Sciencemadness Discussion Board - h202 concentration?

h202 concentration?

SeSteMyBe - 7-1-2004 at 17:25

i have hade small amount of acetone peroxide before using 10 % h202. i looked around for a while so dont flame me please. i need a way to concentrate mt 10 % h202 to around 30%( the higher the better) i have 6 gallons of 10% h202 and would rather concentrate it than buy a higher concentration. any ideas that can be done to concentrate it? ive heard of evaporation and some way with elecrosis. any help is greatly apriciated thank you

Haggis - 7-1-2004 at 18:03

It can be concentrated by boiling at 100 degrees to about 112 degrees. Keep it as low as possible. It has worked fairly well for me.

tom haggen - 7-1-2004 at 18:23

I can't wait to get a hot plate. So I can control the temperature perfectly.

[Edited on 8-1-2004 by tom haggen]

Mendeleev - 7-1-2004 at 19:18

If you feel like being cheap and wasting some time monitoring temperature, you can buy a duraband single burner, aka hot plate, at Wal-Mart for ~ $9.

AngelEyes - 8-1-2004 at 02:10

I was under the impression that boiling H2O2 was not the best way to concentrate it, as you inevitably lost O2. Apparently, though, you can freeze it. You'll end up with a lump of ice in liquid. This liquid should be about 50% peroxide iirc. The ice is of no use.

a_bab - 8-1-2004 at 05:56

Actually, the ice contains some of the H2O2, but probably less then 3 %. And the liquid is not that concentrated, it's maybe 20-25 %.

I have a method for concentrating H2O2 up to around 90% if anyone interested.

Saerynide - 8-1-2004 at 08:40

Lets hear it... not that Im gonna try killing myself making it

DDTea - 8-1-2004 at 11:57

Oh cut the suspense and just post it! I'd be up for makin it. What for? No idea, but it seems neat to have a bit of it around. NO FEAR

Haggis - 8-1-2004 at 12:00

I would love to hear your method. However, amature experimenters must keep in mind that distilling hydrogen peroxide at high concentrations like that can go catastrophically wrong when a small amount of organic material violently decomposes the entire lot of peroxide. I don't know if one could ever get their apparatus absolutely clean, I've always had a problem keeping my supplies spotless. Another method is to produce the hydrogen peroxide from a reaction with sodium peroxide.

I am a fish - 8-1-2004 at 13:13

WARNING: The following procedure is stupidly dangerous and should not be attempted under any circumstances

Hydrogen peroxide can be concentrated by shaking it with diethyl ether. A layer of ether mixed with hydrogen peroxide will form, which can be seperated off. The hydrogen peroxide can then be isolated by boiling off the ether.

guaguanco - 8-1-2004 at 13:53

Quote:

Originally posted by I am a fish
WARNING: The following procedure is stupidly dangerous and should not be attempted under any circumstances

Hydrogen peroxide can be concentrated by shaking it with diethyl ether. A layer of ether mixed with hydrogen peroxide will form, which can be seperated off. The hydrogen peroxide can then be isolated by boiling off the ether.

That's so suicidal it's just plain funny!

Haggis - 8-1-2004 at 14:49

Really clever, did you think of it yourself? Damn...good idea and advice, but not that the info's out, some k3wl with a can of starting fluid and some 3% will try out "something I learned on the internet". Peroxides of ether are fun.

guaguanco - 8-1-2004 at 15:02

some interesting info

purification
hey, look at this!

[Edited on 8-1-2004 by guaguanco]

Mendeleev - 8-1-2004 at 17:16

There are three ways of concentrating hydrogen peroxide, one as was mentioned is distilling. It would be preferable to distill at 40 C under vacuum. If anybody needs a cheap vacuum pump go to http://www.sciplus.com (I get all my supplies from there because it is the cheapest source around even if they don't have the greatest selection, but they do have some nice 85 pound lifting capacity ceramic magnets

) Freezing was also mentioned. Below 62% water freezes before hydrogen peroxide, but after 62% hydrogen peroxide freezes before water. So quite high concentrations can be achieved if you freeze it to 62%, throw out the ice and then freeze it again, this time keeping the ice which is now relatively pure hydrogen peroxide. Another method is sparging, which involves bubbling warm dry air through a hydrogen peroxide solution. You can buy bernzomatic oxygen tanks at home depot or lowes for about $8 a tank. If you have a good vacuum pump I would recommend distilling as it guarantees the highest concentration. Heres a website I found while searching google with some nut's design for a hydrogen peroxide distillation rig http://webhome.idirect.com/~earlcp/Reports/Stills_199x.html Doesn't this thread belong in the reagents and apparatus aquisition section?

[Edited on 9-1-2004 by Mendeleev]

I am a fish - 9-1-2004 at 03:59

Quote:

Originally posted by Haggis
Really clever, did you think of it yourself? Damn...good idea and advice,

I believe that seperation with ether was once used industrially to concentrate H2O2. For obvious reasons, it is not used today.

Quote:

but not that the info's out, some k3wl with a can of starting fluid and some 3% will try out "something I learned on the internet". Peroxides of ether are fun.

There are plenty of stupidly dangerous procedures described on this forum.

KABOOOM(pyrojustforfun) - 9-1-2004 at 13:55

peroxides of ether form from O2 not H2O2 (but it can accelerate it by its degradation to O2

maybe a second extraction with CH2Cl2 could remove the peroxide? this method could probably be used to make in situ binary explosives.
what is the ratio of H2O2/ether in the extract?

H2o2

Jsmooth744 - 18-1-2004 at 15:49

Just boil it in a pan over the over until it gets 1/10th of the way down then you have concentration between 20-30% I assume your boiling down 3%.

Hermes_Trismegistus - 18-1-2004 at 18:28

Quote:

Originally posted by Mendeleev

Your method sounds very workable with one minor change. You'd want to "bridge the gap".

