What is the glycerin layer (aka "glycerin")?
Glycerin is the byproduct left over after the biodiesel reaction process is complete. In a BioPro™ 190, at the end of the two-step reaction process, there will be 50 gallons of biodiesel in the main tank resting above 10-12 gallons of glycerin. (In the BioPro™ 380, this will be 100 gallons of biodiesel atop 20-24 gallons of glycerin).
This glycerin is usually dark brown and has a thicker viscosity than reacted biodiesel which is usually a honey brown color. Before moving to the wash cycle, your glycerin must be drained out of the tank at the ball valve and captured in a separate container.
WHAT DO I DO WITH MY GLYCERIN?
There are many options.
Here is the Short List:
1. Put it in our GL-95 Glycerin Demethylator (now available). This will remove the methanol from the glycerin and leave you with a quickly cooling block of glycerin soap. The soap can be further refined or thrown away. The methanol is approximately 90% pure and, with a little further refining, can go back in your BioPro™.
2. Make soap.
3. Feed your glycerol to cattle.
http://www.make-biodiesel.org/Dealing-with-Byproducts/feeding-glycerin-t... http://www.livestocktrail.uiuc.edu/uploads/dairynet/papers/2007%20dd%20G... http://cabiblog.typepad.com/hand_picked/2007/05/glycerol_a_bypr.html http://jas.fass.org/content/87/2/632.full http://www.sciencedaily.com/releases/2011/01/110119182818.htm
4. Take it to a sewage treatment plant where they have an “anaroebic digester”. THough they probably won't pay you for it, they do welcome the stuff.
5. Use it as a composting agent.
See Dickinson college study.
6. Use it as a dust suppressant.
7. Burn it.
NOTE: There are things you should NOT do with your Glycerin. Remember, you should never dump it into a stream or down the drain. Glycerin will kill fish and other aqautic creatures due to its high BOD (Biological Oxygen Demand) rate.