Salting out is a process that can be used to dehydrate Isopropyl alcohol, i.e., separate it from water in an azeotropic solution. Dehydrated Isopropyl is useful as a fuel by itself and in helping to determine the right amount of catalyst to add when making bio-diesel fuel.

Removing water also increases the Isopropyl alcohol's ability to:

> melt ice off your frozen windshield
> dissolve water in gasoline
> burn cleaner when used as a standalone fuel
> provide your pet with an invigorating rub after his next bath, which is curiously strong enough (dry enough) to dislodge stubborn ticks and fleas
> serve as a powerful pet or human wound antiseptic
> wash out those wax filled ears
> save you big $$$ (dough, ka-ching, moola, etc.) think money*

(*99.9% Isopropyl Iso-Heet at auto stores runs around 18.25 cents per ounce. 99.9% Isopropyl made from salting out 50%-91% generic retail brand Isopropyl runs around 6.73 cents per ounce. That is a savings of over 63%. If you use it to dry your gasoline then be sure to remove the residual salt using the addendum method.)

What you need:

- bottle of 50% to 70% Isopropyl alcohol
- a wide mouth glass jar and lid, or other leak and Isopropyl proof container
- a pound of non-iodized table salt
- a turkey baster with a reduced size nozzle
- an empty bottle equal in size to the bottle of Isopropyl alcohol.
 
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botronics says: Dec 16, 2012. 5:32 PM
Can this work with Vodka? I need pure ethanol for making a Fitzroy Storm Glass. Which is a mixture of camphor, ammonium chloride, potassium nitrate, water and ethanol.
AlwaysChoseCharmander says: Aug 14, 2012. 9:37 PM
Just tried this, stove works much better thanks! I put the Isopropyl in the same container. Crossed out the fifty percent and wrote 'much higher'.
ironLes4 says: Aug 5, 2012. 7:08 PM
can you use a salt subtitute
h0meIandsecurity says: Nov 7, 2010. 9:30 AM
hahahaha, funny
emergencydpt.com says: Oct 29, 2008. 5:47 PM
You could put the salt on your margarita for a scientific buz...or was the alcohol in the water?
versusterminus19 in reply to emergencydpt.comJan 9, 2010. 5:54 PM
Isopropyl alcohol is definitely not something you want to drink. Not all alcohols get you drunk, as far as I know ethanol is the only one that does it without some pretty nasty side effects (although hangovers aren't too fun ;))
nathanielg in reply to versusterminus19Aug 23, 2010. 2:14 PM
I have read that if you drink isopropyl alcohol it can cause blindness or even death.
binnie in reply to nathanielgOct 16, 2010. 7:21 AM
most alcohols actually cause blindness, and ethanol is really the only alcohol thats safe to drink (not that its that safe eh ;D ) most other alcohols cause blindness in really small quantities, and theyr all very lethal poisons.
Qcks says: Feb 7, 2010. 11:37 AM
Just gonna add...
If you're having issues with salt residue in your isopropyl, you can limit the solubility of the Sodium Chloride by doping the isopropyl with sodium hydroxide prior to salting it.

This has the advantage of having a solvation effect with the salt and the base (Sodium Hydroxide competes with Sodium Chloride for solvation with the water because both have a sodium cation). Any residual hydroxide compound should burn clean.

