Biodiesel is a fuel made from the triglycerides found in vegetable oils and animal fats. This includes a wide range of potential feedstocks from virgin materials like palm oil and soybean oil to wastes such as recycled cooking oil, grease trap oil, and waste animal fats. Through a chemical process known as "transesterification", the feedstocks are processed into biodiesel and by-products, including bio-heating oil, glycerin, fertilizer and a small amount of organic waste. Bio-heating oil is a heavy fraction produced by the distillation of the biodiesel. We re-use it in our plant to generate heat. Glycerin is a non-toxic byproduct that can be used in soaps and other commercial products.

Biodiesel has many advantages over petroleum-based diesel, foremost of which is significantly reduced greenhouse gas emissions. This reduction is dependent on the type of feedstock used. ASB's main feedstocks - used cooking oil and other waste oils - offer the maximum reduction in greenhouse gas emissions - 85 percent according to the UK's Department of Transport.

Biodiesel also contributes to better air quality by reducing certain other tailpipe emissions that cause pollution. The US Environmental Protection Agency has estimated that a blend of 20 percent biodiesel with 80 percent petroleum-based diesel reduces emissions of particulate matter (PM), unburned hydrocarbons (HC) and carbon monoxide (CO) by 10 percent, 21 percent and 11 percent respectively. Its impact on nitrogen oxide (NOx) emissions has been found to be negligible at low blend ratios.

Finally, pure biodiesel is non-toxic and biodegradable.

Further information about biodiesel can be found at the following useful sites:

UK Department for Transport
US Department of Energy
US National Biodiesel Board