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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 three places: a Chinese place, a donut shop and a Breakfast cafe (they all share the same 2 oil barrels).
The oil is top notch and 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 above). My oil usually requires 4-5 grams of
lye per liter of oil. I then mix the lye with 6 liters of methanol for 30 liters of oil. I get my methanol at the local
race track and store it in a 35 gallon barrel. 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. 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 and soap residues 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 100,000 miles
on my Jetta using biodiesel that is produced without washing and I have had no problems.
Final Storage and Use:
When the biodiesel is filtered, I store it in standard
5 gallon diesel containers available at most hardware stores. These make putting the biodiesel in the car's fuel tank fairly
easy. If you intend to make large quantities of biodiesel, consider using a 55 gallon drum and use a 12 volt diesel rated
pump to move the biodiesel from the drum to the car. These pumps are readily available and some even come with meters so the
you know exactly how much biodiesel you have pumped. Biodiesel can be run in concentrations from B2 (2% biodiesel, 98% diesel)
up to B100 (100% biodiesel). High concentrations of biodiesel (B40 and up) are more prone to gelling at low temperatures so
some caution and antigelling agents should be used during cold weather. I currently use any where from B20-B80+ in my Jetta
and in my Jeep Grand Cherokee.
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