The four steps above are the simpliest way to make quality biodiesel. Remember this is only to give you an idea this is should not your only source before jumping into this project. Steps 3 and 4 above could be eliminated but without washing the fuel you will run into some major quality problems. The first step above is the processing of the oil the oil is heated to around 130 - 140 degree F this can be accomplished by an electric heating element, a propane burner, or perhaps a steam jacket. Once the oil is heated and the methanol and catalyst is mixed to form methoxide then you are ready to mix the oil this can be done with a paddle stirer or a pump recirulating the liquid from the bottom of the tank to the top. As the Methoxide is added be sure that if you used an electric heater it is off as methanol fumes around an element could cause an explosion and if you used a propane burner you should turn it off before you start handling methanol as you don't want a flame anywhere near methanol fumes or the liquid itsself. It is very important to respect all safety procedures! As the biodiesel and methoxide mix you are creating a mythl-ester which is the formal name for biodiesel. After the reaction takes place could which could take longer then an hour depending on how the liquids are mixed you are ready to turn everything off and let the mixture just sit in the tank.

That brings us to the next step above, after about 12 hours of the mix sitting in the tank with no agitation you will find a seperation. The heterogenous glycerin finds it's way to the bottom of the tank as it is heavier then the biodiesel that floats on top. This glycerin layer is the byproduct and is drained off of the bottom of the tank and disposed of. To learn more about what to do with the glycerin see our page on the byproducts of biodiesel. After the layer is removed from the tank you are left with biodiesel in the tank, this biodiesel is crude and most likely not of quality to pour into your engine. The picture below is of glycerin being drained from the bottom of the processor after settling.

 After the glycerin is removed there must be a process to clean and purify the mythl-esters. This can be done a number of ways a water wash can be performed which is pictured above in the process charts, a resin wash, or perhaps a bubble wash. The water wash is performed by misting water over the biodiesel, water is heavier than biodiesel so it will settle to the bottom much as the glycerin did. As this water settles out it passes through the biodiesel and picks up impurities such as residual catalyst, excess methanol and soaps. Once the water settles it is drained the same as the glycerin was, you will find that the wash water is white and soapy this is due to the impurities it removed from the biodiesel. This wash technique should be repeated untill rather clean and clear water is removed.

When the water settles to the bottom of the tank not all of the water settles some will become in solution with the biodiesel this yeilds a very milky appearance to the fuel. The fuel should be dried by heating it and allowing it to circulate for a few hours within the tank. This process relies on evaporation of water therefore you want the fuel to have the maximun surface area to the air. You will know when the drying is complete as the fuel will turn from the milky color to more of an amber tone. See the picture below which show the difference in the wet and dry biodiesel. The fuel to the far left is unwashed fuel, the middle beaker is the washed and dried fuel, and the right beaker is wet biodiesel. The layer of white in the far left beaker under the wet biodiesel is wash water.