Freeze concentrate, removing water ice until concentration reached a suitable 50ish% and then evap to 70ish% and then freeze concentrate collecting H.perox.Ice until 90+% and then distill till ya get the hi-test!

The freezing points are just too close between 55% and 65% to be able to cross the barrier w/out massive losses.

Lookit Guaguanco's chart.

froot - 19-1-2004 at 00:21

Once I left a small amount of 50% H2O2 on a plate to dry. A couple of days later the volume had decreased to an oily liquid. I had no use for it so I discarded it in a pot plant. I was quite alarmed by the commotion it caused. It was violently oxidising any organic material it came in contact with, so much so that even the sand was glowing from the heat. The stuff must have been seriously concentrated by simple evapouration, great if you have the time.
I live in a fairly dry climate, and I'm not sure if H2O2 is a water scavenger so it might/not work in a humid climate.

ps, If you have concentrated H2O2, keep it clean and away from everything. Treat it like a god, or it could really spoil your day.

[Edited on 19-1-2004 by froot]

Saerynide - 19-1-2004 at 01:28

Do you have a picture of what the plant looked like after?

froot - 19-1-2004 at 04:39

Nope I don't unfortunately. Out of curiosity, why would one want to concentrate H2O2 to near 100% in the first place?
-unless:- could one form pure HNO3 from bubbling NO2 through pure H2O2??

[Edited on 19-1-2004 by froot]

Saerynide - 19-1-2004 at 05:39

I dont wanna make 100% h202, not even above 50%. I seriously do not want my house catching fire

I am a fish - 19-1-2004 at 09:41

Quote:

what is the ratio of H2O2/ether in the extract?

I have no idea. Please don't try it.

Mendeleev - 19-1-2004 at 09:56

100% hydrogen peroxide is needed to make very high end explosive, some furazans and furoxans, hexanitrobenzene, and some nitroureas, it is also needed for hydrogen peroxide rockets.

Iv4 - 20-1-2004 at 02:50

I've tried both evaping and freezing and untill now didnt know whats wrong:

with evaporation temp control is prety hard on the burner(gas).Though since I only had a stainless steel pan didnt wan to risk anything.

I tried freezing it but all the 4 times I tried just frize the whole damn thing.

PS
You sure about peroxide in rocktes,russian torpdo's use 60% I think.

ALso syrian rockets use 60% mixed with diesel ethanol and some sugar

froot - 20-1-2004 at 06:53

The Germans used hydrazine hydrate and hydrogen peroxide in manned rocket planes, this was their answer to cheaper aerial combat. They would shoot these poor buggers off in these 'planes' to go shoot down allied planes. The rocket engine only lasted a few minutes so he had to make the most of his trip and then try and safely glide the thing back to the field.
The project was cancelled when one crashed and the tank holding the hydrazine burst and half dissolved the poor pilot. Incredible!

Saerynide - 20-1-2004 at 10:28

Edit: Off topic, but....

Wouldnt he have died from the crash first?

[Edited on 20-1-2004 by Saerynide]

Uses for h2o2 go WAY back.

Hermes_Trismegistus - 20-1-2004 at 15:05

I seem to remember that the Japanese used a couple mini-subs using h202 as fuel component in the subs that attacked pearl harbor and that the British had used a similarly designed sub (during WW1?) that used peroxide. I saw a layout about it in National Geographic.

Quote:

Originally posted by Saerynide
Edit: Off topic, but....
Wouldnt he have died from the crash first?

[Edited on 20-1-2004 by Saerynide]

I wonder how they explained that to the relatives?...(sending the body home in a jug)

Saerynide - 21-1-2004 at 00:20

Ewwwww.... =S

Theoretic - 21-1-2004 at 07:26

Another way to concentrate H2O2 is to add an anhydrous salt that forms hydrates readily. For example, calcium chloride. 110 grams will absorb 108 grams of water (on formation of hexahydrate), and I bet it will settle out as (easily filtrable) crystals.

simsalabin - 30-1-2004 at 01:13

what about freezing ?
it freezes at -35 celisus.
boiling h2o2 will cause degradation

chloric1 - 30-1-2004 at 19:17

Break out the Dry ice and Acetone freezing mixture!And keep the peroxide out of the acetone!

[Edited on 1/31/2004 by chloric1]

.....mmmmmuuuugggghhhh!..... aspirator (homer)

Hermes_Trismegistus - 30-1-2004 at 19:29

Quote:

Originally posted by simsalabin
boiling h2o2 will cause degradation

Boil at reduced pressure.

Ramiel - 31-1-2004 at 02:35

Theoretic: kewls remember to use regular, and not glass filtering paper when filtering dehydrated solutions of 90% H2O2

But seriously - won't high conc. peroxide attack glass fibre even?

vulture - 31-1-2004 at 14:09

Glass fibre is a no no as filter material. It's a tiny bit basic, so...

If you're going to distill H2O2, you're going to need to clean your glassware with concentrated HNO3. After that with H2SO5 and finally rinse it with diluted H2O2. Then add some phosphoric acid as stabilizer.

jimwig - 6-2-2004 at 13:30

Hey there ----mr a-bab, what about putting up that "90% H2O2" regime........

BromicAcid - 24-11-2004 at 21:33

The other day at the library I was looking though some book and actually ran across a reference that said solutions of hydrogen peroxide in ether are more stable then those in water... odd...

Anyway, I just found out some interesting information about the peroxide that I normally use. I buy it from a hair care place and it says on the bottle 40 volume Hydrogen Peroxide, I always assumed that either meant it was near 40% or perhaps it was done same as alcohol and 40 volume was like a proof and it was actually 20% so today I did some checking and found the actual concentration.

