Introduction: Self-Igniting High Temperature Reaction

Picture of Self-Igniting High Temperature Reaction

This is a pretty basic but nonetheless awesome demo. Glycerine (Glycerol, 1,2,3-propantriol) is mixed with potassium permanganate (KMnO4), and within about 30 seconds, the pile starts to smoke, then burns with a very hot lavender colored flame.

-This is a hot-burning reduction/oxidation reaction. It doesn't spark as a thermite reaction would, but still, don't do something dumb like put it on a wood table.
-KMnO4 likes to stain stuff. If it comes into contact with moisture it will form a purple solution that will render anything purple permanently (your skin will turn brown but that comes off in a few days)
-Non-science types don't understand chemistry. People fear things they don't understand. In other words, many ignorant people think chemistry is evil/terrorism/just plain bad, so don't do this around people if you know they are going to flip.
-I am not liable in the event of fire, explosion, injury, disability, death, act of God/Goddess, rabid squirrel attacks, subpoena, lawsuits, or any other dumb situation you might manage to get yourself in. Use your brain and use basic common sense

Warning: Science content!
If you want to figure out how to get a stoichiometric reaction (basically molecule for molecule reaction, most efficient burn) you can start with this equation:

14 KMnO4 + 4 C3H5(OH)3 --> 7 K2CO3 + 7 Mn2O3 + 5 CO2 + 16 H2O + HEAT

That calculates out to be 6 g KMnO4 for 1 g glycerin. Honestly, there isn't any point to weighting it out, it works just as well mixing approximate amounts.

Step 1: Prepare Your Materials

Picture of Prepare Your Materials

You will definitely need:
-Potassium permanganate - this is sold at small hardware stores like Ace as filter cleaner - $5
-Glycerine - sold at RiteAid - $3

-Additionally, you can use antifreeze or windshield washer fluid if it contains the ingredient ethylene glycol. Ethylene glycol is C2H4(OH)2 whereas glycerin is C3H5(OH)3. It's the multiple alcohol group that makes it work. Also, make sure it is of the highest concentration possible. Water typically does not help with fire-making processes.

Stuff that's a good idea to have
-Burn plate - I used a granite tile I got as a sample from a countertop store
-Goggles - this isn't a super dangerous reaction, use your own discretion
-Sand - if for some reason you have to put it out - water will make a HUGE mess because it forms KMnO4 solution which stains anything and everything purple

Step 2: Prepare the KMnO4

Picture of Prepare the KMnO4

Find a nice suitable place to be burning things. This should be away from flammable things, tall grass, small children etc.

Make a small pile of KMnO4. The size isn't critical, obviously the more permanganate you use the more glycerin you will need.

Furrow out a "bird's nest" in the middle of the pile. If you've ever made bread before (rustic method), it's the same concept.

Step 3: Add Glycerin

Picture of Add Glycerin

Pour the glycerin into the furrow. The ratio between KMnO4 and glycerin is very forgiving, but you should have about 1.5:1 KMnO4:glycerin, volumetrically.

Depending on the ambient temperature, the reaction might not self initiate at this point. Give it some time. If it doesn't start smoking after 45 seconds, either mix it with a stick, or drop some HCl onto it. The reaction is slow to start up, you will see smoke before the fire with enough time for you to react and get your hands away.

The chemistry here is called a hypergolic reaction. Compounds that are reactive enough to begin a reaction just by being in contact with each other are said to be hypergolic. Other examples include hydrazine and nitrous oxide, and sodium and water. The rate of reaction depends on the fuel used, the temperature, and water content. Water obviously retards the reaction.

Warning: Science Content!
Ethylene glycol: It has the smallest molecular weight, and thus the most active; concentrated or pure it will react very fast

Glycerin: Slightly less reactive than ethylene glycol, the reaction could be hypergolic on a hot day and not on a cold one.

Propylene glycol: The least reactive due to high molecular weight and lower reactivity (less function groups). Anything but pure might not react at all.

Alcohols: These won't work at all, they aren't reactive enough to start the reaction by itself.

Anecdote time! I had a Dixie cup full of the stuff in my hand (this was at the time when I had to set it off with HCl because it was colder) but that day was very hot. I saw it starting to smoke in my hand and I threw it, only to have it burst into flames mid-air.

