[Cuttnhorse]

"The ethanol is mixed with a poison to render it undrinkable and hence no threat to the alcoholic beverages tax structure."

Not that I'm doubting you, but do you have a reference for this little tidbit of info???

[tlb]

http://en.wikipedia.org/wiki/Denatured_alcohol

Denaturing alcohol does not chemically alter the ethanol molecule. Rather, the ethanol is mixed with other chemicals to form an undrinkable mixture.

Different additives are used to make it difficult to use distillation or other simple processes to reverse the denaturation. Methanol is commonly used both because of its boiling point being close to that of ethanol and because it is toxic.

Denatured alcohol and its manufacture are a public policy compromise. The supply and demand for denatured alcohol arises from the fact that normal alcohol (which in everyday language refers specifically to ethanol, suitable for human consumption as a drink) is usually very expensive compared to similar chemicals, being highly taxed for revenue and public health policy purposes (see sin tax). As a result, if pure ethanol were made cheaply available as a fuel or solvent, people would drink it.

Denatured alcohol provides a solution to permit legitimate use and manufacture of ethanol, whereby cheap ethanol can be made available for non-consumption use without the risk of it being converted for consumption.

[NVDave]

Ask an engineer and ye shall receive:

http://www.aventinerei.com/pdfs/fuel_grade_spec.pdf

If the methanol doesn’t make you go blind, the corrosion inhibitors and gasoline added (min 2%) will get you but good.

Really. Don’t mess with it as drinkin’ likker. Get some copper pipe and build a still instead.

[NVDave]

Oh, and if you want the deep and dirty info, you need to order your own copy of ASTM D4806:

http://www.astm.org/Standards/D4806.htm

It will tell you, literally, everything you never wanted to know about what is going into your gas tank with ethanol.

[neverdem]

Not that I'm doubting you, but do you have a reference for this little tidbit of info???

Specialty denatured alcohols are denatured alcohol formulations intended for a particular industrial use, containing denaturants chosen so as not to interfere with that use. While they are not taxed, purchasers of specialty denatured alcohols must have a government-issued permit for the particular formulation they use and must comply with other regulations.