Is there a method to go from denatured alcohol to re-natured alcohol? What changes are involved in denaturing alcohol to begin with?
Alcohol has to be denatured because it forms an azeotrope with water. Essentially, what this means is that if you distill it, some water molecules carry over with the alcohol molecules (5%, I believe). You have to add a denaturant to disrupt the azeotrope.
You could easily renature it by mixing it with a bunch of water and then re-distilling it. Assuming that there was essentially no denaturant left in there it’d work. If you had some still in there (which is why drinking denatured alcohol is a bad idea: it may have benzene in it), then you might have to separate them first.
From my brush with organic chemistry, “denaturing” implies weaker (secondary) bonds are broken hence allowing the molecule to flex and change shape…while the stronger bonds remain intact, hence keeping the molecular formula the same. [At best, I’d WAG a denatured state of a molecule is one (of many) isomers of said molecule.]
For example, the protein molecure in egg white is albumin. It is held in an “S” shape by weak, sulfur bonds (i.e.: secondary bonds which form between adjacent sulfur atoms.) Adding heat energy from the stove quickly breaks these bonds causing the molecule to take on a new, unnatural shape. Hence, it is now said to be a “denatured” protein, or more generally speaking, a “denatured” molecule.
Hydrogen also readily forms such weak bonds, too. We don’t think mcuh about it, but water, for example, has these same weak hydrogen bonds formed between adjacent molecules. IIRC, it is the source behind surface tension. (There are other weak forces at play, as well…like London forces, but I have forgotten how those finer points play into causing surface tension, if at all.)
I would make an educated WAG these weak (or secondary) bonds could be readily reformed under the right (lab) conditions. But, I doubt they would quickly reform on their own, i.e.: a can of denatured alcohol would not readily reform back to its natural state.
I ain’t an organic chemist, but I’ve dabbled a bit…but, so did Dr. Frankenstein!
- Jinx
Denaturing alcohol does NOT involve disrupting azeotropes, or rearranging weak chemical bonds. Alcohol is denatured by putting something in it, like methanol, benzene, or fusel oil that renders the stuff undrinkable. There are many different kinds of denatured alcohol, with additives that render it a) undrinkable and b) suitable for a specific use or range of uses.
If you happen to know the particular denaturants added to a batch of alcohol, it is usually possible to remove them. Distillation, chemical seives, chromatography on silica columns etc. will all work to remove some denaturants, but the whole point of denaturing is to render the alcohol undrinkable, and more trouble than it’s worth to convert into something that is drinkable.
What Squink said. Only ethanol would be denatured. It is contaminated with some denaturing agent(s) from a list of appropriate chemicals. You don’t which particular agent(s) are in any given batch. For certain manufacturing and research purposes, there’s a way to obtain a batch whose denaturing agents won’t impede the intended use.
These shed a little light on it:
http://www.pharmco-prod.com/pages/faq.html (scroll down to #s 18 & 19)
http://laws.justice.gc.ca/en/E-14/C.R.C.-c.568/text.html
http://www.atf.gov/about/service/sda/
Squink is correct on this one:
From here.
Like I (meant to have) said, you don’t know which agents are used, in most cases anyway. The whole point is for it to not be easy to restore the stuff to drinkability.
Certainly it’s possible! Back during Prohibition my home town used to buy denatured alcohol in bulk, take it to the chemical works, and distill out the ethanol, then ship it up to New York City to be sold.
Really. This is really a bad idea.
It qualifies a truly stupid.
(Ethyl) Alcohol is denatured with additives that are very difficult to separate by distillation, because they have very similar boiling points to that of (ethyl) alcohol. If methyl alcohol boils at 100 degrees and ethyl alcohol boils at 101 degrees, how are you going to regulate the temperature that finely?
You have me so worried I’m not even checking the text books right behind me for the actual boiling points.
Please note that CalMeachum’s town’s people sent the distillate away to New York.
It may be truly stupid, and I certainly don’t recommend it, but it was done – I’ve looked up the articles (in the New York Times, no less), so I know that there was a lucrative business going on doing this.
My understanding was that denaturin was generally done with benzene, though, not methyl alcohol. There ought to be enough difference there so that distillation wouldn’t be impossible.
NOTE: Don’t Try This at Home.
I think you’ve got your temperatures off there. Distillation of methanol from ethanol is an easier and less energy-intensive distillation than ethanol from water. If you had a good distillation and spilled a lot of ethanol over with the methanol, you could produce a safe batch of ethanol. I don’t know how they would have tested the methanol percent the first few batches to make sure they were doing it correctly, though.
That being said, a little water in your ethanol won’t be harmful. I don’t know how much methanol the body can tolerate in a glass of bathtub gin.
the companys could care less if we drank the alcohol they denatured it for the sole purpose of not having to pay the liquor tax if it wasn’t drinkable they didnt have to pay excise fee always about the money lol
Slight hijack: I used to work at a chemical plant that produced ethanol as a byproduct. It came out pretty pure, and was loaded into a tanker trailer. When that was “full”, it was trucked a short distance to a gas station and enough gasoline was added to denature it. Detailed records of the process had to be maintained to meet BATF regulations and avoid taxes that would have been applied had it not been denatured; and it was sold to industrial ethanol customers.
Separating the ethanol from the gasoline to make it drinkable again would be much more costly than it was worth; you’d have to be pretty desperate to do it, IMHO.