The biggest downside is that you might begin to push your isopropyl to undergo a synthesis reaction, but due to it's shape that's not very likely (that is to say, it's stearically hindered, and thus, unlikely to undergo any synthesis reactions).
lpkid1057 in reply to QcksJul 5, 2010. 1:46 PM
Love the pedantic organic chemistry guy here.
junits15 says: Sep 3, 2009. 2:29 PM
what happens if I use iodized salt?
Mikie-z in reply to junits15May 20, 2010. 5:41 PM
Most likely reason why people say to not use iodized salt is because it has iodine which can either A) make I2 which is non polar and may mix with alcohol as apposed to the water or B) could make a iodo-*suffix* compound.
Only speculation from a hobby chemist though.
dammat says: Nov 16, 2008. 8:30 AM
Wouldnt silica gel work to remove the water? I found an experiment online that somehow used silica in a distillation column to remove the water. The water vapor is easil absorbed by the silica gel. Silica will retain up to 40% of its weight in water. Seems like a good idea to me. Otherwise I would research how its manufactured on a larger scale.
Broom in reply to dammatJun 26, 2009. 3:26 PM
Seems to me the problems are: 1. You'd need 2.5x the weight of water in silica gel - that's a fair amount, and salt is easier to come by. 2. Is silica gel soluble in isopropyl alcohol? If so, it wouldn't work at all. 3. Does silica gel absorb isopropyl alcohol? If so, it wouldn't work at all. Seems to me table salt is the better solution (no pun intended).
Aerospaced in reply to BroomOct 20, 2009. 6:00 AM
You could use lime to do the same thing. When I was growing up, my dad taught me this trick.
Take some ordinary dry wall and bake it in a toaster oven OUTSIDE. The paper on the outside may burn off. The lime left behind will be completely dried out. Take the lime and crush it into as fine of a powder as you can. Add it to your alcohol and mix thoroughly. Let it set over night and either re distill or  use a sepratory funnel to get the end product.
 We had a farm that had a large above ground gas tank for refilling our tractor. It would accumulate water and had to be dried out. 
patmccock says: Oct 18, 2009. 11:14 PM
i used 91% isoproply alcohol and it wont work why is that?
DrCoolSanta in reply to patmccockOct 20, 2009. 4:47 AM
Thats what the product is suppose to be. If you use more dilute alcohol this will work. Just add some water to this and see :P
spark master says: Oct 6, 2009. 8:44 PM
Methyl and isopropal can be absorbed through the skin, if you use it a lot it can have bad effects on you, rub downs with alks should only be with ethyl. They tell you now never rub your kid down with it . When I was a kid everyone knew to use rubbing alks for fevers. No Mas muchacha
spark master says: Oct 6, 2009. 8:37 PM
isopropal is lousey for alcohol stoves, methyl is great , but ethyl is best (more btu's. Since we can drink it it is heavily taxed. Denatured alks are mixtures and can have ethyle and methyl and other crap. The other crap will soot pans and in some cases stinks like heck. Go to the site for S-L-X denatured alcohol, the stuff varies. GO to Minibull Designs.com and look for Tinny's fuel comparasons, it explains much. This is a great article/instructable. You could if you had equipment, or really cold cold streak, do cryogenic distillation. Put a few gallons in a drum freeze it to -20 for say a few days then let it 'warm to -10 few hours, then refreeze to -20, do this a few cycles and ice crytals will form on out sideof alcohol column. Well it does with hard apple cider. But you need those frigid upstate NY death by cold winters. Farmers could leave casks of hard cider freeze then pop a hole in the center and drain off the liquer. Not worth the effort though. Buy heet or Air Brake Antifreeze, pure methyl spirits, 98%. If you are lucky enough you may find a speed shop that sells it by the gallon out of a drum, (bring clean jug/can) 4-8 bucks a gallon. Sadly I can't find one by me. I enjoyed this piece I will re read later on in the week.
J@50n says: Sep 27, 2009. 4:02 PM
just wondering, is this the same as denatured alcohol?
Pyrotechnic-Robot says: Aug 12, 2009. 10:15 AM
slurp slurp bubble bubble gurgle gurgle haha very nice.
Berkin says: Jun 9, 2009. 7:18 PM
What happens if you use iodized salt?
lilpepsikraker in reply to BerkinAug 7, 2009. 9:26 PM
KA-BOOOOOOOOOOOOOOOOOOOM!
Berkin in reply to lilpepsikrakerAug 12, 2009. 8:34 AM
I doubt that.
Weissensteinburg says: Mar 9, 2008. 8:02 PM
Why is it 91% alcohol, and not 100?
omnibot in reply to WeissensteinburgJun 29, 2009. 2:37 AM