10 volume = 3% H2O2
20 volume = 6% H2O2

And etceteras, so, my H2O2 is only around 12%, very disappointing, I guess I might have to concentrate by freezing. Oh well, it's getting cold out. I really have no need for anything above 30% and solutions stronger then that kind of give me the creeps considering I've seen this 12% stuff I normally work with behave very strongly toward what I would consider mild conditions.

Aside from that, it was mentioned that one might use anhydrous salts to sap the water from a hydrogen peroxide solution, wouldn't many salts simply uptake the peroxide in place of water to form the hydrate, I know some salts do, but do they all?

Edit: One other thing, I've heard that barium peroxide can be precipiated from cold water, this seems to be supported by it forming a stable octohydrate and that hydrate having a temperature at which it looses its water of hydration, but does anyone have any experience with this?

[Edited on 11/25/2004 by BromicAcid]

S.C. Wack - 25-11-2004 at 00:42

I went to the library last Sunday to look up the ozone via H2SO4 electrolysis refs. Not that I have Pt electrodes, just curious. The only peroxide sp. gr. tables that I had were in 10% increments, so I wrote down what was in one of the refs that I stumbled on while doing so. I think that this was at 16C: 20% = 1.0725, 25% = 1.0918, 30% = 1.1122, 35% = 1.1327, 40% = 1.1536, 45% = 1.1749.

I've made small amounts of the Ba and Na peroxide hydrates from the hydroxides and H2O2. Not sure how well these dry out, at least without P2O5 in the vacuum dessicator. But they do precipitate very nicely out of the H2O2 and are easily isolated quickly. I seem to remember reading somewhere that heating without vacuum gives loss of O as well as water, so I haven't tried that.

One of the books that I scanned and uploaded to axehandle, Oxidations in Organic Chemistry, mentions the preparation of anhydrous H2O2 in Et2O from the 30% peroxide if anyone ever needs such a thing.

I make all of my peroxide now, in not small amounts, from drugstore 3%. I hoard it when it is on sale, 3 pints for $1. I used to just let it evaporate because with the stabilizers and all, if you use big clean (buffed to a polish) glass mixing bowls then dust is not a problem. Even 35% can have a bunch of dust on it and not bubble at all. Yields were high. Metal is another story. But then I found that heating below 70C will concentrate to 45% with little loss of O2.

I've tried the freezing yet I use heating. But that's me.

Don't know if this has been mentioned before, but the volume thing is based on how much O can be released from 1 ml of the peroxide; e.g. 1 ml of 3% H2O2 can release 10 ml of O.

Off topic, but the only other thing that happened at the library Sunday, other than the peroxide refs (and being required to present photo ID in addition to my library card!) was accidentally stumbling onto an interesting Na production lecture demonstration from JCE. Looks like Cyrus was onto something when he mentioned using light bulbs in the unconventional Na thread, sort of, but he got no love. I uploaded it to axehandle as na_from_nano3_and _a_light_bulb.pdf. Someone might want to see exactly how much Na a light bulb could produce if left on long enough. I paid too much for mine to not use it, so it's up to someone else.

[Edited on 25-11-2004 by S.C. Wack]

Axt - 25-11-2004 at 21:34

Ive shaken H2O2 with ether, I think you would have a hard time hurting yourself with the mix, unless there is crystals floarting around in it. Though apart from burning myself with the extract I havnt pursued it further. Oh, I was using 50% H2O2 in ether as well, so more "dangerous".

Another thought, Is pure silica gel inert towards H2O2? Another attempt I made to concentrate the 50% was by pouring it over silica gel containing blue/pink indicator The prills exploded as it catalysed the breakdown of the H2O2.

By soaking the prills in H2SO4, to try and kill the indicator, washing them with water and drying for 1.5hr at 150° there was no more blue colour. These prills only slowly attacked the H2O2. So im thinking the indicator is the problem, but it could also be explained by residual H2SO4 stabalising the mix (which it DOES do with the gel).

So someone may want to try adding H2O2 to pure silica gel (pull it out of a shoebox or something), sodium silicate works to concentrate H2O2, but its soluble. Imagine pouring H2O2 into the top of a tube filled with silica gel and concentrated H2O2 exiting out the bottom, this seems to good to work

rocketscience - 25-11-2004 at 22:32

If you need 100% h2o2 I would recommend making the 90% pure and adding ether potassium superoxide or sodium peroxide to it they would chemical react with the remaining water to make h2o2 the I would let it evaporate in a still however ko2 and na2o2 are expensive and in order to make yourself you have to take pure na or k and burn it with pure oxygen

Polverone - 26-11-2004 at 00:09

The indicating silica gel uses cobalt chloride to do its indication, and of course cobalt compounds effectively catalyze H2O2 decomposition. Adding alkali metal peroxides or superoxides to H2O2 to bring it to 100% sounds like a recipe for disaster. H2O2 decomposes more rapidly in alkaline conditions, and of course it wouldn't be pure even if it didn't explode because it would have sodium or potassium compounds left in it.

budullewraagh - 26-11-2004 at 06:17

i heard before something about bubbling NO2 into conc H2O2 to form HNO3...can that happen? or do you need a platinum catalyst?

Esplosivo - 26-11-2004 at 12:24

NO2 dissolves in water giving a mixture of nitric (III) and nitric (V) acids, i.e. HNO2 and HNO3 respectively. H2O2 oxidizes the HNO2 to HNO3 - no need of any catalyst IIRC. As a side note, but wouldn't that be a 'waste' of H2O2. HNO2 is oxidised to HNO3 by bubbling air through the solution.

budullewraagh - 26-11-2004 at 14:08

i see. bubbling air?

FrankRizzo - 28-11-2004 at 15:22

Dry air, specifically.

budullewraagh - 28-11-2004 at 15:28

eh...so sorta using pressure or something?

BromicAcid - 28-11-2004 at 19:26

It's just the oxygen in the air oxidizing the nitrous acid thus formed and any nitrogen monoxide to allow more of the nitrogen dioxide entering the solution to be absorbed as nitric acid.

