The Safe Biodiesel Guide
Biodiesel is a clean-burning and renewable source of fuel made from vegetable oils or animal fats. Far from being an inferior biofuel, biodiesel is better both for your car engine and the environment than fossil-based fuels such as petrol or petro-diesel (regular diesel). And with unpredictable prices at the pumps, many people are turning to either making biodiesel or purchasing it from suppliers. With the former option, making biodiesel safely should be a priority. And with the latter, finding a biodiesel supplier near enough for its use to become economical can often prove difficult; however, a list of suppliers can usually be found by searching online.
Making biodiesel is nothing new. One Rudolf Diesel, the inventor of the diesel engine, showed interest in using vegetable oil (peanut oil) to run his engine. Even then the advantages for the environment and agriculture were clear to this genius. It was only after his controversial death that the petroleum industry capitalised on his invention by naming one of their by-products of petroleum-distillation diesel fuel (petro-diesel). This is how the polluting diesel fuel we know today became the common fuel for the diesel engine, and the more environmentally friendly vegetable oil fuel was mostly forgotten - until now. And these days, environmentally friendly fuels are more important than ever.
But first let us take a step backwards. If you are concerned about the environment and the price of fuel, there are actually three ways to run a diesel engine using vegetable oil:
- Use the vegetable oil just as it is (don't - please read below first!);
- Mix it with paraffin or petro-diesel or solvents;
- Convert the oil to biodiesel (transesterification).
1. Vegetable Oil. Vegetable oil is roughly five times more viscous or thicker than regular diesel. As a result a diesel engine would need to be modified to cope with this increased viscosity to ensure the oil flows freely through the fuel system into the combustion chamber. This can be accomplished either by pre-heating and so thinning the oil before it enters the injectors, or by installing a double tank system where the car is run on normal diesel until warm and then switched over to biodiesel. Another problem can be that oil has different chemical properties and combustion characteristics from the fuel that most diesel engines are designed to use. This can be especially problematic in newer, more precisely tuned cars.
2. Blending. Mixing or blending the oil with other fuels or solvents will also lower its viscosity. When mixing with petro-diesel this should be limited to 20% oil / 80% diesel, but this method isn't ideal environmentally as it still involves using a fossil-based fuel. And as for mixing with solvents such as white spirit or paint thinner, this is highly experimental and not recommended because performance and long-term effect on engine wear are both unknown quantities.
3. Making Biodiesel. For many people, making biodiesel is becoming the preferred option because biodiesel will work in any diesel engine, meaning that no modifications are required whatsoever. Biodiesel has better cold weather properties than vegetable oil too (but less than petro-diesel), it is clean and safe, and has good lubrication properties for the engine. Production costs tend to vary but depend mostly upon whether new or used oil is being used. Used oil is the cheaper option (and is often available for free). The only downside is that used oil has to be processed first, which is relatively straightforward, or it can even be bought that way (which, however, would be subject to tax). Making biodiesel can be a satisfying release for many people.