What is the glycerin layer (aka “glycerin“)?
Glycerin is the byproduct left over after the biodiesel reaction process is complete.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. (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.
1. Put it in demethylating equipment. 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.
2. Put your glycerin and your wash water into the equipment
3. Make soap.
4. Feed your glycerol to cattle.
5. 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.
6. Use it as a composting agent.
7. Use it as a dust suppressant.
8. 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.