FrankRizzo - 29-11-2004 at 11:55

You'd want to bubble air from a common air pump (fish aquarium pump would work fine) through a drying tube containing calcium sulfate or a similar desiccant, into your NO2 contaminated acid. Make sure that the tubing that you're using is acid resistant as well (PTFE).

BromicAcid - 1-12-2004 at 18:27

Stirring a solution of H2O2 during freezing seems to be a good thing in that it will allow for better heat conduction in the solution and result in smaller pieces of ice which could be filtered from the solution and reduce the risk of a solid sheet forming across the top and breaking a beaker.

However by that same process the freezing point will be depressed somewhat due to the motion and if the stirring is too high could an even higher percentage of the peroxide end up in the ice? How about adding a piece of ice once it gets sufficiently low in temperature to function as a seed crystal?

I haven't found answers to these little questions in my little excursion into peroxide concentration and I was hoping someone could help.

Found another hydrogen peroxide FAQ

Eclectic - 1-12-2004 at 21:54

A rotovap does a fine job of concentrating 30% H2O2 to better than 70%. There is a much bigger diference in the boiling points than there is in the freezing points.

mick - 7-2-2005 at 11:00

I have not seen this mentioned anywhere here and I have not prepared it but it sounds interesting.

Being an organic chemist, stable oxidisers with organic chemicals are useful.

Hydrogen peroxide- urea compound

It is used as an alternative to 90% H2O2
As a source of anhydrous H2O2 in oxidation reactions.
Soluble in water and alcohols, low solubility in organic solvents such as DCM.
Prepared by recrystallizing aqueous H2O2 with urea.
The pure material needs to be kept cold etc
The 90% material, I assume the rest is is urea, is OK at RT but it states that it can be made to detonate under forcing conditions.
Decomposition accelerates at it MP (80 ish).
Recommends the stuff is used behind a blast screen.
It could be safer, easier to store and easier to handle than pure H2O2.
Could be wrong.
mick

The 90% commercial stuff might have an inert filler to increase its stability

edit mick

[Edited on 7-2-2005 by mick]

[Edited on 7-2-2005 by mick]

Mumbles - 7-2-2005 at 14:30

I've made this compound before. I made it before I knew all it's oxidising strength. I may still have a small sample around. It was said to form a touch sensitive explosive in contact with Sodium dithionite(Na2S2O4). The proceedure was originally on Lagen's page, under the title of Carbamide peroxide. The reaction was smooth and pretty simple actually. I can post the synth if anyone wants it.

Concentrating hydrogen peroxide.

h0lx - 7-1-2006 at 01:12

I am looking into getting some high concentrated hydrogen peroxide and I was wondering how fas should I evaporate water and since what concentration would be optimal to start dessicating? I am using 50% H2O2 for starting.

Marvin - 7-1-2006 at 03:34

Sure that is 50% and not 50 volume btw?

This has been covered before, but intended for much lower concentrations. My personal opinion is that dessicating is your only option for something that high.

Somewhere I had concentration limits by freezing, but I think you are neerly out of that range.

garage chemist - 7-1-2006 at 06:10

Vacuum distillation would be the fastest and most economic way.
I have done it before to make some 80% H2O2. The concentration can reach over 90% when enough water / dilute H2O2 is distilled off.
You need to use a boiling capillary, otherwise severe bumping will occur.
A column is also highly recommended.

If no vacuum still is available, you can use sparging: bubble hot air (aquarium air pump + dust filter + air heater (heated copper pipe through which the air is led)) through the H2O2 inside a narrow- necked container (to minimize contamination with dust) until the level of liquid has dropped the right amount. Keep in mind that at the end the evaporation a lot of H2O2 begins evaporating. You will have to evaporate 50% H2O2 to ca. 20% of its original volume to obtain over 90% H2O2.
30% H2O2 needs to be evaporated down to about 10% of its original amount.

neutrino - 7-1-2006 at 08:30

How much of a problem is decomposition in these methods? I would think that heating hydrogen peroxide would cause a good deal of it.

h0lx - 8-1-2006 at 01:17

Hmm, If it's recomendable to dessicate from there, I think I will buy some 70% peroxide, which is more costy though, but less work concentrating it. I don't have a Vacuum still, limited to normal distillation. BTW, how far can it be concentrated by dessicating, what is the maximum?

denatured - 8-1-2006 at 20:37

if some kind of stabilizer is added(like Na pyrophosphate) ... would that reduce the loss?

kABOOM! - 9-1-2006 at 21:40

Go to a hydroponics store...they should sell HydroX or 35-40% H2O2. It is added to water to promote oxidation of plants/ anti bacterial solution for water. Also known as OxyShock....

I have 100 L of the stuff. Freakin' corrosive stuff!

lordmagnus - 10-1-2006 at 19:53

Those cheap hotplates can be enhanced a little, bypass the bi-metal thermostat unit on the front, and put a 1000 watt light dimmer (lutron makes them, try home depot) inline on the cord, those hotplates are usually on 800 watts or so. This will allow you much more precise control of the heating element (It is a resistive load, just like a light bulb).

agent_entropy - 23-9-2006 at 15:31

So what sort of filter SHOULD be used for filtering the ice out of H2O2 when concentrating by the freezing method? Above it is mentioned that glass filters should NOT be used, but regular filter paper is, well, paper (organic material); won't the H2O2 attack it?

About the sparging method... above, both air (from an air pump) and pure oxygen (bernzomatic) are suggested for use in bubbling through the peroxide to be concentrated. I expect that there is some benefit to using oxygen rather than air? (2 H2O2 -> 2 H2O + O2 ... keeps the equilibrium to the reactant side?)