Step 4: Fire!

Picture of Fire!
After a short time, the reaction will start to smoke. This is your cue to step back a little. It will burst into flames and depending on how close to stoichiometric you got, it will burn something like a road flare or rocket engine.

Uses: Aside from a really neat chemistry demo, the reaction burns hot enough to initiate other reactions with exorbitant activation energies, namely, thermite. I don't have any thermite to play with, so I haven't tested it myself, but I've seen it work. The KMnO4/glycerin doesn't spark and cause excessive destruction around it, but if you use it to initiate a thermite reaction, the thermite WILL do what it's good at: melting and setting fire to everything around it, so take this into account when picking a location.


-Aj- (author)2008-04-20

best way to light thermite is to use 3 sparklers at the same time.

qualia (author)-Aj-2008-06-13

its the most efficient/easy/cheap/ foolproof way. its fairly difficult to light Mg ribbon in mildly windy conditions, whereas sparklers will burn even in mild rain. and sparklers can be inserted directly into a pile of thermite, without being extinguished. if you want a better way than either mg ribbon or thermite, use very thin-walled Mg tubing, filled with potassium nitrate. at the tip of the device, pack slow burning gunpowder for easy ignition.

DeusXMachina (author)qualia2008-06-13

Where the HECK do you get Mg Tubing?

ilpug (author)DeusXMachina2012-02-01

my reaction exactly!

puffyfluff (author)2008-10-06

I'm getting wild ideas...

Berkin (author)puffyfluff2008-10-29

You could make this like a grenade, so when you pull the pin it mixes the two chemicals and eventually explodes.

puffyfluff (author)Berkin2008-11-02

Hey, that's a great idea!

ilpug (author)puffyfluff2012-02-01

It really won't explode, just catch on fire. I suppose you could make it into some kind of fire paste like napalm if you could slow down the ignition time...

ilpug (author)2012-02-01

We did this in chemistry class, it works great!

DeusXMachina (author)2007-07-08

@ pyromaniac3-2-1 - unfortunately as oxidizers go, KMnO4 is no where near as reactive as nitrates, chlorates, or perchlorates. I've tried making firecrackers using fine charcoal and permanganate but it did bubkus. And I found this out through my awesome 10th grade chem teacher. Imagine the Roaming Gnome or Santa Claus in a lab coat. At the end of the year he'd shoot spudguns out the window. @Andrew - Wikipedia says that early flashpowder formulations used permanganate, but I have no clue what other ingredients were used with. I would think that permanganate reacts too slow, but maybe if you had aluminum and KMnO4 in a 1:3 ratio, with a dash of KClO3 for sensitivity, I think that would work. You would need very fine aluminum and you would probably have to run the permanganate through a ball mill first.

ablock (author)DeusXMachina2011-01-08

You had Mr. Albee for Chemistry too?

sulpher and fine mesh dark german aluminum powder is what your missing.

YoungPyro19 (author)2010-05-22

Very nice instructable.

history323 (author)2009-10-30

hey great 'ible
 do you know if this could ignite thermite?

QwertyuioLP (author)2009-09-02

can this burn through wood? metal? plastic?

DeusXMachina (author)QwertyuioLP2009-09-04

It can burn through wood and plastic pretty easily, although not very much of it. It doesn't quite have the penetrating power of Thermite.

ramses (author)2008-02-24

DeusXMachina- where did you get the KMnO4, I found some at tractor supply $24 for 5 lbs, and at ace $12 for 1.5lbs. where did you find it so cheap?

DeusXMachina (author)ramses2008-02-25

Ace. I dunno why you got charged so much or why I got charged so little.

bylerfamily (author)DeusXMachina2009-07-05

Yours was probably on sale.

