How to "Salt Out"

230,424

202

192

Introduction: How to "Salt Out"

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.

Step 1: Start by Adding the Table Salt

Fill the empty jar about 1/4 full with table salt

Step 2: Add the Hydrated Isopropyl Alcohol

Fill the jar about 3/4 full with hydrated (50% to 70%) Isopropyl alcohol

Step 3: Shake Contents Vigorously

Put the lid on the jar, close to seal the contents and shake jar vigorously to be sure the salt and water combine.

Step 4: Let Gravity Separate the Contents

Place jar on a level surface long enough for the alcohol and salt water to separate (15 to 30 minutes).

Step 5: Keep the Two Layers Separate

Open jar carefully so as not to remix the two layers.

Step 6: Extract the Isopropyl Alcohol

Use the turkey baster to extract the top layer, which will be the Isopropyl alcohol.

Step 7: Fill the Receiving Bottle

Fill a receiving bottle with the turkey baster Isopropyl contents.

Step 8: Label Bottle

Label the bottle "Dehydrated Isopropyl Alcohol"

Step 9: Use Your Dehydrated Alcohol

Use in an alcohol stove, lamp, torch, etc. or to give your pet a nice alcohol rub down.

Step 10: Addendum

You may find that your salted out Isopropyl leaves a salt residue when it is burned. In many applications like a pocket stove the salt residue will continue to serve in the role of helping to separate the Isopropyl and the water when water intrusion occurs from dampness, rain or boil overs.

In other applications the salt residue may not be desired. To separate the salt residue from the Isopropyl use a homemade still. In this case your are not distilling an azeotropic solution of Isopropyl and water but rather separating a liquid from a dissolved solid.

The diagram below illustrates the required components for such a still.

1 Person Made This Project!

Recommendations

  • Backyard Contest

    Backyard Contest
  • DIY Summer Camp Contest

    DIY Summer Camp Contest
  • Fruit and Veggies Speed Challenge

    Fruit and Veggies Speed Challenge

192 Comments

0
steviefun691
steviefun691

5 weeks ago

"Salting Out" isopropyl alcohol will NOT and i repeat will NOT give you anywhere near 99.9% ISO. at very best you may get 80-82%.

0
Mikie-z
Mikie-z

Reply 11 years ago on Introduction

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.

0
samuelx3
samuelx3

Reply 7 months ago

quite a bit late but iodized salt really doesn't have that much iodine.

0
dammat
dammat

12 years ago on Introduction

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.

0
Broom
Broom

Reply 12 years ago on Introduction

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).

0
DamithaN
DamithaN

Reply 8 months ago

Silica won't react with IPA but it will absorb both water and the IPA

0
Gourdhead
Gourdhead

Reply 1 year ago

They make screw-on filters like car oil filters using that very thing -- silica -- for gasoline dispensers! Or you can strain it through an unused baby diaper!

0
botronics
botronics

8 years ago on Introduction

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.

0
Broom
Broom

Reply 5 years ago

botronics, think about it. You're asking if it will remove water from the methanol in vodka - so you can mix it with camphor, ammonium chloride, potassium nitrate, and WATER.

0
spinney1963
spinney1963

Reply 1 year ago

The alcohol in vodka is ethanol. Methanol is poisonous!

0
botronics
botronics

Reply 5 years ago

The water content of Vodka is too high for the Fitzroy Weatherglass formula. That why I need to get the water out before mixing it.

0
Broom
Broom

Reply 5 years ago

Oh! Thanks. Did not realize that.

0
yzrider3000
yzrider3000

Reply 7 years ago on Introduction

sounds like a illegal substance lol starts with a m

0
Broom
Broom

Reply 5 years ago

If you're hinting at "methanol", it's not illegal. If not... you need to put down the bong, because you're not making sense.

0
fenomen09
fenomen09

Reply 6 years ago

MgCl?

0
simplestatic
simplestatic

13 years ago on Introduction

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.

0
orionjoynes
orionjoynes

Reply 3 years ago

But it's so much more fun to make it yourself.

0
Broom
Broom

Reply 5 years ago

Maybe you should post that as your own instructable...

How to Get 99.99%-Pure Isopropyl Alcohol.

Step 1: Buy it.

You could start your own Instructable channel! Think of the possibilities.

"How to Make a Wedding Ring from Paper Money"

"How to Build a Mercedes Benz at Home, With Just Tens of Thousands of Dollars And a Ride to the Dealership"

"Build Your Own House, Using a Mortgage and a Contractor"

0
thinkahead
thinkahead

Reply 13 years ago on Introduction

I'm guessing but most people would only use 99% Isopropyl for backpack fuel and purity can be asserted with a post-salting out distillation. If you camp every weekend this is no more than a 32 fl oz bottle of fuel per month. A 55 gallon drum contains 7040 fl oz which would last the every weekedn backpacker about 18.3 years and since the price of Isopropyl has increased by 50% in the last year buying a whole drum now might actually pay off down the road. No harm in posting the name of your supplier...