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These are the basic steps to making biodiesel at home. These are simply bare bones instructions however and you should consult
sources like the book: From the Fryer to the Fuel Tank, for complete and detailed instructions. If you want to make biodiesel
but do not want to assemble the necessary parts, several home scale biodiesel production set-ups are available commercially,
just check online or look at the links on the Biodiesel America web page (see above).
Steps for biodiesel production
Step one: The first step to making biodiesel is to put the clean, used vegetable oil into a suitable container. I put the
oil in this mixing vessel, it is a 15 gallon cone bottom tank with a drain on the bottom to drain off the waste glycerine
and the biodiesel. Currently I make around 7+ gallons (30 liters of oil plus 5 liters of methanol) at a time in this configuration
but I can easily make up to 10 gallons at a time. My oil comes from a Chinese food place and is top notch. It is pure Soy
oil and they change it about every two days. This produces some really nice biodiesel. Depending upon your supplier, you might
find that it is actually a mixture of vegetable oil and BEEF FAT. This mixture tends to thicken at temperatures below about
50 degrees F and will need to be heated before filtering and reaction. It will also require a second period of settling after
the glycerine separates. This second period of separation allows small amounts of unreacted beef fat to settle out before
the biodiesel is passed through the filter for final use.
Step two: The next step is to determine the correct amount of lye to use with your oil. This can be done through a titrating
process or through a simplier, small batch process (see Biodiesel America link below). My oil usually requires 4-5 grams of
lye per liter of oil. I then mix the lye with 5 liters of methanol for 30 liters of oil. I get my methanol at the local race
shop and store it in a 5 gallon gas container. This is highly volatile stuff and VERY poisonous if absorbed through the skin.
BE VERY CAREFUL, USE LATEX GLOVES AND EYE PROTECTION AND DO NOT BREATHE THE FUMES!
Step 3:The sodium meth-hydroxide is then added to the used oil. I use a chemical pump to circulate the oil/lye/methanol mixture.
This pump and its associated tubing can be seen on the first picture. the pump can be easily disconnected for cleaning and
draining of the glycerine. It is also handy for pumping the finished biodiesel into containers for filtering. I have tried
a number of variations on how to add the lye mixture to the oil and have come back to a simple one stage process...add all
of the lye mixture at once and then mix for 60 minutes.
Step 4: After the mixture settles for about 24 hours. I drain off the glycerine leaving the biodiesel behind. I do this
in several stages to allow all of the glycerine to make its way to the bottom of the cone shaped tank. I then strain the biodiesel
through a fryer filter. NOTE: If your reaction forms a gel instead of liquid biodiesel you are using either too much or too
little lye, lower or raise the amount of lye a bit at a time until you produce no gel in your small test batches. TO PREVENT
WASTING LARGE AMOUNTS OF OIL, DO NOT MAKE A LARGE BATCH UNTIL YOU CAN SUCCESSFULLY MAKE SMALL TEST BATCHES OF BIODIESEL (this
is a lesson I have discovered the hard, messy way).
Step Five: As the final step, I run the biodiesel through a standard fuel filter setup that I contructed. This is a
canister filter from NAPA but even an old fuel filter setup from an A1 VW diesel would work. I save some money by removing
and cleaning the filter with soap and water every two or three batches and letting it dry in the sun. Some people water
wash their biodiesel before using it. This process is necessary, some believe, to remove the excess methanol in the biodiesel.
I have found washing to be time consuming (may take a full week for water and biodiesel to seperate) and unnecessary. I
have over 60000 miles on my Jetta using biodiesel that was produced without washing and I have had no problems.
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