Algal Biodiesel
Algal biodiesel is a type of biodiesel
fuel processed from oil produced by farmed algae (See “Biofuels”), as opposed
to recycled cooking oil or some other source. Also called “oilgae”, “algaeoleum” or “third-generation
biofuel,” this fledgling energy source holds promise as a petroleum fuel
replacement. In addition to biodiesel, algae might be used to produce (directly
or as a byproduct) the biofuels biobutanol, biogasoline, methane, ethanol, and
even bio-jet fuel (http://en.wikipedia.org/wiki/Algae_fuel), which can be used to produce heat
or electricity. Currently, much commercially produced biodiesel is made from food
crops however algal sources of biofuel could alleviate this situation (Chisti
2007). Algal biodiesel combustion produces the same carbon emissions as other biomass-based
biodiesels but can be produced much more efficiently. It is estimated that algae can produce 30
times more energy per acre than land crops such as soybeans (Hartman 2008). Algae
oil is biodegradable if spilled, can be made using ocean or wastewater, and is
relatively renewable; in contrast to most solid fuel biomass (e.g. switchgrass
or willow), the algae’s oils are harvested without destroying the living,
growing biomass. Algae’s photosynthetic activity removes carbon from the
atmosphere, so algae farms could also become a sink for greenhouse gases (see
“Carbon Sequestration”). Hurdles to algal fuel production include the large
infrastructure required to farm and process algae and concern about potential
use of genetic engineering to increase oilgae yields.
Use of biomass-derived fuel has the potential to reduce hydrocarbon and particulate emissions by an estimated 41 percent (Hill et al. 2007). Algal biodiesel may be the only viable method by which to produce enough automotive fuel to replace current world diesel usage (Sheehan et al. 1998). Algal biodiesel is in development (including in Siskiyou County, with the Oregon Institute of Technology) but is not yet commercially available.
Citations:
Chisti, Y. 2007. Biodiesel from microalgae beats ethanol. Trends in Biotechnology 26(3): 126-131.
Hartman, E. 2008. A promising oil alternative: algae energy. Washington Post. http://www.washingtonpost.com/wp-dyn/content/article/2008/01/03/AR2008010303907.html
Hill, J., E. Nelson, D. Tilman, S. Polaski, and D. Tiffany. 2006. Environmental, economic and energetic costs and benefits of biodiesel and ethanol biofuels.
Sheehan, J., T. Dunahay, J. Benemann, and P. Roessler. 1998. A Look Back at the US Department of Energy’s Aquatic Species Program - Biodiesel from Algae. National Renewable Energy Laboratory, Golden, Colorado.