PS. I can't seem to find the vapor pressure of pure H2O2, any help is appreciated.

not_important - 23-9-2006 at 21:54

CRC handboook

1 mm @ 15,3 C
10 mm @ 50,4
40 mm @ 77
100 mm 97,9
400 mm @ 137,4 with decomposition
760 mm @ 158 with decomposition

It's rally worth getting a vacuum source, aspirator and recirculating pump. sparing really needs good filtering of the air to avoid hastening decomposition from stuff in the air.

There's no advantage that I know of to using O2 at any practical pressure, except in removing excess money.

H2O2 of 80% on up gets exciting.

H2O2 Links

franklyn - 27-9-2006 at 21:28

I have collected some useful links researching H2O2 production and availability.
Two related threads in this forum are here _
http://www.sciencemadness.org/talk/viewthread.php?tid=3214#p...
http://www.sciencemadness.org/talk/viewthread.php?tid=2150#p...

It's my conclusion that the price of HTP ( high test peroxide ) even if it is available
at all in the modest amounts needed by experimenters , but more typically even in
30 liter jerry can sizes is excessively costly. Anything above standard 35% strength
incurs additional hazardous handling charges since 50% strength is considered
( what it is ) an oxidizer.
Some practical and enterprising individuals have resorted quite succesfully to
distilling 35% grade to acheive 98-99% pure propellant grade.
http://www.tecaeromex.com/ingles/destilai.html

Good accurate practical information from individuals who handle and work with HTP
http://www.peroxidepropulsion.com/article/3
http://www.gkllc.com/hydrogen_peroxide_tech_data.html

I posted this elsewhere before , it has good overall information
http://www.h2o2.com
http://www.h2o2.com/intro/properties.html

Here is how peroxide is made industrially
http://www.cheresources.com/h2o2.shtml

available grades
http://www.fmcchemicals.com/Default.aspx?tabid=1441
http://www.solvaychemicals.us/services/resourcelibrary/hydro...

useful info on assaying and handling , read the whole thing
http://www.arkema.com/pdf/EN/products/oxygenes/Hydrogen_pero...

How much should you pay ? It's best to see what others are paying
http://uh.edu/researchstores/chemicals_solvents_pricelist.pd...

a source supplier
http://www.dfwx.com/h2o2.html
( I have not purchased them )

another site here posted here _ ( has anyone purchased from them ? )
http://www.sciencemadness.org/talk/viewthread.php?tid=3497&a...
http://chemicals.50webs.com
Listed chemicals
http://www.sciencemadness.org/talk/viewthread.php?action=att...

[Edited on 28-9-2006 by franklyn]

5 - 6-10-2006 at 06:55

Do you know how inexpensive 30% & 40% H2O2 is to buy at a beauty supply store?
Why kill yourself?

Fleaker - 6-10-2006 at 14:24

I've never heard of them selling more than 6% solution at a beauty supply store.

not_important - 6-10-2006 at 20:54

Quote:

Originally posted by 5
Do you know how inexpensive 30% & 40% H2O2 is to buy at a beauty supply store?
Why kill yourself?

Generally that's 6%, 12% if you are lucky. Beauty supply places may take notice of an old, bald guy buying at lot of peroxide. In Canada 30% on up peroxide is going to be tracked and possibly restricted. Expect the US to follow, no matter which of their parties takes control in the upcoming elections.

http://www.sciencemadness.org/talk/viewthread.php?tid=6447

franklyn - 16-4-2007 at 22:33

useful overview and data on H2O2 , see page 9

http://envsolutions.fmc.com/Portals/fao/Content/Docs/FMC%20H...

.

dedalus - 17-4-2007 at 06:42

Another consideration with H2O2 is that metal ions catalyze the autolysis, make sure everything is really clean before starting any concentration procedure.

I used to treat cyanide wastes with peroxide, 50%. I'd add some cupric ions, pump in the peroxide, judiciously. That's important, because when the cyanide went down to the point where free Cu2+ was present, the autolysis reaction would start going like gangbusters and if there was too much peroxide in the mix, the batch would foam over like a stein of beer. Not dangerous, but messy as hell.

Impressive, seeing this happen with a 2000 gallon tank of crap.

DoomsDavid - 8-8-2007 at 07:32

One thing to keep in mind when working with H2O2 in conc. greater than 35 %

the FDA recommends that you refrain from ingesting it or injecting it intravenously.

see .... http://www.h2o2.com/FDA_Press_Release_072706.pdf

Good to know.

vulture - 8-8-2007 at 09:31

That's just to warn against internet quackery.

Anyone with a sane mind knows they shouldn't inject H2O2, even not in low concentration.

Phosphor-ing - 8-8-2007 at 11:19

Injecting 35% H2O2

LMFAO!!

That sounds like Darwin award material for sure!

Ozone - 8-8-2007 at 19:08

Any concentration (1%, even) IV will be instantly broken down by catalase and iron compounds in the blood. This will yield O2 (g) which will (likely) yield clots and death via embolism. Bubbles in the blood stream are bad, mkay!

Greater concentrations should only add to the spectacle, not the final result

.

WTF?

O3

16MillionEyes - 11-8-2007 at 08:02

You can find H2O2 at beauty stores to what they describe as 40 volumes (probably the maximum strength you can get to get those highlights XD) which turns out to be a 12% solution.

Aristocles - 5-11-2007 at 20:33

Quote:

Originally posted by S.C. Wack
I went to the library last Sunday to look up the ozone via H2SO4 electrolysis refs. Not that I have Pt electrodes, just curious. The only peroxide sp. gr. tables that I had were in 10% increments, so I wrote down what was in one of the refs that I stumbled on while doing so. I think that this was at 16C: 20% = 1.0725, 25% = 1.0918, 30% = 1.1122, 35% = 1.1327, 40% = 1.1536, 45% = 1.1749.

