209
Harmless
Posts: 20
Registered: 23-1-2007
Member Is Offline
Mood: No Mood
|
|
Hydrogen peroxide
Being that in high levels of concentration, this sure as hell is an energetic material, thought it would be best to post here. I have latly beeing
looking a lot at rocket belts and other thrust propultion ideas. I know you can concentrate H202 from 3% to about 30% without it decomposing, but
thats not good enough. I need concentrations up to 85-90% concentrations, any ideas on how to concentrate it this high? Obviously I would need massive
amounts of H202, but I think I know were I can get it. Any ideas?
|
|
ssdd
Hazard to Others
Posts: 211
Registered: 13-4-2007
Location: Central Canada
Member Is Offline
Mood: Hypergolic
|
|
I would think somewhere there would be a thread on this...
But I did some searching and didn't seem to find much.
But I also would be interested in this because I am sick of 3% and my experiments not working because of it.
If someone has anything I'll keep looking...
Would it be simpler to buy 30% and try and concentrate that?
-ssdd
|
|
hashashan
Hazard to Others
Posts: 255
Registered: 10-10-2006
Member Is Offline
Mood: No Mood
|
|
you should distill it. the procedure is quite risky. and of course it will be simpler to buy 30%. you have 10 times more H2O2 there then in the 3%
|
|
roamingnome
Hazard to Others
Posts: 363
Registered: 9-9-2006
Member Is Offline
Mood: No Mood
|
|
phase diagrams
are your friend
http://www.h2o2.com/intro/properties/physical.html
try dry ice first...
|
|
gregxy
Hazard to Others
Posts: 421
Registered: 26-5-2006
Member Is Offline
Mood: No Mood
|
|
There is a long thread on this but I didnt see that anyone made it work for 3%. I tried the freezing method. Supposedly the water freezes at a higher
temp and you pull out the block of water ice leaving more highly concenterated peroxide. However for me it just froze solid. I think that all of the
H2O2 ended up trapped in small cracks in the ice.
For making HMTD and the like there is a company on EBAY that sells little 30ml bottles of 30%. More that enough to blow off all of your fingers.
For a rocket you are going to need kilos of it so you would need to find a source to sell you the concentrated stuff. People make rockets that run on
pure peroxide but that seems like a waste of oxygen. Better to figure out how to use peroxide and alcohol. Or else use N2O and salami like the
Mythbusters.
There is this cool video of a guy that made a "personal jet" with a 6 foot wing span. It is powered by 4 big model airplane jet engines. It could not
take off from the ground but he would jump out of an airplane and fly around for about 5 minutes before he burned up all his gas, then he opened a
parachute and floated down.
|
|
mbrown3391
Hazard to Others
Posts: 133
Registered: 2-9-2006
Member Is Offline
Mood: No Mood
|
|
try a local beauty supply store. I can get large bottles (half liter) of 40% h2o2 for 4 bucks!
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
Quote: | Originally posted by mbrown3391
try a local beauty supply store. I can get large bottles (half liter) of 40% h2o2 for 4 bucks! |
Forty percent or forty volume? All the beauty supply peroxide I've seen isn't above 12%, most comes labeled as 10, 20, 30, 40, or 50 volume.
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
When using the freezing method you must lower the temperature very slowly, in order to get the ice to form as a solid block.
Alternatively you can freeze the solution, drain off and collect any liquid, crush the ice, and drain off and collect the liquid from it - letting the
ice slightly melt.
If you check the reference roamingnome posted, you'll see that water freezes out down to about -50 C, and 50% concentration. The freezing point as
degrees C below zero is roughly the percentage of H2O2, in a handwaving sort of fashion.
You don't distill the peroxide, you distill or evaporate off the water. Use reduced pressure, a water bath, and don't heat about 50 or 60 C.
|
|
hashashan
Hazard to Others
Posts: 255
Registered: 10-10-2006
Member Is Offline
Mood: No Mood
|
|
will the freezing method work for 3%?
i have this thought the the 3% stuff is a byproduct of 90% production via freezing method. i mean the ice collected that contins some peroxide .. 3%
maybe>?
|
|
The_Davster
A pnictogen
Posts: 2861
Registered: 18-11-2003
Member Is Offline
Mood: .
|
|
As not_important mentioned, I have read several papers in which 30% was concentrated to 80-90% using a rotovap and reduced pressure.
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
Quote: | Originally posted by hashashan
will the freezing method work for 3%?
i have this thought the the 3% stuff is a byproduct of 90% production via freezing method. i mean the ice collected that contins some peroxide .. 3%
maybe>? |
Freezing is for people who don't have the equipment to do the evaporation method, or who think that "warming" means any temperature that doesn't melt
the flask. I doubt that it is used industrially.
And as I said and the phase diagrams show, you can't get much above a concentration of 50% peroxide by freezing out water. At concentrations between
50 and 60 percent a mixture of H2O2 and H2O freezes out, at still higher concentrations H2O2 itself freezes out. So the 'ice' from really strong
peroxide is nearly 100% H2O2, and you can't concentrate a solution in water above about 60% - the eutectic point.
|
|
franklyn
International Hazard
Posts: 3026
Registered: 30-5-2006
Location: Da Big Apple
Member Is Offline
Mood: No Mood
|
|
How many more times
http://www.sciencemadness.org/talk/viewthread.php?tid=1325&a...
|
|
vulture
Forum Gatekeeper
Posts: 3330
Registered: 25-5-2002
Location: France
Member Is Offline
Mood: No Mood
|
|
And that closes this thread...
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
|
|