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| Making Biodiesel
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Biodiesel - How to make diesel fuel from used cooking oil
Biodiesel is a fuel that can be used directly in any diesel engine
generally without modification. It’s viscosity is twice that
of regular diesel fuel which means it is better at lubricating your
diesel engine than regular diesel. And... emissions are cut
dramatically vs using standard diesel fuel. You can buy Biodiesel
already made Or you can make it yourself using your own homemade
equipment.
One other option is to burn straight vegetable oil in your diesel
engine. To do this, you must do three things:
1) You must pre-heat your vegetable oil including the storage tank and
all feed lines,
2) You must start your engine using regular diesel or biodiesel, and
3) You must clean your system by burning only regular diesel or
biodiesel before shutting the engine off.
Here are the instructions on making your own biodiesel...
WARNING!!!!
Methanol is flammable and toxic. Do not let it touch your skin or get
in your eyes. Wear proper protective gloves, clothing, and eyewear at
all times. Same thing with ethanol. Lye is also very caustic - do not
allow it to touch your skin or clothing. When you mix the lye with the
alcohol, it creates an even more toxic substance and toxic fumes which
you should be very careful with - do not come into contact with it in
any way. Always be in a well ventilated area.
Also... you are 100% responsible for your own safety. The author is not
responsible in any way whatsoever for personal injury or damage to your
engine.
Let’s get started...
Here is a general description of how to make your own biodiesel fuel
using methanol, lye, and used cooking oil. This process is called
transesterification You can buy methanol from your local racetrack or
chemical supply store. You can buy granulated Red Devil lye (sodium
hydroxide) from your local grocery store or hardware store.
Make sure you filter the used cooking oil before using. Fry oil filters
can be purchased in any good restaurant supply store. The oil also must
be warmed up so it is not solid or lumpy or thick. You can use the sun
to heat the oil or some kind of water heating element or a electric or
gas burner of some sort. The ideal temperature is 120° F. If
you are using flames, remember that the methanol is extremely flammable
and you should turn your burner off before getting the methanol mixture
anywhere near it. Of course, this should all be done in a well
ventilated area too.
Hint...
To determine the amount of lye needed to start the transesterification
process, do a small test batch first.
You don’t want to mix up a large batch only to find out that
you did not use enough lye. Some used cooking oils may contain
different amounts of animal fats. The more animal fat in the vegetable
oil, the more lye you need to start the process. Start with just 1
liter of oil and 200 milliliters (1/5th of a liter) of methanol and 4.5
grams of lye. First, mix the lye in with the methanol until dissolved
(this creates sodium methoxide - very, very caustic - be careful). Then
mix the sodium methoxide with the vegetable oil and mix for 1 hour.
After mixing, let it settle for an hour or two and it should form two
distinct layers of biodiesel (top) and glycerin (bottom). If there are
not two distinct layers, repeat the whole process with 5.5 grams of
lye.
You can also perform what is called a titration...
Dissolve 1 gram of lye into one liter of distilled water and dissolve 1
milliliter of vegetable oil into 10 ml of isopropyl alcohol. Then drop
the diluted lye into the diluted vegetable oil one ml at a time. After
each ml, measure the pH of the diluted vegetable oil with litmus paper
or a pH meter. When the pH rises significantly, the free fatty acids
will be neutralized. The ideal pH is between 8 and 9. The number of ml
used will equal the number of extra grams of lye to use per liter of
vegetable oil (starting from 3.5 grams of lye).
So, let’s assume 5.5 grams of lye produced the desired
distinct two layers. We now want to scale it up to a 10 liter batch. So
we need 10 liters of used cooking oil, heated. 2 liters of methanol and
55 grams of lye. Mix the lye with the methanol until dissolved and then
pour the sodium methoxide mixture into the vegetable oil. Stir for one
hour.
The mixer can be a sump pump setup or some sort of mechanical electric
mixer like a paint mixer. After mixing, let it settle for 8 hours.
After settling, you can siphon or pump the biodiesel from the top.
After washing, run it through a Racor fuel filter before burning it in
your engine. The bottom part after settling is glycerin. A valve at the
bottom of your barrel or container is useful to drain off just the
glycerin. If you allow it to sit in the sun for a week to evaporate all
the methanol, you can use it as a degreaser or to clean your hands.
Washing your biodiesel...
After the above process is completed, you should
“wash” your biodiesel fuel to remove any residual
soaps suspended in your fuel. The easiest way to get rid of the
unwanted soap is to simply add water. The water will emulsify with the
glycerin soap and settle to the bottom. So to perform the wash, simply
spray an equal amount of water on top of your biodiesel and let it
settle to the bottom for 12 hours. Drain the water off the bottom of
your container with a valve and then repeat the process 2-3 times until
the water drained off is clear.
Heat your biodiesel up to 130° F for 20 minutes to evaporate
any residual water and you are literally ready to go! Remember to
filter it in a 5-10 micron filter before burning it in your engine.
Other ingredients...
Instead of using methanol, you can use ethanol. Ethanol is less toxic
than methanol and is considered a “greener” fuel
than methanol.
Ethanol is “grain alcohol” and is usually made from
corn which makes it a renewable fuel. Methanol is highly toxic and is
made from fossil fuels or it can be distilled from fermented wood.
That’s why it’s often called “wood
alcohol”. Also... you can use potassium hydroxide instead of
sodium hydroxide. I believe you’ll have to use 1.4 times as
much potassium hydroxide as sodium hydroxide though. Make sure you do
your “test batch” first!
Two more things....
1) What kind of engine do you need to use biodiesel... basically,
biodiesel will run in any diesel engine unmodified.
Biodiesel is a solvent, so if you put it in an old tank or use it with
a diesel engine that has been running regular diesel, it may clean and
dissolve some "residues" and then the residues will clog your fuel
filter. Changing the filter often when you first start using biodiesel
usually fixes this problem.
Usually, manufacturers warranties are not voided when biodiesel is
used, but check with your manufacturer to make sure. Sometimes a blend
like B20 is required (20% biodiesel). Now if you are running straight
vegetable oil (SVO), then you need to make modifications to pre-heat
the oil to increase it’s viscosity.
2) The only other problem you might have is with natural rubber gaskets
and hoses in vehicles made prior to 1992. The biodiesel may degrade
these types of rubber and they may need replacing after a while. Newer
engines have been modified (synthetic rubber) to stand up to the newer
blends of diesel fuel that have been in use since 1992 and these
engines will work fine with biodiese.
l
Bill Anderson
Network 6000, Inc.
author of "Electricity - Make it, Don't Buy it"
http://www.electricitybook.com
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