Algae For the Third Generation Biofuel

Studies show that current generation of biofuels using food crops like canola, corn, soybean, sugar, grain and rapeseed have driven up food prices and aggravated deforestation. Measurements of emissions from the burning of biofuels derived from these food crops have been found to produce more greenhouse gas emissions than they save.

In the quest for fossil fuel alternatives to provide greener energy, researchers are excited over the vast potential offered by algae as a source of biofuel. Most oil in the world today was formed by decayed algae dating back millions of years ago. This process can be replicated to give us a cleaner energy. The inputs are sunlight, together with water and carbon dioxide during the process of photosynthesis. The output is oil.

Algae can double their mass several times a day and produce at least 15 times more oil per acre than alternatives such as rapeseed, palms, soybeans, or jatropha. They can produce 5,000 to 50,000 gallons per acre, per year which is 7 to 30 times greater than the next best crop, Chinese tallow (699 gallons).

Research in algae biofuel dates back to the 1950s where algae cultivation was carried out under natural condition which gave low oil yield of 1% by weight of the algae, to be compared with an increased yield of 40% in wastewater medium. Hypothetically, algae grow even better in media with high concentration of carbon dioxide (the main greenhouse gas) and organic material like wastewater, executing concurrently a much welcomed task of turning wastes into resources.

(Pic show algae cultivation under lab conditions )

Algae can also grow in salt water, freshwater or even contaminated water, at sea or in ponds, and on marginal land not suitable for food production. On marginal land and in brackish water, the comparison can even reach 30-100 times the oil yield of soybeans. In wastewater, medium needs to be treated in advance via anaerobic digestion to eliminate algae contamination.

The biomass left-over from oil-pressing can either be fed to cattle as a protein supplement, or fermented into ethanol or produce butanol. In most gasoline engines, butanol can be used in place of gasoline with no modifications. In several tests, butanol consumption is similar to that of gasoline, and when blended with gasoline, provides better performance and corrosion resistance than that of ethanol or E85

They are technical problems facing the algae cultivation, one being the draining of the water medium to harvest algae. One such solution can be to grow freshwater algae in nutrient-rich wastewater inside semi-permeable plastic membranes. The ocean salinity will draw the freshwater out, but retaining the plants and nutrients. The membranes prevent saltwater from getting inside and killing the plants, while ocean waves keep the algae mixed and healthy. The process simultaneously treats the sewage water, which is then released into the ocean.

Algae can be cultivated in an open pond system or a closed loop system. Open pond system normally uses monoculture, whereby the whole culture may be exposed to risks of temperature fluctuations and invasion of external algae species and bacteria.

In the closed loop system, choice species of algae are grown in thin-walled polyethylene tubing, called photobioreactors ( PBR ), and exposed to sunlight. This closed system eliminates problem of air-borne bacterial contamination or contagious infection. However, running a PBR is more difficult and more costly.

For economically viable biodiesel production from algae, the strategies include:

1.	Choice of an algae strain with a high lipid (oil) content, AND a high growth rate, e.g. the less complex microalgae of diatoms and cyanobacteria
2.	Algae strain that can resist temperature fluctuations and invasion of other algae species
2.	Design of a system that enables easy harvest of algae
3.	Set up of a cost-effective cultivation system (i.e., type of photobioreactor ) that is best suited to that strain.
4.	Provision of an optimum medium with high carbon dioxide concentration and its location, for example, within close proximity of coal power plants or sewage treatment facilities (to reduce raw material and transportation cost too)

Feasibility studies of different nature, either through different grains or microalgae, macroalgae ( e.g. seaweeds ), media and nutrients, are being conducted by many institutions, to name but a few are: International University Bremen, The International Research Consortium on Continental Margins, Woods Hole Oceanographic Institution and the Harbor Branch Oceanographic Institution, the Department of Biological and Agricultural Engineering of the University of Georgia

First US Flight on Biofuel: Straitstimes Jan 08, 2009

Airlines have been experimenting with alternative fuels as a way to reduce carbon dioxide emissions and lower fuel bills, which hammered carriers in the first part of 2008 when oil prices spiked.

Continental Airlines became the first US commercial carrier to conduct a demonstration flight powered in part by alternative fuels derived from algae and jatropha plants.

Continental chairman and chief executive Larry Kellner said the goal was to analyze technical aspects of using biofuels, including effects on the plane's mechanical systems. The algae/jatropha fuel was praised for having a low flash point and sufficiently low freezing point, issues that have been problematic for other bio-fuels.

References and related news:

About Oilgae: Oilgae.com
Biodiesel Backers Seek Same Boost As Ethanol: Minnesota.publicradio.org/2008/03/12
Bill Gates Invest in Third Generation Fuel from Algae: Carbonmanagers Sept 29, 2008

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