I've made small amounts of the Ba and Na peroxide hydrates from the hydroxides and H2O2. Not sure how well these dry out, at least without P2O5 in the vacuum dessicator. But they do precipitate very nicely out of the H2O2 and are easily isolated quickly. I seem to remember reading somewhere that heating without vacuum gives loss of O as well as water, so I haven't tried that.

One of the books that I scanned and uploaded to axehandle, Oxidations in Organic Chemistry, mentions the preparation of anhydrous H2O2 in Et2O from the 30% peroxide if anyone ever needs such a thing.

I make all of my peroxide now, in not small amounts, from drugstore 3%. I hoard it when it is on sale, 3 pints for $1. I used to just let it evaporate because with the stabilizers and all, if you use big clean (buffed to a polish) glass mixing bowls then dust is not a problem. Even 35% can have a bunch of dust on it and not bubble at all. Yields were high. Metal is another story. But then I found that heating below 70C will concentrate to 45% with little loss of O2.

I've tried the freezing yet I use heating. But that's me.

Don't know if this has been mentioned before, but the volume thing is based on how much O can be released from 1 ml of the peroxide; e.g. 1 ml of 3% H2O2 can release 10 ml of O.

Off topic, but the only other thing that happened at the library Sunday, other than the peroxide refs (and being required to present photo ID in addition to my library card!) was accidentally stumbling onto an interesting Na production lecture demonstration from JCE. Looks like Cyrus was onto something when he mentioned using light bulbs in the unconventional Na thread, sort of, but he got no love. I uploaded it to axehandle as na_from_nano3_and _a_light_bulb.pdf. Someone might want to see exactly how much Na a light bulb could produce if left on long enough. I paid too much for mine to not use it, so it's up to someone else.

[Edited on 25-11-2004 by S.C. Wack]

Are you typing that one could get to around 35% by just letting it sit around exposed, and evaporate? Also, if I try heating, by keeping the temp around 70C, I can concentrate to ~50%?

Thanks

[Edited on 5-11-2007 by Aristocles]

S.C. Wack - 6-11-2007 at 03:12

The concentration by evaporation at STP is my own experience. It does take a while. The exact numbers of 45%/70C may be from the literature or I may have accidentally gone too far in the oven one day, I don't remember now. Maybe both.

Obviously I should have chosen cc's instead of ml's as my volume measurement above.

Neil - 9-4-2008 at 17:06

Quote:

Originally posted by Ozone
Any concentration (1%, even) IV will be instantly broken down by catalase and iron compounds in the blood. This will yield O2 (g) which will (likely) yield clots and death via embolism. Bubbles in the blood stream are bad, mkay!

Greater concentrations should only add to the spectacle, not the final result

.

WTF?

O3

Google it... 'oxygen revitalises and refreshes you' or some bs like that... people have been there done that...see here...Scary eh?

Edit: as a side note to Canada's moderation of 35% H2O2, buy it from hydro stores with cash.. they don't keep records of their purchasers for some reason ;o)

[Edited on 9-4-2008 by Neil]

pbmineral - 27-4-2008 at 01:17

Hi everyone,
I had seen in the Handbook that pure H2O2 could be made by extraction of commercial solutions using ethyl ether thjat extracts only pure H2O2, never tried it !
Any suggestions ?

Axt - 26-5-2008 at 06:26

An interesting patent, pitty its jap. It seems its just an acid stabalised H2O2, though it would be interesting to see what concentrations are optained. The reference to it exploding suggests high concentrations.

Concentration of hydrogen peroxide water by heating. Taketa, Kikuo; Watanabe, Satoshi; Sasaki, Shigeru; Naka, Hideo; Okusaki, Junichi. (Sumitomo Chemical Co., Ltd., Japan; Sumika Bunseki Center K. K.). Jpn. Kokai Tokkyo Koho (1998), 5 pp. CODEN: JKXXAF JP 10338508 A 19981222 Heisei. Patent written in Japanese. Application: JP 97-145447 19970603. Priority: . CAN 130:68703 AN 1998:816487 CAPLUS

Patent Family Information

Patent No. Kind Date Application No. Date
JP 10338508 A 19981222 JP 1997-145447 19970603

Priority Application
JP 1997-145447 19970603

Abstract

HCl is added to aq. H2O2, and then the soln. is heated for concn. The HCl addn. prevents explosion of the aq. soln. during the concn.

[Edited on 27-5-2008 by Axt]

Formatik - 27-5-2008 at 20:35

Quote:

Originally posted by pbmineral
Hi everyone,
I had seen in the Handbook that pure H2O2 could be made by extraction of commercial solutions using ethyl ether thjat extracts only pure H2O2, never tried it !
Any suggestions ?

I've done some of these with various concentrations but it was a wasn't worth the ether IMO. First you should know that the mixture is detonable, but even more hazardous is the potential of formation of risky organic peroxides and lastly you have to use a very large amount of ether to extract any significant amount

MagicJigPipe - 27-5-2008 at 21:31

Quote:

Google it... 'oxygen revitalises and refreshes you' or some bs like that... people have been there done that...see here...Scary eh?

Read up on the details of this story. IMO, it was virtually impossible for her death to have been caused by that little H2O2. 25mL of O2 killed her 4 days later? Bullshit.

I've been thinking about the barium peroxide method for producing H2O2. How is barium peroxide obtained?

not_important - 27-5-2008 at 21:49

Quote:

Originally posted by MagicJigPipe
...
I've been thinking about the barium peroxide method for producing H2O2. How is barium peroxide obtained?

Basically by heating barium oxide in CO2 (and SOx NOx) free air. Usually done under a couple of atmospheres of air pressure at 500 to 600 C. An old process for extracting oxygen from the air started with this, then while keeping the temperature the same pumping off the air and then the released O2; repeat until BaO becomes too unreactive.

