Used as a substitute for conventional petroleum-based diesel fuel, biodiesel is becoming well known as an additive or replacement to traditional vehicle fuels. It is created through a chemical reaction called transesterification that combines a variety of oils, including animal fats, vegetable oils, and even algae, with an alcohol (usually methanol or ethanol), and a chemical catalyst (potassium hydroxide or sodium hydroxide). Finished biodiesel can be blended with petrol diesel in a variety of ratios. Any blend with 30% (known as B30) or less of biodiesel can generally be used in vehicles without modifying the engines. Larger quantities of biodiesel will require changes to how a vehicle’s engine works.
The advantages of biodiesel over petroleum diesel are numerous. Most importantly biodiesel is:
There is some controversy surrounding the biodiesel industry. Given that, in many cases, commercially produced biodiesel is made from food crops and feed stocks thus question if the trade off between food and fuel is sustainable. Additionally, the production of biodiesel results in a somewhat toxic byproduct, though the end product itself is very stable and safe.
But don’t forget that biodiesel is just one kind of biofuel.