[komalshah]

Dear all,

I have 500ml 30% aqueous solution of acetic acid & i want to exact acetic acid from water.Which solvent i should select which can extract more acetic acid as well as can be reused.

I have following option with me,
ethyl acetate;
ethanol;
dichloromethane;
hexane;
acetic acid.
methyl isobutyl ketone

Your help will be highly appreciated.

Thanks,
Komal

[Don Shelly]

Your best chance of removing acetic acid from water is with a large column packed with a quaternary amine sorbent.  Just pour through and aspirate. 

[Gerard]

If a column packed absorption tower is too expensive for you liquid-liquid extraction will do or maybe distillation will do but the separation process cannot assure you of a very high purity yield since the distillate (for distillation) is still a mixture of your solute (HOAC) and solvent (water) and as with liquid liquid extraction your raffinate (unwanted product) may contain some solute (HOAC) and your desired product may now contain a mixture of the the new solvent, the old solvent and the desired product. I suggest you read the book entitled "Principles of Unit Operations" by Alan S. Foust read page 38 about Liquid-Liquid Equilibria where the common solvent is isopropyl ether where he treated water as a diluent.
-Gerard D. Ompad

[lucekali]

Hy
We did the liquid-liquid extraction of acetic acid with butyl acetat. I saw that on list of your chemicals is ethyl acetat so I think it would be the best solution for you. We did the extraction in Karr column extractor with pulsating perforated plates.
I don't know for the rest of your chemicals, but choosing the secondary solvent is very important and you have to know is it solvent toxic, flammable, high selection, possibility of regeneration by distillation etc.The solvent has to have a negligible little solubility in water.
Also you have to do an preliminar experiment to specify the equilibrium (ternar diagram) of your sistem (you can find in literature if someone already did it, but it's better do do it yourself and than compare yours and literature data).
good luck

[technologist]

Komal
I have worked on this system earlier & I know none of them will be cost effective if you are planning to use it industrially ( I am not sure that you are bothered about only 500 ml or more). Don has rightly pointed out the use of quarternary amines or you can mail me separately if you are looking for a good industrial process. I can help you in providing support.

[technologist]

Dear Lucekali
You said, you have used Butyl Acetate for Acetic acid extraction. I think its a good Idea..I didn't tried this. Can you share the distribution coefficient if you know from your experiment.