Sciencemadness Discussion Board

Strange result from a glycerol and soap production trying

Steamboy - 1-2-2017 at 09:10

I was trying to make glycerol.
For this, I decided to use the classical soap method (mix water with NaOH and vegetable oil), but with an extra addition of salt (NaCl) for increase the efficency of glycerol production and avoid soap solidification.

However I obtained an strange result, the liquids that I created are three layers, instead of only the two: soap, and the water with glycerol and salt.


Description of liquids:

The most light layer seems a kind of oil, yellow and insoluble to water. However this "oil" is unable to react with caustic soda again.
What is this? I will do a test of flammability, but I don't think this might be biodiesel or something so... At least, this method is supposed to not be valid for create biodiesel, or shouldn't be.

The second layer, white and viscous, seems to be soap, but is very fluid.

And the third layer is soluble in water and has an sweet "alcoholic smell"... possibly this is the glycerol and salt dissolution that I want to create.


Can someone help me?

[Edited on 1-2-2017 by Steamboy]

Dr.Bob - 1-2-2017 at 13:43

If no methanol was added, then there is no biodiesel. I would guess that you have failed to complete the reaction, likely by not following a real prep, so you still have veg oil on top, then soap in the middle, then some glycerol/water on the bottom. There are many preps for both soap and biodiesel, both of which provide glycerol, so find one and follow it carefully. I've managed to make biodiesel, so it can't be too hard.