- Itís a piece of piss
Thereís nothing we like more at SchNEWS towers
than a spot of DIY, be it a pint of homebrew or a free party.
But one piece of DIY that we reckon is up there with free parties
is home made diesel.
Yep, forget about handing your hard-earned coffers
over to the corrupt, greedy and killing corporations like Shell
and BP, take a squeezy bottle, a piece of sticky backed plastic
and make your own biodiesel. No seriously, biodiesel is a fuel
made from waste vegetable oil, of which there is literally tons
of the stuff being dumped in landfill sites up and down the country!
This otherwise waste is easily collected from chip shops and restaurants
and without too much hassle processed to make biodiesel that can
be used to run any diesel engine. Biodiesel, far from being an
inferior homemade product, is better for your engine than the
usual crappy fossil-based fuel that is helping to screw up the
environment and peopleís health. Biodiesel can be made in your
own backyard with little start up cost involved and works out
at about 30 pence per litre. Wanna know more? Then read on.
Letís first rewind and go back to the beginning
of the 1900s where Dr Rudolf Diesel has just invented the diesel
engine and is displaying it at the Paris exhibition. Sat right
there is the mother of all diesel engines happily chugging away
running on peanut oil! Rudolf had designed the Diesel engine to
be run a variety of fuels and during his Paris speech said, "the
diesel engine can be fed with vegetable oils and will help considerably
in the development of the agriculture of the countries which use
it." Sounds good for developing countries but not so good
for the petroleum industry. A few years later and Rudolf Dieselís
body is found drifting face down in the English Channel. After
holding secret talks with the UK navy about fitting diesel engines
into their submarine fleet Rudolf Diesel was killed by the French
to stop his diesel technology being fitted into submarines over
the world, nothing new there then! After Dieselís death the petroleum
industry capitalised on the diesel engine by naming one of their
crappy by-products of petroleum distillation Ďdiesel fuelí. Thatís
how dirty diesel fuel has come to be the fuel for diesel engines.
Fast-forward to the beginning of a brave new
millennium, one where oil is running out, the climate is fucked
and Biodiesel can save the world, well no but it can do its bit!
A few facts on biodiesel
Biodiesel is biodegradable and non-toxic. 100%
biodiesel is as biodegradable as sugar and less toxic than table
salt. It biodegrades up-to four times faster than petroleum diesel
fuel with up-to 98% biodegradation in three weeks. However, contrary
to a popular misconception, it stores indefinitely in completely
full, cool, dark containers. Compared to crappy fossil fuel diesel,
biodiesel has the following emissions characteristics:
100% reduction of net carbon dioxide
100% reduction of sulphur dioxide
40-60% reduction of soot emissions
10-50% reduction of carbon monoxide
a reduction of all polycyclic aromatic hydrocarbons
(PAHs) and specifically the reduction of the following carcinogenic
phenanthren by 97%
benxofloroanthen by 56%
benz-a-pyrene by 71%
aldehydes and aromatic compounds by 13%
5-10% reduction of nitrous oxide depending on
age and tuning of vehicle.
For every one ton of fossil fuel burnt, 3 tons
of CO2 is released into the atmosphere, biodiesel only releases
the CO2 that it has taken in while the plants it is made from
were growing, therefore there is no negative impact on the carbon
How to build a single tank biodiesel processor
Firstly though, we have to say that our biodiesel expert is not
longer involved in SchNEWS so we are not able to offer any advice
or further information on the subject further than what's here.
There are websites listed at the bottom of the page which contain
loads more info. Please don't email us asking questions about
biodiesel as we won't be able to help.
45 gallon drum.
1/2 or 3/4 Hp electric motor.
Two pulleys which produce 250 rpm and a max
of 750 rpm at mixer blade.
A belt for the above.
12 inch rolled steel rod.
Two steel shelf brackets (for the blade).
1 1/2 inch (38mm) brass ball valve.
A hinge and a spring to act as a belt tensioned.
2000-watt electric water heater element.
A water heater thermostat.
1 1/2 diameter piece of steel pipe * 3-5 inches
long with male threads on one end.
Assorted tat: angle iron, wood, screws etc.
- Cut a large opening (about half the top) in the top of the
- Drill 11/2-inch hole in the bottom of the drum.
- Weld the 1 1/2-diameter pipe in the hole at the bottom of the
- Attach the 1 1/2-inch brass ball valve to the pipe. This is
the drain valve.
- Drill a hole in the side of the drum at the bottom, same size
as the heater element.
- Fit the heater element making sure it is not touching the side
of the drum.
- Wire up the heater element.
- Attach one pulley to the rolled steel rod.
- Attach the other pulley to the spindle of the electric motor.
- Weld the propeller to the other end of the rolled steel rod
- Attach the rod, pulley and propeller assembly to one side of
- Weld a piece of angle iron across the top of the drum.
- Weld the unattached side of the hinge to the angle iron so the
propeller and rod assembly sits in the middle of the drum. The
hinge should swing the propeller and rod back and forth.
- Mount the electric motor on the side of the drum.
