Sciencemadness Discussion Board

Smells surrounding distillations and reflux

oxybate - 12-6-2007 at 11:18

1. If an atmospheric distillation is setup and performed correctly, will there still be enough of a vapor escape to stink up a room if one is using an aromatic chemical. For example, if one were to distill eucalyptus oil to extract camphor, terpene, etc. Would the room smell strongly of this stuff? What about distilling DCM which is aromatic but less so...

2. If a vacuum distillation is setup and performed, how best can one eliminate odors? Using an non-rercirculating aspirator setup? If one wants to use a rercirculating aspirator setup, how then is oder-elimination best achieved?

3. If a reflux is setup and performed correctly, should there be significant odor despite effective condensation (lower than half-way up the condensor, which is cooled with ice-water)? Think of the eucalyptus oil example. If so, how best can one eliminate odor in this situation?

[Edited on 12-6-2007 by oxybate]

Organikum - 12-6-2007 at 14:02

A distillation with the right setup has not to stink. Another question is that at one point or the other you will have to dismantle the apparatus and then...

Lets see: Boiling flask - maybe column - condensor - receiving flask. That sounds like a pretty closed system except a venting opening at the receiver vessel which can in the case of an aromatic oil be equipped with a tube filled with activated charcoal. No smell.
Recirculating aspirator setup: What about a lid on the water container and a breathing hole with a charcoal filter?
Same for your reflux setup. Here it is even easier to fit a filter.

What makes me think you should read a little bit more before going into modus operandis is:
- DCM is no aromatic, really not

I did (and do now again) a lot of experiments in a somehow smell sensitive environment. The real problem occurs normally not during the reactions - this can be taken care of, the problems come when it is time to dismantle the setup and to clean the glassware.
Had for example no problems whilst making monochloroacetone. Cleaning the glassware put me plain out despite I had soaked it in conc. NaOH for two days. That was not funny.


/ORG



[Edited on 12-6-2007 by Organikum]

woelen - 12-6-2007 at 14:11

I have the impression that the word 'aromatic' is used in two totally difficult ways. In oxybate's post I simply read the word as 'smelly'. In Organikum's post I read about the electronic (resonance stabilized) structure. In that sense, DCM is not aromatic, not at all, but in the 'smelly' sense, I would say that DCM definitely has some 'aroma' ;).

The_Davster - 12-6-2007 at 16:32

If doing a vaccuum filatration using a water aspirator for vaccuum, a tube can be hooked up to the water exit on the aspirator, and shoved far down the drain, past the U trap, and no smells escape.