Biofuels

Biofuels, fuels derived from biomass, include principally bioethanol and biodiesel. Biomass is any organic matter derived from plants available on a renewable basis. Unlike petroleum-based fuels, biofuels are considered to be carbon neutral because the plants that are used to make biofuels absorb carbon dioxide as they grow and thus offset the carbon dioxide produced when they are processed and used, mainly in transportation. This entry discusses types of first- and second-generation biofuels.

First-generation biofuels are produced primarily from food crops such as corn and sugarcane for ethanol and soy beans and palm oil trees for biodiesel. They account currently for most of the total global supply of biofuels. Their environmental and economic sustainability has been increasingly questioned over concerns that they may displace food crops, ...