- Fit the belt to the pulleys and tighten by wedging a block of
wood into the hinge.
You also need to fashion a simple wooden measuring
stick with 10 litre increments.
Other bits and bobs
A hydrometer is a good piece of kit to have to measure the specific
gravity of the biodiesel. The specific gravity of biodiesel should
be between 0.860 and 0.900, usually 0.880. The specific gravity
of vegetable oil is 0.920 therefore the specific gravity of biodiesel
should be lower than the vegetable oil used to make the biodiesel.
How to make biodiesel
Every time you make a new batch of biodiesel using
old vegetable oil you have to find out the amount of reactants required
to get the correct reaction, this process is know as titration.
In addition to the above equipment you will also need the following
20 ml beaker
1500 ml beaker
500 ml beaker
A graduated eye dropper
Blender with a glass bowl.
Used cooking oil
Step 1 Titration: to determine the quantity
of catalyst required
- Measure 1 gram of Sodium Hydroxide onto a petri dish
- Measure 1 Lt. of distilled water into a 1500 ml beaker.
- Pour the 1 gram of Sodium Hydroxide into the 1 Lt. of distilled
- Label Ďdo not drink Sodium Hydroxideí
- Measure 10 ml of isopropyl alcohol into a 20ml beaker
- Dissolve 1ml of used vegetable oil into the isopropyl alcohol.
- Label oil/alcohol.
- Use the graduated eye dropper to drop 1 millilitre of Sodium
Hydroxide /water solution into the oil/alcohol solution
- After 1 millilitre of Sodium Hydroxide /water solution is
added check the pH
- Repeat steps 8&9 until the oil/alcohol reaches a pH of
between 8&9. The pH increase will usually occur suddenly.
Usually no more than 3 millilitres of Sodium Hydroxide /water
solution will need to be added.
- Use the following equation: ∑ the number of millilitres
of the Sodium Hydroxide/water solution dropped into the oil/alcohol
mixture = x ∑ (x+3.5)=N
∑ N= the number of grams of Sodium Hydroxide required to neutralise
and react 1 Litre of used vegetable oil.
∑ N will be between 4.5-6.5, but it can be
higher if the oil has been used for a long time.
Step 2. Measure the reactants
Measure the reactants in separate containers
1 Litre of filtered used oil into a 1500ml beaker
200 ml of methanol into a 500 ml beaker
N grams of Sodium Hydroxide onto a petri dish
Step 3. Dissolve the Sodium Hydroxide into the
The third step is to combine the methanol with
the Sodium Hydroxide to create sodium methoxide, an extremely strong
base. Once the Sodium Hydroxide has been dissolved in the methanol,
the sodium methoxide must be mixed with the vegetable oil straight
∑ Carefully pour the methanol into the blender,
any spills must be cleaned immediately with a water and vinegar
∑ Carefully pour the Sodium Hydroxide into
∑ Replace the lid of the blender and blend
on the lowest setting for 30 seconds, until the Sodium Hydroxide
has dissolved. Sodium methoxide has been produced and caution
must be exercised
Step 4. Mix the reactants
∑ Remove the lid of the blender keeping your
face well away from the top of the blender
∑ carefully pour the vegetable oil into the
∑ Place the lid on the blender and blend on
a medium/high setting for 15 minutes. If the bowl or the blender
motor get over hot switch off the blender and leave until cooled
down sufficiently to continue again.
Step 5. Allow the glycerine to settle
Settling takes about 8 hours but since 75% of the
separation occurs within the first hour after the reaction immediate
separation will be visible. Within 8 hours the glycerine will have
fallen to the bottom leaving a layer on top, this is methyl esters,
or more commonly referred to as biodiesel
Step 6. Separation
After blending the contents can either be transferred
into a 1500ml container with a stopcock or left in the blender for
at least 8 hours.
Step 7. Clean up
Store the leftover used vegetable oil in a dry
Clean all the equipment so it is ready to use again
Expose the glycerine to air and sunlight for 1
week and then use as soap.
Pour the biodiesel into your fuel tank and laugh
So there you have it, fuel from vegetable oil. Of course this is
only one method of making biodiesel, there are many recipes for
making biodiesel just take a look through the web sites at the end
of this article. Donít be fooled into thinking that biodiesel is
anything but a serious contender in the alternative fuels market,
throughout the world there are commercial processors being built
to supply a rapidly emerging market. The UK government however,
has chosen to ignore biodiesel, this is their mistake and something
we can capitalise on. Letís start making biodiesel and get production
down to the local small scale level with co-operatives and individuals
supplying all our needs while taking power away from the mega-corporations.
For more information on biodiesel check out www.planetfuels.co.uk
rather than emailing us
(please, you wouldn't believe how many people do email us) - we're
no experts, unfortunately. Alternatively the first book on the following
website (LILI: how to make biodiesel by Dan Carter & Jon Halle)
has been recommended to us: www.lowimpact.org/acatalog/books_biodiesel.html
The Low Impact
Living Initiative website also has other information and equipment
for biodiesel and other related topics.
Other Useful web sites: