The US Department of Energy’s Office of Energy Efficiency and Renewable Energy provided the following description of biofuels in the “Biomass FAQs” section of its website, www.eere.energy.gov (accessed July 8, 2008):
“Biofuels are any fuel derived from biomass. Agricultural products specifically grown for conversion to biofuels include corn and soybeans. R&D [research and development] is currently being conducted to improve the conversion of non-grain crops, such as switchgrass and a variety of woody crops, to biofuels.
The energy in biomass can be accessed by turning the raw materials of the feedstock, such as starch and cellulose, into a usable form. Transportation fuels are made from biomass through biochemical or thermochemical processes. Known as biofuels, these include ethanol, methanol, biodiesel, biocrude, and methane…"
The Food and Agriculture Organization of the United Nations (FAO) wrote the following in its fact sheet “Knowledge on Bioenergy,” published on www.fao.org, (accessed July 9, 2008):
“Biofuels include solid, gas or liquid fuels. The latter account for less than 2% of road transport fuels worldwide. Future potential of biofuel development will remain low (current predictions amount to about 4 % in 2030) although doubling today's current proportion.
Current liquid biofuels include bioethanol - based on the fermentation of sugar and starch crops, and biodiesel - based on the transesterification of plant oil and animal fats. The derived ethyl or methyl esters can be used as a pure biodiesel or be blended with conventional diesel. Also pure vegetable oil is used as fuel for diesel engines.
Depending on agro-ecological and socio-economic context, feedstocks for bioethanol production include sugar beet, sugar cane and sweet sorghum as the most common sugar crops, with maize, potatoes and cereals the most common starch crops.
In temperate regions, rapeseed, corn or other cereals are used as feedstock. In tropical regions, cane sugar, palm oil, and, to a lesser degree, soybean and cassava are used. There is potential for sugar beets to be adapted to tropical regions for sugar production as well.
The main oil crops for biodiesel production include canola (rapeseed), palm and soybean, with complementary feedstock coming from animal fats and waste vegetable oils, and, at an experimental stage micro-algae.
First generation biofuels refer to those made from sugar, starch, vegetable oil, or animal fats using conventional technologies.
Second-generation biofuels are made from lignocellulosic biomass feedstocks using advanced technical processes and are expected to become viable over the next 5-10 years.”
The Intergovernmental Panel on Climate Change (IPCC) wrote in chapter five of its 2007 report titled “Mitigation of Climate Change,” published on www.ipcc.ch, that:
“The term biofuels describes fuel produced from biomass. A variety of techniques can be used to convert a variety of CO2 neutral biomass feedstocks into a variety of fuels. These fuels include carbon-containing liquids such as ethanol, methanol, biodiesel, di-methyl esters (DME) and Fischer-Tropsch liquids, as well as carbon-free hydrogen…
Biofuels can be used either ‘pure’ or as a blend with other automotive fuels [an example is E85, a blend of 15% gasoline and 85% ethanol]. There is a large interest in developing biofuel technologies, not only to reduce GHG emission but more so to decrease the enormous transport sector dependence on imported oil. There are two biofuels currently used in the world for transport purposes – ethanol and biodiesel…"