Archenemy_6 - 2-3-2017 at 18:24
So I'm attempting to distill some diethyl ether from a starting fluid advertising 50% ether. I saw a video about distilling the same brand and the
video had the ether coming over at about 35C. I applied light heat and stirring and the fluid starts bubbling while the temp reads 18C at the top of
the column which I assume is the propellants boiling at this point but I noticed I was also getting some fluid condensing into the flask at the same
temp. Is the propellants bringing over the ether and possibly some other things? Should I keep everything that came over before 35C?
JJay - 2-3-2017 at 18:44
That's a hard question to answer... I did that once, and I don't remember seeing much at all boiling below 34 C.
I probably wouldn't include the really low-boiling components in the final product, but if there seems to be a lot of low-boiling stuff, it might be a
good idea to redistill it. Clearly, substances that won't boil in the right range are not pure diethyl ether. Whether they might be something that
will cause problems with your intended use, I can't say.
Archenemy_6 - 2-3-2017 at 18:53
It seems quite a bit came over before even 30 C it does have a strong ether smell but I'll redistill it and see if I can get a closer to boiling temp
separation.
j_sum1 - 2-3-2017 at 18:56
Do you have a fractionating column? It sounds like you have some extra stuff in there.
Archenemy_6 - 2-3-2017 at 19:11
I have a 200mm Vigreux column that I'm using but I also have a 400mm that I could try. The MSDS shows diethyl ether 50-70%, petroleum gases liquefied
sweetened 10-30%, heptane and heptane ~15% carbon dioxide 5-10%,, petroleum distillates less than 1% and, toluene .15-.6%
[Edited on 3-3-2017 by Archenemy_6]
JJay - 2-3-2017 at 20:16
It's very easy to flood the column distilling starting fluid. It wouldn't hurt to use both together as a >60 cm column.
Archenemy_6 - 2-3-2017 at 20:40
I used about half my starting fluid and collected everything under 40 C. I'll do the same for the other half and combine them and redistill with both
columns. I'll have to find some way to set it up because of how tall it will be.
byko3y - 2-3-2017 at 21:08
It's really hard to get a pure ether from starting fluid, because they contain some paraffins with b.p. close to that of ether. If you want to get a
pure ether - do it yourself via EtOH and H2SO4. This route yields acetaldehyde acetals as a main impurity, which is removed by washing with bisulfite,
while i know no easy way to remove paraffins from the ether (very efficient fractioning will work, but most people have no access to such devices).
Fractioning on 5 theoretical plates will be enought for making grignard or simple extraction solvent, but this stuff is not sufficiently pure for
biotesting.
Archenemy_6 - 2-3-2017 at 21:24
The petroleum gases do list a boiling point of -40 to 80 C. I imagine this is probably the main impurity. I do mostly just plan on using it for an
extraction solvent but if it doesn't work out I'll look into the EtOH and HS2O4 method.