releases
oxygen which may intensify fire. An explosion hazard when mixed with organics at high concentrations." That's why I thought it wouldn't explode by itself unless heated - I knew it could explode when mixed with flammable / combustible material, but if you have other experience, then thank you for the information -


AFAIK, it's not a true "explosive" so much as it vigorously and violently decomposes when catalyzed. If you were to put 90% H2O2 in an erlenmeyer containing even traces of copper, silver, manganese, etc. ions, you would readily make a rocket engine of several hundred degree steam and oxygen gas. chances are the erlenmeyer would shatter and scalding steam, peroxide, and glass would go be ejected in all directions, such as into your face.

I don't believe you're working in a school lab at all. I think this is BS to cover your arse.

High concentration H2O2 is made by reduced-pressure fractional distillation in dedicated glass apparatus, IIRC.
  • 0

#13 Sebbass69

Sebbass69

    Quark

  • Members
  • 26 posts

Posted 28 April 2009 - 04:21 PM

AFAIK, it's not a true "explosive" so much as it vigorously and violently decomposes when catalyzed. If you were to put 90% H2O2 in an erlenmeyer containing even traces of copper, silver, manganese, etc. ions, you would readily make a rocket engine of several hundred degree steam and oxygen gas. chances are the erlenmeyer would shatter and scalding steam, peroxide, and glass would go be ejected in all directions, such as into your face.

I don't believe you're working in a school lab at all. I think this is BS to cover your arse.

High concentration H2O2 is made by reduced-pressure fractional distillation in dedicated glass apparatus, IIRC.


Whether or not you believe me is irrelevant - you're belief or disbelief does not make it true or untrue - however I assure you, I work in a school lab -

Merged post follows:

Consecutive posts merged
I forgot to say - from what everyone tells me, it seems that actually concentrating H2O2 isn't really feasible without specialized equipment, so I think it's safe to say it would be foolish to attempt it - my school is good, but they don't have vacuum distillation apparatus that can handle H2O2 - that and from what you guys say, it's explosive, so I think it would be best to wait on this one -
Anyways, thanks for all of the advice guys -
  • 0

#14 John Cuthber

John Cuthber

    Chemistry Expert

  • Resident Experts
  • 8,905 posts
  • LocationEngland

Posted 28 April 2009 - 06:35 PM

Your belief in your teacher's wisdom wouldn't stop the stuff decomposin so I'm glad you have decided against this experiment.
  • 0

#15 dr.syntax

dr.syntax

    Banned

  • Banned
  • 418 posts

Posted 3 October 2009 - 01:41 AM

"it should only be handled with appropriate safety equipment, and under the supervision of someone who is familiar with it's properties."
So, not by you then.

REPLY: John Cuthber is right
Why are you asking the questions you do. It`s an explosive you know. A very unstable and therefore dangerous one.

#16 iNow

iNow

    SuperNerd

  • Senior Members
  • 14,388 posts
  • LocationAustin, Texas

Posted 3 October 2009 - 01:54 AM

Considering it's been more than five months since they asked, your response will probably not be heeded.
  • 0

#17 dootsmasta

dootsmasta

    Lepton

  • Members
  • 1 posts

Posted 16 November 2009 - 11:06 PM

Stick to the subject, please. If you feel uneasy about the intentions of the person making the original post, click the X in the corner of the window.
  • 0

#18 insane_alien

insane_alien

    Genius

  • Senior Members
  • 10,094 posts
  • LocationScotland

Posted 16 November 2009 - 11:12 PM

you joined these forums just to necromance that?
  • 0
Tired of waiting around for a reply on the forums? Use IRC, 'I don't know how' is no longer an excuse.

"Special" Relativity, stupid ideas seem smarter when they come at you really fast.

#19 rogerxd45

rogerxd45

    Meson

  • Senior Members
  • 164 posts

Posted 23 January 2010 - 11:35 PM

"it should only be handled with appropriate safety equipment, and under the supervision of someone who is familiar with it's properties."
So, not by you then.


why is everyone here like this? instead of answering the question they just say "dont do it"
  • 0

#20 insane_alien

insane_alien

    Genius

  • Senior Members
  • 10,094 posts
  • LocationScotland

Posted 23 January 2010 - 11:56 PM

because if someone goes an burns themselves or loses a finger there is a chance that they will try to blame us for supplying the info to do it. we do not particularly like getting sued.

plus, it always pays to be safe. we are not going to tell some numpty that clearly doesn't know which shoe goes on which foot how to make dangerous substances.
  • 0
Tired of waiting around for a reply on the forums? Use IRC, 'I don't know how' is no longer an excuse.

"Special" Relativity, stupid ideas seem smarter when they come at you really fast.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users