What is biodiesel?
Biodiesel is alternative “Biofuel”, produced from biomass - a renewable resource. Pure biodiesel contains no petroleum, but it can be blended at any level with petroleum diesel to create a biodiesel blend. It can be used in diesel engines up to a 20% blend with little or no modifications. Higher blends, even pure biodiesel (100% biodiesel, or B100), may be able to be used in some engines. However, engine manufacturers are concerned about the impact of B100 on engine durability. Additionally, B100 is generally not suitable for use in low temperature conditions. Biodiesel is biodegradable, nontoxic, and essentially free of sulphur and aromatics.
How is biodiesel made?
The most common method for making biodiesel is through a chemical process called transesterification whereby the triglycerides obtained from plants (oil seed rape, soy bean, palm oil and many others) are reacted with methanol using an alkaline catalyst (usually NaOH). The process leaves behind two products -- methyl esters (the chemical name for biodiesel) and glycerol (also known as glycerin), a valuable byproduct traditionally usually sold to be used in soaps and other products.
Why should I use biodiesel?
Biodiesel is better for the environment because it is made from renewable resources. Biodiesel is significantly safer than petroleum-derived diesel: it has a higher flashpoint (150°C, compared to 77°C for petroleum diesel) and so does not ignite easily or produce explosive vapours. Emission benefits include less particulate matter (the soot associated with diesel engines), reduced levels of carbon monoxide and total hydrocarbons (the oxygen present in biodiesel improves combustion to carbon dioxide). These reductions increase as the amount of biodiesel blended into diesel fuel increases. The best emission reductions are seen with B100. Since it can be made domestically from renewable resources, its use decreases dependence on foreign oil, supports the agricultural sector and contributes to the domestic economy.