Carbon - How do it know?
- I was puzzled how carbon treating neutral spirit could remove heads
(lighter stuff) and tails (heavier stuff), but leave the middle. Some
sort of molecular "band-pass" filter?...unlikely.
Now I know how it know! I work with a bunch of Chem E's.
They helped me sort it out.
Ethyl Acetate(heads)88.1 Molecular Weight(MW) 77.1C Boiling
Ethanol 46.1 MW, 78.4C BP
2-Propanol (Tails) 60.1 MW, 82.3 BP
I assumed BP was related to MW, but its not. The
compound of the three above with the highest MW is
Ethyl Acetate @ 88.1 MW. It's BP is real close to
ethanol, so it is difficult to separate with
distillation. 2-Propanol on the other hand has a BP
far enough away for it not to be a huge problem unless
you really screw up. And if you do screw up, you still
have a chance to remove it with carbon because its MW
is larger than ethanol.
Now on to the carbon. "Distillers" carbon is designed
to have a pore size that traps the large molecules
(ethyl acetate and maybe propanol) while letting the
smallest (ethanol) pass through.