The BaO is made by heating a mixture of BaCO3 and carbon, made into a paste with oil or tar, to yellow to white heat. The plain carbonate does not decompose readily until much higher temperatures, the carbon causes a decomposition to carbon monoxide and barium oxide at a lower temperature.

lets see now, here's one old reference, there are plenty of others from this time and earlier.

http://books.google.com/books?id=MAA5AAAAIAAJ&pg=PA640&a...

VestriDeus - 15-11-2009 at 13:18

Has anyone tried this:

http://www.instructables.com/id/Distill-Hydrogen-Peroxide/

It says to add iodine-free table salt to low conc. H2O2, and that the stuff should separate into two layers, salt water and hydrogen peroxide.

User - 16-11-2009 at 04:00

I dont want to reject the possibility directly, anyway that guy that wrote the stuff does not really know what he's talking about.
"Distill Hydrogen Peroxide"
Distilling?, what is he distilling?

It could be that NaCl is fully insoluble in hydrogenperoxide, in this case it could be possible to force the H2O2 out by saturating the H2O.

Can anyone support this ?

Formatik - 16-11-2009 at 15:14

Way to contaminate with metallic cations. Sodium chloride is a catalyst for H2O2 decomposition, not as strong as Pt, Ag, Os, MnO2, etc. but in the same order as CuO, Mn(NO3)2, HgO, AgO, FeO, ZnSO4, Na2CO3, CaCl2, BaCl2, etc. Nothing there even hints that a more conc. peroxide results. It looks like a joke.

Sedit - 16-11-2009 at 17:59

This more then likely has been suggested already but the idea has been floating in my head for about a week and with all this talk of H2O2 concentration going around how would this work out?

Placing an open bottle of H2O2 into a dessicator bag full of MgSO4 and sealed up in a dark place. It will eliminate the worry of organic dust falling in while still allowing it to evaporate the water from the solution.

I suspect near 100% H2O2 could in theory be formed this way but perhaps some form of equilibrium will setup with water absorbant properties of H2O2 that I do not know about.

User - 16-11-2009 at 19:54

I can see your point.
Often i wonder why such hard ways of doing stuff is considered.
Dessicating substances is such an old and plain simple way.
The same thing can be done with HNO3 if the absorbing properties are high enough.

[Edited on 17-11-2009 by User]

Formatik - 17-11-2009 at 21:58

Quote: Originally posted by Sedit

This more then likely has been suggested already but the idea has been floating in my head for about a week and with all this talk of H2O2 concentration going around how would this work out?

Placing an open bottle of H2O2 into a dessicator bag full of MgSO4 and sealed up in a dark place. It will eliminate the worry of organic dust falling in while still allowing it to evaporate the water from the solution.

The threat of organics (like cellulosics), is often due to present trace metal catalysts. So, I wouldn't dry H2O2 with metallic salts like MgSO4 because then of airborne particulates that would end up contaminating it. Sterile environment is crucial for high strength peroxide. P2O5 or H2SO4 are good choices. Regular dessication works for higher strength, but takes a long time. Vacuum dessication is said to work even faster. There are other conc. threads that talk about this in detail. I also suggest to see what Mellor has to say about concentration.

Sedit - 18-11-2009 at 06:31

Your right Formatik although it can be solved with a little glass wool in the opening though. I hate the idea of drying stuff with H2SO4 for some reason. I will look into Mellor and see what kind of data he gives although its not to important to me since I can get 35% with ease and thats more then enough for most things for me. Very few synthesis call for 100% H2O2 so the rest is just bulk.

C6(NO2)5CH2CH(CH3)N(NO2)2 - 12-2-2019 at 14:48

I was going to concentrate some hydrogen peroxide by slow evaporation, but I noticed that the permissable exposure limit for the vapor is 1ppm, according to wikipedia. I don't want to try evaporating it outside, because there is rain, dust, animals, wind, and so many other factors which make it hard to leave an open tray of reagent. I already tried putting some in a freezer, but the liquid fraction was absorbed and 'lost' in a mass of water ice (imagine a spoon of water in a cup of sand). If you evaporate a solution of peroxide inside, is the vapor really something to worry about?

I am surprised that it's considered safe to dab disinfectant with 3% liquid hydrogen peroxide on an open cut, but that a milliliter of that same solution (1mmol H2O2) evaporated in a room with a volume of 20,000 liters is considered unsafe.

And no, I don't have a fume hood or vacuum distillation equipment, so those options are out of the question for now.

zed - 17-2-2019 at 14:59

What concentration do you need?

morganbw - 18-2-2019 at 10:49

Quote: Originally posted by C6(NO2)5CH2CH(CH3)N(NO2)2

I was going to concentrate some hydrogen peroxide by slow evaporation, but I noticed that the permissable exposure limit for the vapor is 1ppm, according to wikipedia. I don't want to try evaporating it outside, because there is rain, dust, animals, wind, and so many other factors which make it hard to leave an open tray of reagent. I already tried putting some in a freezer, but the liquid fraction was absorbed and 'lost' in a mass of water ice (imagine a spoon of water in a cup of sand). If you evaporate a solution of peroxide inside, is the vapor really something to worry about?

I am surprised that it's considered safe to dab disinfectant with 3% liquid hydrogen peroxide on an open cut, but that a milliliter of that same solution (1mmol H2O2) evaporated in a room with a volume of 20,000 liters is considered unsafe.

And no, I don't have a fume hood or vacuum distillation equipment, so those options are out of the question for now.

Perhaps another hobby.
Can you point to death by too much hydrogen peroxide in the air?
Not on my worry list.

happyfooddance - 18-2-2019 at 11:00

Quote: Originally posted by C6(NO2)5CH2CH(CH3)N(NO2)2

I already tried putting some in a freezer, but the liquid fraction was absorbed and 'lost' in a mass of water ice (imagine a spoon of water in a cup of sand).

Did you try to filter this mass while still in the freezer perhaps?
You may be able collect a useable amount of product by letting it sit filtering overnight.

