Algae: Biofuel Of The Future?
Aug. 19, 2008 - ScienceDaily
In the world of alternative fuels, there may be nothing
greener than pond scum.
Environmental engineering professors
Andres Clarens (center) and Lisa Colosi (right)
have teamed up with commerce professor Mark White
to investigate how algae may offer the biofuel of
(Credit: Melissa Maki)
Algae are tiny biological factories that use photosynthesis
to transform carbon dioxide and sunlight into energy so
efficiently that they can double their weight several
times a day.
As part of the photosynthesis process algae produce oil
and can generate 15 times more oil per acre than other
plants used for biofuels, such as corn and switchgrass.
Algae can grow in salt water, freshwater or even contaminated
water, at sea or in ponds, and on land not suitable for
On top of those advantages, algae — at least in theory
— should grow even better when fed extra carbon dioxide
(the main greenhouse gas) and organic material like sewage.
If so, algae could produce biofuel while cleaning up other
"We have to prove these two things to show that we really
are getting a free lunch," said Lisa Colosi, a professor
of civil and environmental engineering who is part of
an interdisciplinary University of Virginia research team,
recently funded by a new U.Va. Collaborative Sustainable
Energy Seed Grant worth about $30,000.
With the grant, the team will try to determine exactly
how promising algae biofuel production can be by tweaking
the inputs of carbon dioxide and organic matter to increase
algae oil yields.
Scientific interest in producing fuel from algae has
been around since the 1950s, Colosi said. The U.S. Department
of Energy did pioneering research on it from 1978 to 1996.
Most previous and current research on algae biofuel, she
said, has used the algae in a manner similar to its natural
state — essentially letting it grow in water with just
the naturally occurring inputs of atmospheric carbon dioxide
and sunlight. This approach results in a rather low yield
of oil — about 1 percent by weight of the algae.
The U.Va. team hypothesizes that feeding the algae more
carbon dioxide and organic material could boost the oil
yield to as much as 40 percent by weight, Colosi said.
Proving that the algae can thrive with increased inputs
of either carbon dioxide or untreated sewage solids will
confirm its industrial ecology possibilities — to help
with wastewater treatment, where dealing with solids is
one of the most expensive challenges, or to reduce emissions
of carbon dioxide, such as coal power-plant flue gas,
which contains about 10 to 30 times as much carbon dioxide
as normal air.
"The main principle of industrial ecology is to try
and use our waste products to produce something of value,"
Research partner Mark White, a professor at the McIntire
School of Commerce, will help the team quantify the big-picture
environmental and economic benefits of algae biofuel compared
to soy-based biodiesel, under three different sets of
White will examine the economic benefits of algae fuel
if the nation instituted a carbon cap-and-trade system,
which would increase the monetary value of algae's ability
to dispose of carbon dioxide. He will also consider how
algae fuel economics would be impacted if there were increased
nitrogen regulations (since algae can also remove nitrogen
from air or water), or if oil prices rise to a prohibitive
The third team member is Andres Clarens, a professor
of civil and environmental engineering with expertise
in separating the oil produced by the algae.
The team will experiment on a very small scale — a few
liters of algae at a time. They will seek to optimize
the oil output by using a pragmatic engineering approach,
testing basic issues like whether it makes a difference
to grind up the organic material before feeding it to
Wastewater solids and algae, either dead or alive, are
on the menu. "We're looking at dumping the whole dinner
on top of them and seeing what happens," Colosi said.
Some of these pragmatic issues may have been tackled
already by the various private companies, including oil
industry giants Chevron and Shell, which are already researching
algae fuel, but a published scientific report on these
fundamentals will be a major benefit to other researchers
looking into algae biofuel.
Published evidence of improved algae oil output might
spur significant follow-up efforts by public and private
sectors, since the fundamentals of this technology are
so appealing, Colosi said. Research successes would also
open the door to larger grants from agencies like the
U.S. Department of Energy, and could be immediately applicable
to the handful of pilot-scale algae biofuel facilities
recently funded by Shell and start-up firms.