Recently, an increasing interest in biodiesel has spread all over the world but, what is biodiesel, exactly? Biodiesel is a clean-burning alternative to petroleum-based diesel fuel made from renewable resources and totally biodegradable and non-toxic. Currently it is widely used in Europe
as fuel or fuel additive for most diesel internal combustion engines and turbine engines, and it is also available in the United States and Asia, as well as in Canada, where it is in its early stages of development.
Biodiesel is derived mainly from the likes of soybean and other oils, such virgin and recycled vegetable oils derived from crops such as canola, corn and sunflowers and animal fats or spent cooking greases, although it may be obtained from ethanol. Soy-based fuel is the most common used
biodiesel in its pure form or mixed with a petroleum-based diesel as an additive to improve the otherwise low lubricity of pure ultra low sulfur petrodiesel fuel.
Being environmentally safe and low polluting, the fuel is prepared by the reaction of fat or oil with alcohol under alkaline conditions. Chemically speaking, it comprises a mix of mono-alkyl esters of long chain fatty acids. After processing the oils, biodiesel has combustion properties
very similar to those of petroleum diesel, and can replace it in most current uses.
This fuel is also important from the Economic point of view, considered as one of the possible candidates to replace petrodiesel as the world's primary transport energy source thanks to its renewable condition and the fact that it can be transported and sold using today's infrastructure
instead of old fossil fuels ducts. In fact, it is available to consumers in a growing number of fuel stations, but still makes up a small percentage of fuel sold.
There are also a growing number of large transport fleets using some proportion of biodiesel in their fuel because with a flash point of 150°C, it is not as readily ignited as petroleum diesel which ignites at 64ºC, far less so than the explosively combustible gasoline which
ignites at -45°C. This way a vehicle fueled only by biodiesel is far safer in an accident.
Biodiesel has been classified as a non-flammable liquid by the OSHA, although as with most fuels, it may burn if heated to a high enough temperature, but significantly reduced in toxic and other emissions when burned as a fuel.