Pumpkin$ (author)DeusXMachina2008-04-12

that's what.... *cackling*

crapflinger (author)2007-06-28

hehe i like how in the second video you can see an ant (or some other bug) running for it's life

bylerfamily (author)crapflinger2009-07-05

Yeah,that is funny.

lol thats what i was thinkin

funny as hell

bespenschied (author)2007-12-16

I remember something from my 8th Grade science class that had to do with catalysts. I think we were making KMnO4 and the catalysts was a copper bb. Mine didn't change very quickly until some moron bumped into me and dumped it all over my light colored shirt and stained it purple. My teacher mixed something up in a beaker that took it right out. I forgot what it was he mixed up in that beaker but he said it was a miracle cleaner and would clean almost every stain. It was pretty amazing stuff.

bylerfamily (author)bespenschied2009-07-01

You mix 30% hydrogen peroxide,40% vinegar and 30% water to clean off permanganate stains.

hahaha probably a mild bleach. (theres more than one type of bleach, you know)

Anything that will break the oxygen bonds will work in that case.

DeusXMachina (author)2009-04-12

Probably... Try it.

Evilblaze (author)2009-03-16

Hehe, nice:-) I did this with ethylene glycol, that was also a good fun. Have you tried self igniting mix with ammonium-permanganate? NH4MnO4 is a much more stronger oxidizer than KMnO4, it is a class 5 oxidiser (like +80% H2O2). I will test it soon.

lobo_pal (author)2009-01-21

KMnO4 can be used as a prank if you put it in a pool, the water will turn purple, but it will dye the pool, so don't do it to your's.

Bright Shadow (author)lobo_pal2009-02-15

unless you have a purple pool to start with.

lobo_pal (author)Bright Shadow2009-02-15

Yeah, also, I wouldn't recommend swimming in it. Great to use on enemies.

rerat (author)2007-06-28

Is this the "mix 'blur' with 'blur'" reaction Mythbusters used to light their thermite?

MadMechanicMike (author)rerat2007-07-09

no, you need some type of magnesium compound to ignite thermite. it takes ALOT of heat and the easiest source is made with magnesium. google is a magical thing that will tell you exactly what you want to know.

under the right conditions(which most people cant replicate), thermite is easily ignited with a common Bic lighter :)

5George5 (author)paulmasoner2008-04-29

thermite does need high temperatures to initiate the reaction. it is still very easy to do with a few sparklers (like aj says) which are made out of some mixture of magnesium. a lighter will not start thermite.

mettaurlover (author)5George52009-01-04

notice that he said under the right conditions and which most people can't replicate as well.

Xarkumetru (author)rerat2007-08-30

No, what they where "blurring" out was the ingredients to thermite(Aluminum powder 400 mesh & Iron oxide Rust), they lit it with a strip of Magnesium Ribbon. all EXTREMLY easy to obtain, and they couldn't telivise that for obvious reasons.

Which obvious reasons are those? Anyone interested has to only google the word thermite to find the ingredients. It's done as a demo in some schools even, an exciting example of a Displacement / Redox reaction.

it's a liability thing, i think.

America: Where everybody sues everyone for everything

Right, but they can't be the ones to tell you that for "Legal" reasons...

smokehill (author)Xarkumetru2007-10-28

Absolutely right. Look what happened to the publishers of "Hit Man," when some bozo used some of their hints (mostly simple common sense & ideas available in a million other places) in a killing. The sleazy lawyers sued the publishers & won a 7-figure windfall. You can't be too careful when lawyers & an ignorant jury are likely to be involved.

agreed. an ignorant and/or PMS judge is usually the problem.

Charles IV (author)Xarkumetru2008-05-02

They used thermite and told that one part was aluminum on the show "Breaking Bad".

triggernum5 (author)Xarkumetru2008-03-22

Actually this is what they blurred.. They didn't use Mg Ribbon..

trebuchet03 (author)rerat2007-06-28

I believe so ;)

rip333 (author)2008-12-03

As to the people who say you don't need high temps to light thermite, you have to realize the sparklers are any were between 2000 and 4000 degrees Fahrenheit, usually around 3000.

raykholo (author)2008-09-02

so to make it more like a flare can u put the powder at the bottom of pvc pipe (thin) , plug up the end, and find a way to "automatically" combine it with the liquid? and the sparklers work good with small amounts of aluminum (my personal experience says that they make lots of smoke if u put them into an empty can with the top cut off)

About This Instructable




Bio: My goal in life is to be a chemistry professor, because a) I've had lots of awesome influential teachers b)Bill Nye kicks ass ... More »
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