How to dispose of glycerin from biodiesel

Biodiesel is made from treating cooking oil with methanol and potassium hydroxide. The resulting glycerine is then separated from the biodiesel and becomes a byproduct that needs to be disposed of. There is a market for pure glycerine, but the byproduct is toxic and must have the methanol removed before it can be handled. Methanol is a clear liquid that is toxic if inhaled, ingested or if it comes in contact with the skin. The glycerine cannot be used in any form until it has been removed.

Pour the glycerine into a pot. This pot should be used only once for the glycerine. Wear safety gear while you do this and stay in a well-ventilated area, preferably outside.

Bring the glycerine to a boil on a portable burner. The boiling point of glycerine is 66.1 degrees Celsius, so you must have a strong heat source. Let the glycerine boil for several hours until the methanol has boiled off. Once the methanol is gone, the glycerine is safer.

Compost the glycerine in a large compost pit. Stir the compost into dry vegetation and mix thoroughly. To decompose, air and bacteria must reach the glycerine. In a well-maintained compost pile, glycerine will decompose quickly. It will even add to the compost by acting as a compost activator, adding heat to the pile.

Place the glycerine in the pot and leave without a lid in a well-ventilated area. The glycerine should be in a location where children and pets won't be able to reach it.

Stir the glycerine occasionally over the next three or four weeks. The methanol will slowly evaporate from the glycerine. Once the methanol is gone you will be able to work with the glycerine.

Compost the glycerine as in the first section. Use a large compost pit and mix is thoroughly with dry vegetation.

Most recent