The American Society for Testing and Materials
(ASTM) defines biodiesel fuel as monoalkyl esters of
long chain fatty acids derived from a renewable lipid
feedstock, such as vegetable oil or animal fat. ‘‘Bio’’
represents its renewable and biological source in contrast
to traditional petroleum-based diesel fuel; ‘‘diesel’’
refers to its use in diesel engines. As an alternative fuel,
biodiesel can be used in neat form or mixed with petroleum-
based diesel