Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: molecular sieve capabilities
Hazard to Self

Posts: 87
Registered: 3-7-2009
Location: The Jungle(neezeelund)
Member Is Offline

Mood: Financial

[*] posted on 3-9-2011 at 13:40
molecular sieve capabilities

Hey guys,

I recently got about 5L of molecular sieve from a solvent recycling place for free, and I was just wondering what the capabilities of these sieves are?

Among drying out ethanol(it's a water absorbing sieve), I was thinking that it might be possible to circumvent the whole h2so4 distillation process for concentrating 70% nitric, and simply use this sieve to absorb most of the water.

Provided the sieve won't absorb the nitric acid molecules, (it's carbon molecular sieve btw), and that it won't react with the nitric, could this work? Will I have to distill it anyway, as opposed to just decanting off the nitric and leaving the beads?

"If an injury has to be done to a man it should be so severe that his vengeance need not be feared."

Before you find youself cheering for a new regulation, consider your reaction if you were to be on the receiving end.
View user's profile View All Posts By User
Hazard to Self

Posts: 52
Registered: 25-1-2011
Location: Scandinavia
Member Is Offline

Mood: No Mood

[*] posted on 10-10-2011 at 07:52

You'd have to know which type of mol. sieve you have first and
whether they are "activated". A good way to test this is put a
bit of spit in the palm of your hand (preferably your own) and
add one mol sieve to it. Crude but generally an effective
indicator test. It should get hot if it reasonably activated. If it
only warm-ish it not that great, but will absorb some moisture
from solvents.
The pore size defines which solvents it is most suited for. 4Å is
good for DMF, pyridine, dioxane, ether or chemical reactions. 3Å
is better for methanol or ethanol. 5Å toluene and xylene. I've
never tried to put mol. sieves in mineral acids, so unsure on the
effects there.
On can reactivate mol. sieves but it is useful to know which
solvent has been in there before since most are toxic, smelly
and flammable. You need a good vacuum pump though.

Good luck

If it ain't broke don't fix it....
Now where are my screwdrivers? ;)
View user's profile View All Posts By User

  Go To Top