Green Energy: Algae-Based Biofuel Could Power Cars, Airplanes
In pursuit of environmentally friendly fossil fuel alternatives, corn, soybeans and palm oil have been converted into biofuels to power vehicles, factories and even the trains at Disneyland. Yet, these sources of energy, though far less polluting than petroleum or coal, occupy arable land, and may further jeopardize the global food supply.
Now, Israeli researchers have investigated the possibility of producing fuel from sea-harvested algae, and have found that a certain strain could provide an alternative fuel source, while restoring marine life in contaminated areas.
The appeal of algae is quite simple: The green layer that covers ponds and sea rocks can be converted into biofuel faster than conventional crops, such as corn and soy — without competing with food production. According to the US Department of Energy, the genetic diversity from the many varieties of algae presents researchers with “an incredible number of unique properties that can be harnessed to develop promising algal biofuel technologies.”
The algae possibility
Doctoral student Leor Korzen, under the direction of Prof. Avigdor Abelson from Tel Aviv University and Prof. Israel Alvaro from the National Institute of Oceanography, began growing sea lettuce in floating net baskets in the Mediterranean coast, just north of Tel Aviv. After each harvest (a cycle of 1-10 days), the team collected the sea lettuce to convert it into fuel. To expedite the process, the researchers applied ultrasonic frequencies greater than 20 kHz to the algae in order to quickly break down its complex sugars into glucose, which they then fermented into bioethanol.
The specific strain of algae they harvested (Ulva) was not only a more efficient producer of biofuel compared to other algae varieties, but when grown downstream from a fish colony, it grew 27-40 times faster than when it was harvested upstream.
Perhaps to their surprise, the symbiosis between algae and fish goes both ways: Algae serve successfully as a bio-filter for contaminated water. In this experiment, sea lettuce released nutrients back into the sea that had been crucial to marine life. “The concept of ecological sustainability in aquaculture refers to the maximization of internal feedback (e.g. recycling) within a culture system,” Korzen tells NoCamels.
Is Algae fuel scalable?
Algae biofuel, like many novel green energies, has yet to become economically viable on a massive scale. Some companies, including ExxonMobil, which recently pulled out of a $600 million joint venture to develop algae fuel, believe that commercial viability is more than 25 years away.
Yet, environmentalists maintain that the net positive effects of this green fuel could lead to faster commercialization. Compared to other biofuels, algae can be grown just about anywhere: On the sea shore, in a pond, even in photobioreactors, as pictured above. Moreover, algae can be harvested with run-off water contaminated with fertilizers, while the waste products from production can be used as a sufficient animal feed.
Such comparative advantages led the Japanese transportation and industry ministers to put algae high on their list of biofuels that could be used in jet engines, a goal they would like to achieve before the 2020 Tokyo Olympics. Since the announcement last summer, a handful of algae production companies have made headlines: Euglena in partnership with Chevron is testing its algae blends on Virgin Atlantic aircraft, while Toyota subsidiary Denso is developing algae-based diesel for motor vehicles.
If other governments follow with similar incentives, algae might just get off the water and into your car.
Photos: Eutrophication & Hypoxia