I mostly agree with morganbw on this one though.

C6(NO2)5CH2CH(CH3)N(NO2)2 - 19-2-2019 at 14:45

Morganbw, it's not that I'm so worried about chemical exposure. I would like to think I could safely handle any vapor while inhaling less than 1 ppm. But to do that, I'd use a combination of extra safety equipment (respirator cartridges?), good ventilation, and precautions to limit how much vapor was emitted (e.g. I'd put it in a jar, in a sealed bag of dehydrated epsom salt or silica gel outside). But, if a material is not dangerous to inhale, then I'm not going to waste my time money and equipment trying to keep the vapors out of my house. What led me to look up those exposure limits was an idea I had to concentrate hydrogen peroxide conveniently. I thought about pouring it onto a plate in a parked car during summer, it will heat up to 60C more or less and some of the water would evaporate, and then I would pour the (now concentrated) H2O2 in a bottle and roll down the windows to get rid of the humidity while driving home. The only question was I was unsure if it was okay to breathe air that had that much hydrogen peroxide in it. Would it be okay to get in a car with 1000 ppm H2O2? would it poison me? So, I looked it up online: the answers are NO!, and maybe.

I'm still not sure why OSHA set the limit so low. For carbon tetrachloride and hydrogen cyanide the set it at 10 ppm, for nitrogen dioxide 5ppm, for nitric acid 2 ppm, for ethylene oxide and elemental chlorine 1ppm, for phosphine 0.3ppm, and for chlorine dioxide .1 ppm. Bear in mind that these values are all for all-day, occupational type exposure, if you have something with low acute toxicity like carbon tetrachloride you can have a bit more during a short term experiment. But hydrogen peroxide seems like a safe, mundane chemical compared to all of those, so I don't know why they are so worried about it.

I'm trying to concentrate a 3% hydrogen peroxide disinfectant, to a concentration of preferably over 15%, although 30 would be ideal. I don't need rocket fuel here. Last night, I filled a 118ml plastic bottle half full with 3% solution and let it freeze on its side with the capped end angled slightly up. It froze into a solid piece, and in the morning I turned it cap down and squeezed it to make some cracks in the ice. While I did that, several milliliters of liquid ran out of the ice and gathered in the cap. The temp was -6C, and that fluid resisted freezing, so I think it is at least 10% according to https://en.wikipedia.org/wiki/Hydrogen_peroxide#/media/File

hase_diagram_hydrogen_peroxide_water.svg

The bottle is still draining , and the temperature is falling again, so I will see what concentration and amount is yielded. To check concentration I will try to react a bit with MnO2 or yeast or something and see how much oxygen I get. I am kind of optimistic this time: the key I think is to not freeze it to as low of a temperature (although you will get lower concentration that way) and more importantly, freeze it slowly so you don't get as small of crystals to act as a sponge. If this fails I may try to filter out the ice as it freezes-that should get a good yield, and failing that, I will find a way to evaporate it. I won't quite treat it like liquid chlorine, but I won't be setting a plate of it in my bedroom, either

C6(NO2)5CH2CH(CH3)N(NO2)2 - 26-2-2019 at 14:37

The liquid fraction was about 15ml, which tested at 30 volumes of oxygen using yeast, or around 10%. I should have got something like 18ml of 10% from 60ml of 3%, so about 3ml, or one ml per 15ml of water ice, was retained. That could make it hard for higher concentrations, since for 30% you will only have about 1ml of product per 10ml ice. That means the majority of it could be absorbed in the ice. Next thing to try will be crushing it better, and maybe exposing it to centrifugal force briefly.

zed - 26-2-2019 at 16:47

Evaporation is OK.

Years ago, someone here posted a table.

H2O2 concentration may be easily determined by specific gravity.

Elaborate chemical tests aren't required. Just use a hydrometer.

CharlieA - 26-2-2019 at 17:56

Are there small hydrometer/hydrometer jars? (Just curious because right now I'm too lazy and watching a hockey game to get up and look in a catalog.) If you have a balance that will weigh to 2 decimal places, and a 10.0 mL pipette or volumetric flask, you can measure density to 3 significant figures, which I would think would give a good approximation of the density. How does the yeast method work?

wg48temp9 - 27-2-2019 at 12:39

Quote: Originally posted by C6(NO2)5CH2CH(CH3)N(NO2)2

I filled a 118ml plastic bottle half full with 3% solution and let it freeze on its side with the capped end angled slightly up. It froze into a solid piece, and in the morning I turned it cap down and squeezed it to make some cracks in the ice. While I did that, several milliliters of liquid ran out of the ice and gathered in the cap. The temp was -6C, and that fluid resisted freezing, so I think it is at least 10% according to https://en.wikipedia.org/wiki/Hydrogen_peroxide#/media/File

hase_diagram_hydrogen_peroxide_water.svg

If I have the above correct all I have to do is freeze my H2O2 water solution to form a mixture of solid and liquid, assuming the original strength of the H2O2 solution is less than about 50% and the mixture has a achieved equilibrium , the liquid is a higher strength than the strength of the original solution.

So for example if I freeze the dilute H2O2 solution in a freeze to say -25C (thermostat turned full on) then the liquid remaining will have strength of 30%. Obviously I don't know how much H2O2 will be trapped in the solid but even if its 50% of the total H2O2 its not destroyed so it sounds like a very practical method to obtain 30% H2O2, assuming you can get the freezer down to -25C. I will have to give it a try with my 12% solution preferably with stirring to form a slush I can filter off the liquid easily.

Below is a more detailed phase diagram. It confirms that the solid is water ice above about -50C. Its also interesting that the maximum strength achievable with this method is about 60% and that H2O2 forms an adduct /crystal structure between the H2O2 and water.

hydrogen-peroxide-Solid---Liquid-Phase-Diagra.gif - 13kB

Sorry I have lost the reference to the file