Sciencemadness Discussion Board

evaporation

Slimz - 24-9-2007 at 15:23

is there a fast way to evaporate water that does not involve heat?? this may sound silly but i figured i'd ask...

Ozone - 24-9-2007 at 15:29

The process of phase transition involves the transfer of energy (heat or other). You can minimize the *heat* needed by using:

Vacuum. Lyophillization. Azeotrope with acetone and blow down with air/N2.

You will not, overall, invest any less energy.

I know this is covered, at least in oblique fashion, elsewhere on this site...

cheers,

O3

smuv - 24-9-2007 at 15:32

drawing a Vacuum, blowing air over the water, also adding a solvent that is miscible with water which has a lower boiling point (acetone). Or combinations of what was listed.

Slimz - 24-9-2007 at 15:43

thanks

Slimz - 24-9-2007 at 16:11

ok so if i add acetone to water that conatins an organic like an amine wich is polar (not sure if that maters) would the acetone have any adverse effects on that organic material?

and should we move this to the organic board now...?

[Edited on 24-9-2007 by Slimz]

The_Davster - 24-9-2007 at 16:21

Quote:
Originally posted by smuv
blowing air over the water


In a low dish this works awesome. It is my prefered evaporation technique. A computer fan over a petri dish for small ammounts of liquids(even in water) works overnight.

Moved to beginnings.

Blind Angel - 24-9-2007 at 17:47

Amine are polar, keep that in mind. Acetone is fairly inert as long as it's not in extreme condition, which would in any way degrade your product, so in your case there are no needs to worry on that. In fact we use mostly acetone in organic lab due to it's inertness and is ability to make water evaporate faster. Depending on how much you have some method would be easier and more recommendec. As The_Davster said, simply use a shallow dish, such as a petri or if you don't have a cookies pan or a simple plate, and put a fan over it, it should be dry overnight. The thinner the layer of water will be the shorter time it will take, but the product will be more disperse. Vaccuum can help a lot when using bigger quantity with small concentration and applying a very small amount of heat, but require more equipment. I never tryed lyophillization.
Simply take what's best for you.

chemkid - 24-9-2007 at 18:00

"In a low dish this works awesome. It is my prefered evaporation technique. A computer fan over a petri dish for small ammounts of liquids(even in water) works overnight. "

I think i'll try that. I've had some sodium bisulfate drying, what, a week now?

12AX7 - 24-9-2007 at 23:40

I have a ventilated cabinet with switched heating elements. It works quite nicely for almost everything.

Tim

Slimz - 25-9-2007 at 11:38

that's a great idea.. i could filter the inflow of air to keep out particulate .. gonna do some carpentry...

hodges - 25-9-2007 at 15:31

Quote:
Originally posted by chemkid
"In a low dish this works awesome. It is my prefered evaporation technique. A computer fan over a petri dish for small ammounts of liquids(even in water) works overnight. "

I think i'll try that. I've had some sodium bisulfate drying, what, a week now?


Sodium bisulfate is hygroscopic, so it probably never will dry on its own unless you live in a desert climate.

Hodges