What is biodiesel?

Pure vegetable oil or a combination of diesel and vegetable oil is called biodiesel. In scientific terms, biodiesel consists of short chain alkyl esters. While vegetable oil is preferred, animal fats may also be used as a source of biodiesel. Vegetable oil undergoes transesterification to yield biodiesel. The commonly used biodiesel crops are soybean, canola, mustard seeds and cotton seeds.