How is biodiesel produced?

How is biodiesel produced?  

Biodiesel, also referred to as biofuel, is made from vegetable oil derived from the transformation of seeds, a process known as “crushing“, as well as from the recovery of used oil. Any type of vegetable oil can be used to make biodiesel. In France, rapeseed oil constitutes the main oilseed used for producing biodiesel. Rapeseed provides a significant yield and is an important resource for certain pollinator species such as bees. Thanks to its deep roots, it also plays an important role in protecting the soil against erosion.

In terms of its manufacture, the oil is extracted from the seed, then it is blended with an alcohol, such as ethanol or methanol, and a catalyst, namely sodium or potassium hydroxide thus promoting the chemical reaction. This process entails an esterification that produces a vegetable oil methyl ester (VOME). This ester is an essential component of biodiesel marketed in France under the name of “diester” or “oleo100” depending on its origin and content.