Biodiesel & It's Manufacture
Biodiesel is a fuel made from waste vegetable
oil, of which there is litreally 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 people's 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.
Background
Let's first rewind and go back to the beginning of the 1900s where Dr Rudolph 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! Rudolph 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 Rudolph Diesel's 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, Rudolph Diesel was killed by the French to stop his diesel technology being fitted into submarines over the world, nothing new there then! After Diesel's death the petroleum industry capitalised on the diesel engine by naming one of their by-products of petroleum distillation 'diesel fuel'. That's 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.
Biodiesel biodegrades up-to four times faster than petroleum diesel fuel with
up-to 98% biodegradation in three weeks. Compared to 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 PAHs:
* 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.
How to build a single tank biodiesel processor
Equipment required
* 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.
Assembly
1 Cut a large opening (about half the top) in the top of the steel drum.
2 Drill 11/2-inch hole in the bottom of the drum.
3 Weld the 1 1/2-diameter pipe in the hole at the bottom of the drum.
4 Attach the 1 1/2-inch brass ball valve to the pipe. This is the drain valve.
5 Drill a hole in the side of the drum at the bottom, same size as the heater
element.
6 Fit the heater element making sure it is not touching the side of the drum.
6 Wire up the heater element.
Chemical mixer
1 Attach one pulley to the rolled steel rod.
2 Attach the other pulley to the spindle of the electric motor.
3 Weld the propeller to the other end of the rolled steel rod (shelf brackets).
4 Attach the rod, pulley and propeller assembly to one side of the hinge.
5 Weld a piece of angle iron across the top of the drum.
6 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.
7 Mount the electric motor on the side of the drum.
8 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 equipment:
Petri dish
20 ml beaker
1500 ml beaker
500 ml beaker
Isopropyl alcohol
A graduated eye dropper
Litmus paper
Blender with a glass bowl.
Methanol
Used cooking oil
Sodium Hydroxide
Titration
Step 1 Titration: to determine the quantity of catalyst required
1. Measure 1 gram of Sodium Hydroxide onto a petri dish
2. Measure 1 ltr. of distilled water into a 1500 ml beaker.
3. Pour the 1 gram of Sodium Hydroxide into the 1 Ltr. of distilled water
4. Label 'do not drink Sodium Hydroxide'
5. Measure 10 ml of isopropyl alcohol into a 20ml beaker
6. Dissolve 1ml of used vegetable oil into the isopropyl alcohol.
7. Label oil/alcohol.
8. Use the graduated eye dropper to drop 1 millilitre of Sodium Hydroxide
/water solution into the oil/alcohol solution
9. After 1 millilitre of Sodium Hydroxide /water solution is added check the
pH
10. 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.
11. 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 Methanol
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 away.
- Carefully pour the methanol into the blender, any spills must be cleaned immediately with a water and vinegar solution.
- Carefully pour the Sodium Hydroxide into the blender
- 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 reactant
- Remove the lid of the blender keeping your face well away from the top of the blender
- carefully pour the vegetable oil into the blende
- 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 bio-diesel.
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 cool place
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!
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,
see below. Don't 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. Let's start making biodiesel
and get production down to the local small scale level with co-operatives
and individuals supplying all our needs instead of the mega-corporations.