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https://en.m.wikipedia.org/wiki/Azeotropic_distillation https://en.m.wikipedia.org/wiki/Azeotropic_distillation You can't distill ethanol to 100%, only 95%. To

https://en.m.wikipedia.org/wiki/Azeotropic_distillation https://en.m.wikipedia.org/wiki/Azeotropic_distillation You can't distill ethanol to 100%, only 95%. To get the last 5% of water out you typically add benzene or cyclohexane, which remains as a trace contaminant in the final product. Also note that methanol (and other unsavory small molecules) normally contaminate distilled ethanol unless you actively take steps to remove them. For something you intend to drink, you need to carefully control fermentation to reduce the amount of methanol, toss out the early distillation fractions to remove as much methanol as you can, and then let your remaining distillate sit in an open tank for a couple of weeks to let whatever methanol remains evaporate off (along with some of your product). If you're making ethanol as an industrial solvent or fuel, you don't need to do these things. It's not crazy that under prohibition, taking all those extra steps would be seen as evidence of an intention to violate the law and make drinkable spirits. But whatever, Slate says it was a conspiracy to poison poor people, I'm sure that's the right explanation.

loeg 10y ago
> By mid-1927, the new denaturing formulas included some notable poisons—kerosene and brucine (a plant alkaloid closely related to strychnine), gasoline, benzene, cadmium, iodine, zinc, mercury salts, nicotine, ether, formaldehyde, chloroform, camphor, carbolic acid, quinine, and acetone. I don't think any of those are just natural byproducts of making high proof industrial alcohol. Or do you contest that claim?
- azeotropic 10y ago
  Formaldehyde could happen by accident during the process (it's the aldehyde form of methanol). The organic solvents (kerosene, gasoline, benzene, ether, chloraform, carbolic acid, acetone) would be used to break up the azeotrope during distillation to 100% ethanol. You can't make 100% ethanol without making it poisonous. It's still poisonous now that prohibition is over. The rest are primitive bitterants of one form or another to make poisonous denatured alcohol less palatable-- they're there to save lives by making it so disgusting that you spit it out instead of swallowing it. We still add bitterants to denatured alcohol (and to rubbing alcohol, and nail polish, and spray cans), but they're way more bitter than any of those. You're just freaking out because the chemicals sound scary. The author goes out of his way to mention strychnine just to scare you about brucine, but it's still used as a bitterant. Look I don't doubt some people callously said people who died or went blind drinking denatured alcohol or wood alcohol got what they deserved because they shouldn't have been drinking it anyway. I do doubt that these things were put in industrial alcohol to kill people. The bitterants are there for the exact opposite reason.
oxide 10y ago
>It's not crazy that under prohibition, taking all those extra steps would be seen as evidence of an intention to violate the law and make drinkable spirits. I naively walked around this planet giving the benefit of the doubt to anything and everything as well, for a long, long time.
nkurz 10y ago
If you're making ethanol as an industrial solvent or fuel, you don't need to do these things. Your chemistry is solid, but your argument depends on the poisons being a natural fermentation byproduct rather than an federally mandated addition done at extra cost to the producer. In fact, the government increased the required level of methanol with the explicit goal of making it too difficult to remove completely. They did this conscious of the fact that those who drank the improperly purified product would be blinded or killed, and justified this by pointing out that the consumption was illegal. But whatever, Slate says it was a conspiracy to poison poor people, I'm sure that's the right explanation Slate published the article, but the author is extremely well credentialed: Pulitzer Prize, director of the Knight Science Journalism program at MIT, author of a recent book on the topic: http://deborahblum.com/Author.html http://deborahblum.com/Author.html. You can read the introduction to relevant chapter from the book here: https://books.google.com/books?id=O2HqmJtFkDIC&pg=PT76&lpg=PT76#v=onepage&q&f=false https://books.google.com/books?id=O2HqmJtFkDIC&pg=PT76&lpg=P...

loeg 10y ago

> By mid-1927, the new denaturing formulas included some notable poisons—kerosene and brucine (a plant alkaloid closely related to strychnine), gasoline, benzene, cadmium, iodine, zinc, mercury salts, nicotine, ether, formaldehyde, chloroform, camphor, carbolic acid, quinine, and acetone. I don't think any of those are just natural byproducts of making high proof industrial alcohol. Or do you contest that claim?

azeotropic 10y ago
Formaldehyde could happen by accident during the process (it's the aldehyde form of methanol). The organic solvents (kerosene, gasoline, benzene, ether, chloraform, carbolic acid, acetone) would be used to break up the azeotrope during distillation to 100% ethanol. You can't make 100% ethanol without making it poisonous. It's still poisonous now that prohibition is over. The rest are primitive bitterants of one form or another to make poisonous denatured alcohol less palatable-- they're there to save lives by making it so disgusting that you spit it out instead of swallowing it. We still add bitterants to denatured alcohol (and to rubbing alcohol, and nail polish, and spray cans), but they're way more bitter than any of those. You're just freaking out because the chemicals sound scary. The author goes out of his way to mention strychnine just to scare you about brucine, but it's still used as a bitterant. Look I don't doubt some people callously said people who died or went blind drinking denatured alcohol or wood alcohol got what they deserved because they shouldn't have been drinking it anyway. I do doubt that these things were put in industrial alcohol to kill people. The bitterants are there for the exact opposite reason.

oxide 10y ago

>It's not crazy that under prohibition, taking all those extra steps would be seen as evidence of an intention to violate the law and make drinkable spirits. I naively walked around this planet giving the benefit of the doubt to anything and everything as well, for a long, long time.

nkurz 10y ago

If you're making ethanol as an industrial solvent or fuel, you don't need to do these things. Your chemistry is solid, but your argument depends on the poisons being a natural fermentation byproduct rather than an federally mandated addition done at extra cost to the producer. In fact, the government increased the required level of methanol with the explicit goal of making it too difficult to remove completely. They did this conscious of the fact that those who drank the improperly purified product would be blinded or killed, and justified this by pointing out that the consumption was illegal. But whatever, Slate says it was a conspiracy to poison poor people, I'm sure that's the right explanation Slate published the article, but the author is extremely well credentialed: Pulitzer Prize, director of the Knight Science Journalism program at MIT, author of a recent book on the topic: http://deborahblum.com/Author.html http://deborahblum.com/Author.html. You can read the introduction to relevant chapter from the book here: https://books.google.com/books?id=O2HqmJtFkDIC&pg=PT76&lpg=PT76#v=onepage&q&f=false https://books.google.com/books?id=O2HqmJtFkDIC&pg=PT76&lpg=P...