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Specialty Chemistry Forums => Citizen Chemist => Topic started by: Yuvaltamir on May 23, 2018, 03:56:18 AM

Title: Need Help in a Lab
Post by: Yuvaltamir on May 23, 2018, 03:56:18 AM
Hello,
I work in a lab and we produce some kind of fuel. The reaction leaves us with ethanol, glycerin, and NaOH, we want to isolate each. Do you know what will be the most efficient (and cheapest) way to seperate those molecules in a solution?
Thank you!
Title: Re: Need Help in a Lab
Post by: Enthalpy on May 23, 2018, 04:26:52 AM
Welcome, Yuvaltamir!

You mean, everything dissolved in water?

Ethanol would evaporate first, followed by water, both being difficult to separate well. You can check what happens at alcohol distilleries.

Both glycerine and NaOH stay strongly bound with some residual water. I ignore how to separate these two. A high temperature would evaporate water away conveniently. Maybe NaOH settles down as you evaporate the water?

You'll make your life easier if you accept some losses and a limited purity, like 80%+20% ethanol+water. If you seek to reuse these compounds, maybe it's good enough.
Title: Re: Need Help in a Lab
Post by: Yuvaltamir on May 23, 2018, 06:46:21 AM
Thank you!
So after the evaporate step Ill stay with the Glycerine and NaOH, and some water. NaOH is soluble in Glycerine... and they both soluble in water. maybe get rid of all the excess water and add << ether? (NaOH is insoluble in that compound) and centrefouge to seperate?
Title: Re: Need Help in a Lab
Post by: Babcock_Hall on May 23, 2018, 09:38:39 AM
It sounds as if you may be making biodiesel.  Have you searched the chemical literature for information on how others have approached this problem?