The use of biofuels is becoming more and more common because of both environmental and economical concerns. Several attempts have been made for the substitution of fossil fuels with other alternative fuels. An important feedstock for the production of biofuels fully adapted to modern engine technology is ester molecules derived from refined or crude vegetable oils and animal fats. Two distinct techniques have been applied for the transformation of the vegetable oil's esters into molecules compatible with petroleum diesel that is transesterification of ester molecules for the production of lighter esters by using an alcohol and hydrogenation of ester bonds for the production of linear hydrocarbons. The way both biofuels are produced is discussed in this work. Raw materials tested, production methods and systems investigated, feasibility of production of these fuels in plant and industrial scale and the main characteristics of the two fuels are included. WIREs Energy Environ 2014, 3:3–23. doi: 10.1002/wene.78This article is categorized under: Bioenergy > Science and Materials Energy and Development > Science and Materials