Biofuel
Biofuel
is solid, liquid or gaseous fuel obtained from plant or waste biomass as
opposed to fossil fuels (coal, petroleum or natural gas). Biofuels are burned
to produce heat or electricity. Types of biofuels include “first-generation”
biofuels, which use sugar, plant starch, vegetable oil, or animal fats to
produce biodiesel, bioethanol, biogas (see “Methane Digestion”), and syngas
(from pyrolysis and gasification of biomass, as opposed to coal) (UN
2007). “Second-generation” biofuels use
biomass-to-liquid technology to extract fuel from non-food sources like woody
waste materials or inedible energy crops (Pu et al. 2007, Inderwildi and King
2009) (see “Cellulosic Ethanol”). Third-generation” biofuel refers to fuels
refined from the oil of living farmed algae (see “Algal Biodiesel”). Biofuels
are, in theory, more sustainable than fossil fuels because the carbon they burn
(e.g. wood) is newly removed from the carbon cycle, versus coal or oil that had
been sequestered more or less indefinitely. Replacement of fossil fuels with
biofuels can result in reduced GHG: relative to the fossil
fuels they displace, GHG emissions are reduced 41 percent by production and
combustion of biodiesel (Hill et al. 2006). There are currently 10 biodiesel fueling stations in the
North Coast (two in Humboldt County, four each in Mendocino and Sonoma Counties
(www.cleancarmaps.com). See “Biomass”.
Citations:
Hill, J., E. Nelson, D. Tilman, S. Polaski, and D. Tiffany. 2006. Environmental, economic and energetic costs and benefits of biodiesel and ethanol biofuels.
Inderwildi , R.O. and D.A. King. 2009. Quo vadis biofuels. Energy & Environmental Science 2: 343.
United Nations (UN). 2007. Sustainable Bioenergy: A Framework for Decision Makers. 64 pages. http://esa.un.org/un-energy/pdf/susdev.Biofuels.FAO.pdf
Pu, Y., D. Zhang, P.M. Singh, and A.J. Raguskas. 2007. The new forestry biofuels sector. Biofuels, Bioproducts and Biorefining 2(1): 58-73.
