How can i make pure, or close to pure, alchohol?

Question

can i make 90% rubbing alchohol into near 100% alchohol? if so, how?

yeah im not trying to drink it, im not stupid. i want highly potent alchohol for my hybrid rocket engine. it runs mildly on 90% rubbing alchohol but not what i want. the point of this project is to make it run off of alchohol, so no other suggestions please.

Answer 1

First question is what kind of alcohol do you want. There are three principal kinds in common use: methyl, used as a solvent and chemical reactant, poisonous; ethyl, used as a solvent, fuel, and for drinking; and isopropyl, a principal ingredient in rubbing alcohol. Next question is what do you plan to use as a feedstock? Usually, alcohol is made by distillation to remove water, but no alcohol can be made completely pure by this means, as the vapor pressure of the alcohols is not sufficiently different from the vapor pressure of water. If you are dealing with ethanol, have a chat with somebody from the ATF.

Answer 2

I hope you realize that rubbing alchohol is poisonous isopropyl alchohol and NOT the same as the ethyl alchohol people drink!!!

Soothsayer gets my vote on this one. Isopropyl alchohol becomes an azeotrope at around 87% and cannot be concentrated further by distillation, where as ethyl alchohol become an azeotrope at around 96%. Wasn't aware of the difference. Leaving my answer up because the warning about drinking isopropyl alchohol cannot be stressed enough here.

Answer 3

As others have noted, isopropyl rubbing alcohol probably isn't what you want; however, Everclear grain alcohol is 95% ethanol.

With either of these solutions, you can get a drying agent and remove the water. Pick up a carton of "DampRid" (reference 1), which is prilled anhydrous calcium chloride. This will remove much of the water from the ethanol or isopropyl, drying it quite effectively.

Answer 4

Use of some sort of drying agent would be the easiest way if you have it at your disposal. Anhydrous Magnesium Sulfate would do the trick. Add it until it stops clumping. Large scale purification isn't really worth it as the stuff is pretty cheap and commercially available.

Answer 5

No matter what method is used to purify it, alcohol will not remain at 100% purity very long if exposed to normal atmosphere. It will absorb moisture from the air and dilute itself. I believe for ethanol, 90% is the highest purity that can be sustained.

Answer 6

you have to use a dessicant that will absorb the water. you could try distill it, but since the alcohol and water is in azeotrope form, you need to employ some special distillation methods that will break this. using dessicants is probably the easiest method to try.

Answer 7

you dont want pure alcohol. if you should happen to get some and try to drink it you will kill yourself the body cant handle it