Rachel Kuhaneck
Biodiesel from Algae
What is a Biofuel?
Demand for alternative fuel sources is rising
Biofuel = fuel (as wood or ethanol) composed of or produced from biological raw materials (Dictionary)
Aquatic Biofuels = biofuels produced from aquatic photosynthetic organisms (mainly algae) and organic
wastes of the fish industry. (FAO)
Algae as a Biofuel
All algae comprise of the following, in varying proportions: Proteins, Carbohydrates, Fats and Nucleic
Acids
Various algae contain different levels of oil.
It is this fatty acid (oil) that can be extracted and converted into biodiesel
Algae Cultivation
Open Pond: can be categorized into natural waters (lakes, lagoons, ponds) and artificial ponds or
containers.
Closed Pond: cover a pond or pool with a greenhouse.
Photobioreactors: closed equipment which provides a controlled environment and enables high
productivity of algae.
Generally, greater amounts of lipid have been found in photobioreactor grown algae vs. either pond
method.
CO2 applications in photobioreactors (Schaefer et al, 2009)
Algae has also been looked at for sequestration of CO2 from power plant emissions
Limiting factor is lighting condition—especially during winter and at night.
Additional lighting is then required, resulting in negative CO2 balance
If lighting is provided by another method than fossil fuel burning, could have potential.
Pros
Because biofuel essentially comes from plants and animals, the sources can be replenished through
farming and recycling.
Biodiesel has fewer emissions than standard diesel, is biodegradable, and is a renewable source of energy.
Cons
With current technology, is unknown whether it would be economically viable.
Therefore, much research is still needed to improve techniques for commercial use.
Only one car has been tested with specific fuel from algae, diesel fuel is diesel fuel.
Pittman J. K., et al 2011
Microalgae have been estimated to have higher biomass productivity than plant crops in terms of land
area required for cultivation, are predicted to have lower cost per yield, and have the potential to reduce
GHG emissions through the replacement of fossil fuels
A major requirement of wastewater treatment is the need to remove excess N and P which can otherwise
lead to eutrophication.
Major differences between wastewater nutrients and other growth media is the high concentration of
nutrients in (such as N and P), and the presence of toxins.
Municipal sewage treatment consists of a primary treatment phase (sedimentation of solid materials), a
secondary treatment phase (suspended and dissolved organic materials are removed), and a final tertiary
treatment phase (removal of many dissolved inorganic compounds including N and P) which is the
potential of microalgae in N and P removal.
It was concluded that a major factor in the poor environmental impact of algal biofuels was the demand
for CO2 and fertilizer as a nutrient source. This could potentially be offset via wastewater for nutrients
and power plants for CO2.
Research still needed in ways to harvest algae efficiently and cost effectively.
Resources
Biofuel. 2010. In Merriam-Webster Online Dictionary. Retrieved October 12, 2010 from
http://www.merriam-webster.com/dictionary/biofuel
Food and Agricultural Organization of the United Nations. 2010. Bioenergy: Aquatic Biofuels.
Retrieved October 12, 2010, from http://www.fao.org/bioenergy/52185/en/
How Stuff Works. 2010. How Biodiesel Works. Retrieved October 12, 2010, from
http://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/biodiesel2.htm
Oilgae. 2010. Biodiesel from Algae. Retrieved October 12, 2010, from
http://www.oilgae.com/algae/ap/ap.htm
Pittman J. K., Dean A. P., Osundeko O., 2011. The potential of sustainable algal biofuel
production using wastewater resources. Bioresource Technology, 102, 17–25.
Schaefer M., Behrendt F., Hammer T., 2010. Evaluation of strategies for the subsequent use of
CO2. Frontiers of Chemical Engineering in China, 4 (2), 172 - 183
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