Biodiesel -The lowdown
If you’ve been wondering what that biodiesel option was at your local petrol station but wasn’t sure if it was for you, here’s a brief breakdown of what it is. Biodiesel is a diesel equivalent renewable fuel that can be manufactured from algae, vegetable oils, animal fats or recycled restaurant greases and can be used in unmodified diesel engine vehicles – clever eh? It is also biodegradable and non-toxic. However, there has been concern over where the source plant matter used to produce the fuel comes from. Farming for fuel can have huge environmental effects and also impact the food markets.
How does it save CO2 emissions: Burning biodiesel is not much different in pollution terms to burning petrolium-based diesel. However, since it is produced from plants, carbon dioxide already in the atmosphere is absorbed by photosynthesis when the plants grow. Therefore, biodiesel’s overall CO2 emission are about 60% less when compared to producing and processing petroleum-based diesel. Most of the carbon dioxide emitted when burning biodiesel is simply recycling that which was absorbed by producing plant growth, so the net production of greenhouse gases is smaller.
[via wikipedia]
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In your car: Blends of 20 percent biodiesel with 80 percent petroleum diesel (termed B20) can generally be used in unmodified diesel engines. Biodiesel can also be used in its pure form (B100), but may require certain engine modifications to avoid maintenance and performance problems. Some vehicle manufacturers are positive about the use of biodiesel, citing lower engine wear as one of the benefits of this fuel. However, as biodiesel is a better solvent than standard diesel, removes deposits in the fuel lines, and this may cause blockages in the fuel injectors. For this reason, car manufacturers recommend that the fuel filter be changed a few months after switching to biodiesel (this part is often replaced anyway in regular servicing). Most manufacturers release lists of the cars that will run on 100% biodiesel.
WARNING: In the UK many car makers only maintain their engine warranties for use with maximum 5% biodiesel — blended in with 95% conventional diesel — although this position is generally considered to be overly cautious. Peugeot and Citroën are exceptions in that they have both recently announced that their HDI diesel engine can run on 30% biodiesel
