unreacted veg oil in Manufacture of Biodiesel

[Ivan]

Does anyone know if an incomplete reaction results in some unreacted veg oil in the glycerine layer? I think conventional thinking is that it will be in the biodiesel layer, but I just wondered if anyone had checked if some ends up in the glycerine.....

[mespilus]

Glycerol is hygroscopic and totally miscible with water,
so should show little solubility in, or little solvency for, veg oils.

With a density of 1.26 as opposed to veg oils typical less than 0.9,
it should separate.

However, a partial reaction leading to soap formation will easily form an
emulsion of the oily materials in any water present.

[Ivan]

Thanks!