Bio-diesel is an alternative fuel that is biodegradable and non-toxic. It is produced from vegetable oils like soybean, olive, and palm oils through a process of filtering, heating, mixing with methanol and an acid catalyst, and separating out glycerin. The process can be done at home with used cooking oil through several stages including mixing, heating, settling, washing, and filtering to produce a clear fuel. Producing one's own bio-diesel provides more sustainable energy and takes waste vegetable oil to fuel vehicles.

1. BIO-DIESEL
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2. What is Bio-Diesel?
• Bio-Diesel is a biodegradable and non-toxic alternative fuel
produced from new or used vegetable oil that is produced from
renewable vegetable resources, like: soy bean, olive, palm tree,
peanut, etc.
• And the best of all, It can be used in any Diesel engine without
modification.
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3. We can make our own Bio-Diesel?
• Anybody can make bio-diesel. It's easy and it's better than the
petro-diesel fuel. It's much cleaner, better for the environment
and better for health. If we make it from used cooking oil it's not
only cheap but you'll be recycling a troublesome waste product.
Here's how we can do it.
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4. First stage
1) Filter the oil;
2) Remove the water from the oil by heating the oil to 60
deg C, maintain the temperature for 15 minutes and
then put the oil into a settling tank for at least 24
hours. Make sure you never empty the settling tank
more than 90%;
3) Measure the volume of oil to be processed;
4) Heat the oil to 35 deg C to make sure that all solid fats
are melted;
5) Measure 0.08 litres of methanol (use only 99%+ pure)
for each litre of oil and add to the heated oil;
6) Mix for five minutes;
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5. First stage
7) For each litre of oil add 1 millilitre of 95% sulphuric acid;
8) Mix gently at low speed while keeping the temperature at
35 deg C for one hour, then stop heating;
9) Continue to stir the unheated mixture for another hour and
then stop stirring. Let the mixture sit for at least eight
hours;
10) In the meantime prepare the sodium methoxide: measure
0.12 litre of methanol for each litre of oil and weigh 3.1
grams (up to 3.5 grams if purity is in doubt) of sodium
hydroxide lye per litre of oil. Mix the sodium hydroxide lye
into the methanol until is completely dissolved;
11) After settling for eight hours, put half of the prepared
methoxide into the unheated mixture and mix for five
minutes;
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6. Second stage
12) Heat the mixture to 55 deg C and maintain for the
whole reaction;
13) Add the second half of the prepared sodium methoxide
to the heated mixture and start mixing at the same low
speed for about 1.5 to 2.5 hours. (note: take regular
samples in to a glass container and check if stays
yellow colour, when this colour is reached turn the heat
and mixer off);
14) Allow to settle for one hour;
15) Drain off the glycerine;
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7. Third stage “Washing”
16) Add one-third the volume of water as the amount of
biodiesel to be washed, and start the bubble-wash
(regular air pump) and let it bubble for 24 hours
minimum;
17) Remove the water and use ordinary litmus paper to
see the rough pH level (acidity/alkalinity). The end
result should be neutral (pH7).
18) Let the bio-diesel stand for about three weeks and
use only when it becomes crystal clear. If you want
quicker results, heat the bio-diesel to 45 deg C and
let it cool. (note: a deposit may form in the bottom
during settling, don't let it get in your fuel tank.)
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8. Examples of Bio-Diesel processors
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9. Conclusion
• “As a society, we will use up our fossil fuels much sooner than we
will transcend towards a healthy raw food diet; fried foods and
waste vegetable oil are not a scarcity. There is also a huge
transformation that happens when you are in control of your own
fuel and energy needs. Being able to harness ones own energy in
a sustainable manner is one of the best things we can do to
support our fragile planet.”
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10. End
Work elaborated by:
• Sérgio Paulo Lopes da Rocha
Engineering of Production and Industrial Maintenance - 1º Year
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