So, I'm making biodiesel. I try to separate out the newly formed esters from the glycerol and salts by adding water to a test tube, then the biodiesel on top. I VERY gently invert the tube once or twice, and keep getting a emulsion forming. The solution is completely golden yellow and very translucent. Once gently mixed it all becomes a cream color and cloudy.

 

How else can I remove glycerol? I tried ethanol but the esters are pretty miscible in it.

Edited August 2, 201510 yr by Elite Engineer

Centrifuge?

You might try pouring off the (mainly) diesel layer into a second container and adding salt to it then stirring.

You might try pouring off the (mainly) diesel layer into a second container and adding salt to it then stirring.Do

Would NaCl suffice or would ammonium sulfate or magnesium sulfate be necessary?

Would NaCl suffice or would ammonium sulfate or magnesium sulfate be necessary?

.

 

A solution of saturated NaCl should work.

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A solution of saturated NaCl should work.

Thanks!

In my experience, crystaline salt works better. I think the salt grains give the water something heavy to stick to

In my experience, crystaline salt works better. I think the salt grains give the water something heavy to stick to

 

I've never tried this myself, but that's a good suggestion (and one I'll definitely remember next time I have a tricky emulsion to get rid of).

Old chemist's trick (passed on to you all by an old(ish) chemist)