Production of biodiesel from vegetable oils

Biodiesel is produced by transesterification of triglycerides present in animal fat or vegetable oils, by displacing glycerine with a low molar mass alcohol. This resulting ester mixture has physico-chemical properties similar to those of petroleum diesel. This paper reviews the synthetic paths that lead to biodiesel by means of the catalytic transesterification of vegetable oils. Although methyl esters are at present the only ones produced at industrial scale, the use of ethanol, which can also be obtained from renewable resources, has been considered, since it would generate a cleaner and more biocompatible fuel.