Let algae do the dirty work.
at Rochester Institute of Technology (RIT) in Rochester, N.Y.,
are developing biodiesel from microalgae grown in wastewater. The project is
doubly “green” because algae consume nitrates and phosphates, and reduce
bacteria and toxins in the water. The end result – clean wastewater and stock
for a promising biofuel.
purified wastewater can be channeled back into receiving bodies of water at
treatment plants, while the biodiesel can fuel buses, construction vehicles and
farm equipment. Algae could replace diesel’s telltale black puffs of exhaust
with cleaner emissions low in the sulfur and particulates that accompany fossil
a lot of advantages. They are cheaper and faster to grow than corn, which
requires nutrient-rich soil, fertilizer and insecticide. Factor in the fuel
used to harvest and transport corn and ethanol starts to look complicated.
contrast, algae are much simpler organisms. They use photosynthesis to convert
sunlight into energy. They need only water – ponds or tanks to grow in – sunlight
and carbon dioxide.
“Algae – as
a renewable feedstock – grow a lot quicker than crops of corn or soybeans,”
says Eric Lannan, who is working on his master’s degree in mechanical
engineering at RIT. “We can start a new batch of algae about every seven days.
It’s a more continuous source that could offset 50 percent of our total gas use
for equipment that uses diesel.”
weather, however, is an issue for biodiesel fuels.
big drawback is that biodiesel does freeze at a higher temperature,” says Jeff
Lodge, associate professor of biological sciences at RIT. “It doesn’t matter
what kind of diesel fuel you have; if it gets too cold, the engine’s not
starting. It gels up. It’s possible to blend various types of biodiesel – algae
derived with soybeans or some other type – to generate a biodiesel with a more
favorable pour point that flows easily.”
graduate research in biofuels led him to Lodge’s biology lab. With the help of
chemistry major Emily Young, they isolated and extracted valuable fats, or
lipids, algae produce and yielded tiny amounts of a golden-colored biodiesel.
They are growing the alga strain Scenedesmus,
a single-cell organism, using wastewater from the Frank E. Van Lare Wastewater
Treatment Plant in Irondequoit,
to what we’re doing here,” Lodge says. “Algae will take out all the ammonia – 99
percent – 88 percent of the nitrate and 99 percent of the phosphate from the
wastewater – all those nutrients you worry about dumping into the receiving
water. In three to five days, pathogens are gone. We’ve got data to show that
the coliform counts are dramatically reduced below the level that’s allowed to
go out into Lake Ontario.”
Joseph Morelle, whose district includes Irondequoit,
applauds RIT’s initiative. “Innovations developed at great academic
institutions such as RIT will be key to solving many of the challenges we face,
from revitalizing the upstate economy to the creation of clean, renewable
energy sources for the future. Professor Lodge and Eric Lannan’s research
bridges the gap between cost efficiency and environmental conservation, and is
a perfect example of how old problems can yield to new and creative solutions.”
Lannan ramped up their algae production from 30 gallons of wastewater in a lab
at RIT to 100 gallons in a 4-foot-by-7-foot long tank at Environmental Energy
Technologies, an RIT spinoff. Lannan’s graduate thesis advisor Ali Ogut,
professor of mechanical engineering, is the company’s president and CTO. In the
spring, the researchers will build a mobile greenhouse at the Irondequoit wastewater treatment plant, and
scale up production to as much as 1,000 gallons of wastewater.
Biodiesel, located in Wayne
County, will purify the
lipids from the algae, and convert them into biodiesel for the RIT researchers.
Algae Clean Wastewater, Convert to Biodiesel
February 23, 2011