Stibnut
Harmless
Posts: 43
Registered: 4-6-2015
Member Is Offline
Mood: No Mood
|
|
Drying formic acid with molecular sieves - CO risk?
I've got a very basic question. If I have 95% formic acid, and I want to make it anhydrous, would 4A molecular sieves be a good choice for drying?
The main reason I ask is that I don't want to accidentally evolve CO. Does anhydrous formic acid decompose much more rapidly than 95%, and is there
any chance that molecular sieves would catalyze this decomposition?
|
|
|
Cryolite.
Hazard to Others
Posts: 269
Registered: 28-6-2016
Location: CA
Member Is Offline
Mood: No Mood
|
|
You wouldn't form carbon monoxide, but you would destroy your sieves! Molecular sieves do not tolerate acid.
|
|
|
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
And he will also contaminate his formic acid with soluble stuffs from the reaction of the molecular sieve with the acids...
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
Stibnut
Harmless
Posts: 43
Registered: 4-6-2015
Member Is Offline
Mood: No Mood
|
|
D'oh! Okay, I won't try that.
What about MgSO4?
|
|
|
Boffis
International Hazard
Posts: 1867
Registered: 1-5-2011
Member Is Offline
Mood: No Mood
|
|
Formic acid is up-graded by azeotropic distillation, usually with n-heptane or a petroleum ether with a close boiling range. The formic acid distils
over preferencially with the heptane. I have tried it but its not as easy as it sounds as a batch process because a lot of heptane distils for a small
amount of acid so you need a system to recycle the heptane continously and thats where it gets complex.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
