When we think of algae, the first thing that comes to mind is pond scum – that slimy green stuff that clogs up drains and leaves a slimy green slush
on the surface of an otherwise clear and tranquil looking pond. The next thing that comes to mind are methods of removing it. After all, who would
want to cultivate ponds of that stinky green mush?
But how many of us realize that these simple, resilient, single-cell plants are so important to life on Earth in so many ways? In many eco-systems,
algae and diatoms form the foundation of the food chain. It provides food for lesser species, which are in turn eaten by progressively larger species
of animals all the way up to the top of the food chain.
East Asian cultures have been relying on algae as a food source for ages now. Seaweed, a macroalgae, has been the ingredient of many food products,
from sushi to jelly and even as the emulsifier in ice-cream. And for years now, health fanatics have extolled the virtues of nutritional supplements
containing microalgal strains that will increase the body’s health, vitality and energy.
Aside from being the foundation of various eco-systems’ food chain, a lesser known fact is that these simple plants provide between 50-70% of the
oxygen we all breathe and depend on. How is this possible, one might ask? We all know that forests are important features in the planet’s oxygen
cycle, but algae?
The answer lies in the fact that more than 70% of the Earth’s surface is covered in water. Most marine algae may be almost invisible to the naked
eye, but just because they are not as prominent as tropical rainforests or the evergreen forests of the northern latitudes, it does not mean they are
any less important.
Now, as we step into the dawn of a new millennia, our friends the algae may become more important to us than we realize. With fossil fuel reserves
continuously depleting, the search is on for a viable source of renewable energy. It is in our best interest to push for clean and green sources of
At the forefront of these renewable sources of energy are hydrogen fuel-cells and biodiesel technologies. Although hydrogen fuel is touted as the
energy source of choice, with water vapor as the only emission, currently the infrastructure for its widespread usage is not yet in place. That leaves
biodiesel as the next viable alternative.
The Misunderstood Diesel
When we think of diesel engines, the image that often comes to mind is that of large trucks and buses spewing a dirty black cloud from its exhausts.
But this is common misperception. Modern compression-ignition (diesel) engine are much cleaner than its polluting predecessors and is actually more
efficient than the best spark-ignition (gasoline) engine. Some 40% more efficient. Coupled with the fact that biodiesel fuels are fully compatible
with the modern diesel engines without the need for any modifications, clearly the best alternative fuel for the present would be biodiesel.
Critics to biodiesel often cite resource limitations as a dampening factor to the development of biodiesel alternatives. They say that the land needed
to grow biofuel crops would compete with land needed for food crops. They say it will compete for water and nutrients. This is certainly true for most
biodiesel crops. But this is where our friend the algae comes in. Since it grows in ponds and could possibly be cultivated at sea, land issues are out
of the way.
It has been estimated that the per unit area yield of oil from microalgae culture systems is as high as 19,000 to 76,000 liters per acre, per year.
That is between 7 to 31 times more productive, compared with the next best crop, palm oil at 2,400 liters per acre per year. Oil derived from algal
sources processes into biodiesel as easily as any other terrestrial crop.
As for nutrient problems, this is clearly a non-issue as algal cultivation systems can be tied in to many other processes, such as waste streams from
human or animal wastes to coal power plants, as a method of scrubbing the carbon dioxide emissions.
The only difficulty present with algal cultivation systems is finding the right strain with a high lipid content that grows fast and a cost-effective
cultivation method that best suits the strain selected. A lot of research and development is currently underway to overcome this obstacle, but the
future looks promising.
Into the Future
When the time comes and hydrogen fuel becomes the alternative energy source of choice, our friend the algae may still provide us with the answer. As
early as 1939 scientists discovered a strain of algae that sometimes switches production from oxygen to hydrogen. They found that by depriving the
algae of sulfur, normal photosynthesis within the plant would be disrupted and it would start producing hydrogen.
Clearly, algae are more important and useful than we give it credit. Not only do we owe much of our oxygen supply to it, these amazing plants may
someday provide us with another reason for our dependence on them – as a source of fuel. So the next time you see a patch of green slime stuck to
the wall of drainage ditches, don’t simply dismiss it. We depend on them more than they depend on us.
Hall, J. (2004) Ecology.com: The Most Important Organism in the World
Wikipedia (2006) Wikipedia.com: Algae Culture
Bengston, R. (2005) American Energy Independence: Biodiesel
Shehan, J., Dunahay, T., Benemann, J., and Roessler, P. (1998) A Look Back at the U.S. Department of Energy’s Aquatic Culture Program –
Biodiesel From Algae
pp. 3-4, pp. 248-251. www1.eere.energy.gov...
Briggs, M. (2004) UNH Biodiesel Group: Widescale Biodiesel Production From Algae
Originally posted at: www.xanga.com...
[edit on 3-18-2006 by Valhall]