Found it!
The reason why alcohol is never 100% is *drum roll* is that hydrogen bonding causes pure ethanol to be hygroscopic to the extent that it readily absorbs water from the air.
Mixtures of ethanol and water form an azeotrope at approx. 89 mole-% ethanol and 11 mole-% water or a mixture of about 96 volume percent ethanol and 4 % water at normal pressure and T=351 K. This azeotropic composition is strongly temperature- and pressure-dependent and vanishes at temperatures below 303 K. Wikipedia
omnibot in reply to WeissensteinburgMar 10, 2008. 11:03 AM
I believe that alcohol can not be 100% at one atmosphere and room temperature. Being a gas it needs to be in a solution or it would evaporate.
Broom in reply to omnibotJun 26, 2009. 3:48 PM
"Being a gas" - ??? Alcohol is a liquid at one atmosphere & room temperature (STP). Maybe you mean that it has high volubility - it evaporates quickly.
omnibot in reply to BroomJun 29, 2009. 2:32 AM
It seems you're right, I had it mixed up with something else with those properties.
four_eyes954 in reply to omnibotMar 10, 2008. 7:06 PM
also people would start drinking it like ddum @$$es americans are, im from america and i can still see it happening. good were stupid
vestie in reply to four_eyes954Jul 19, 2009. 6:34 PM
Wow. I really hope you come to find that America is a group of relatively educated people.
thinkahead (author) in reply to WeissensteinburgMar 9, 2008. 10:48 PM
Distillation of Isopropyl results in an 89% azeotropic solution. In other words, 11% of the water in an azeotropic solution can not be separated by distillation. The remaining water can be removed by salting out. Starting with 808 grams of 91% Isopropyl and ending with 730 grams indicates that salting out does remove all of the water, leaving 100% Isopropyl.
thinkahead (author) in reply to WeissensteinburgMar 9, 2008. 8:57 PM
You can buy Isopropyl in 50,. 70, 91, and 99-100 percent solutions but 91% is the highest I've seen in drug stores. It is very suitable as a fuel without being salted out. That just goes to show you how really flammable the stuff is. I'm not sure what the percent Isopropyl is in the Isopropyl you can buy at auto stores made specifically to dry gasoline, although I suspect it is 99 or 100. I have not actually measured the difference in volume of Isopropyl before and after salting out. If you start with 1 liter of 50% Isopropyl azeotropic solution and you obtain a 1/2 liter of Isopropyl then it is pretty likely you have removed all of the water by salting out. If you obtain 3/4 liter Isopropyl then it is likely you have removed only half of the water by salting out. If you start with 1 liter of 70% Isopropyl azeotropic solution and you obtain a ~2/3 liter of Isopropyl then it is pretty likely you have removed all of the water by salting out. If you obtain more than 3/4 liter Isopropyl then it is likely you have removed only half of the water by salting out.
Weissensteinburg in reply to thinkaheadMar 10, 2008. 3:19 AM
You know what? I think I misunderstood part of the instructable. I read it as your salted out alcohol was 91%. Sorry.
thinkahead (author) in reply to WeissensteinburgMar 10, 2008. 4:12 AM
You probably read the note on the "An emergency pocket stove" picture that included using 91% alcohol as fuel so I changed the note to make it a little more clear.
Weissensteinburg in reply to thinkaheadMar 10, 2008. 1:42 PM
Yep, that was it. Thanks for clearing it up.
chuckr44 says: Mar 10, 2008. 9:16 AM
I'd be interested if you used a beer-making specific gravity meter for alcohol, to measure the SG of the alcohol your produced. Is it closer to 90%? Is this method efficient? Thanks for a great instructable.
thinkahead (author) in reply to chuckr44Mar 15, 2008. 10:48 AM
You are welcome and thanks for the compliment. Just as I was getting ready to build a hydrometer it dawned on me that all I really need to do is to measure volume and weight. I have a good postal scale and volume is also pretty easy to measure with just kitchen wear. All measurements so far confirm 99-100% Isopropyl.
Broom in reply to thinkaheadJun 26, 2009. 3:46 PM
Another great insight! You rock!
simplestatic says: Apr 19, 2008. 9:18 AM
Interesting process to know, but seems like a lot of work to get questionable purity IPA. I can currently get 99.99... technical grade isopropyl by the drum for roughly 7 cents an ounce(volume). Just find your local chemical company. They'll sometimes deliver at no extra charge too.
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