Sciencemadness Discussion Board

my ethanol is corrosive

CouchHatter - 8-3-2022 at 18:46

I have some denatured ethanol from a drum, and it smells like those bubble straw toys from the 90s. It is quite corrosive to metal: I used it to refill a 1-gal steel Crown can (which originally contained "denatured alcohol") but it quickly turned rust-brown and ate through the can in a few months. It also leaked from a 1-gal HDPE jug and totally corroded the finish on a set of steel drill tips.

-Are the denaturants likely making it more corrosive than pure ethanol?
-What sort of home tests could determine likely denaturants?
-Which types of reactions might it be unsuitable for in its current state?

I thought it might be a good source of Bitrex, but I don't want to also have other crap like pyridine.

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Ormarion - 8-3-2022 at 23:32

First thing i would recommend you is to be sure if it is ethanol itself, best would be a GC and a IR spectrum but i believe you don't have such equipement.

You can probably do the following test:
pH, density, residue (evaporating it and see if there is any solid left), boiling point, solubility wih water. I have personally never heard about corrosive ethanol.
Please be careful when working with it

draculic acid69 - 9-3-2022 at 01:54

First thing U should do is stick a p.H. strip in and see if U get a weird result.
Alcohol has no p.H.
And no there shouldn't be anything in there that is causing the problems your seeing

Lionel Spanner - 9-3-2022 at 03:50

In my experience denatured alcohol can be stored perfectly well in metal and HDPE containers, which suggests what you have is something else.

Also, bubble straw toys contained acetone and ethyl acetate, so if it smells like that, that's another sure sign it's not alcohol at all. Denatured alcohol smells like methylated spirit.

macckone - 10-3-2022 at 18:21

It doesn't take much water to cause steel to rust.

markx - 14-3-2022 at 02:15

"Denatured alcohol" can actually be a mixture of many things, among others also ethyl acetate and several esters. Often EAF (ester aldehyde fraction aka heads) from ethanol production is used as denatured alcohol. The esters can break down over time due to various factors, liberating acids in the process...these in turn can cause corrosive effects upon contact with metallic items. E.g. as an experiment I used EAF as fuel in lawn mover and although it worked, it also caused severe degradation due to corrosion in the carburetor of the machine.