U of I
Research advances in conversion of wastes and algae to crude oil
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[April 18, 2013]
URBANA -- Yuanhui Zhang and Lance Schideman,
both professors in the University of Illinois Department of
Agricultural and Biological Engineering, have combined their
research efforts to develop an innovative system that uses swine
manure to produce biocrude oil, grow algal biomass, capture carbon,
purify wastewater and recycle nutrients.
Zhang has spent more than a decade researching the conversion of
swine manure and biomass into crude oil. Schideman has done
significant research in the area of integrated algal systems for
wastewater treatment and bioenergy production.
"We first convert swine manure into crude oil in a
hydrothermal liquefaction reactor," Schideman said. "There is a
very strong wastewater that comes off that process. It contains
nutrients that can be used to grow algae that simultaneously
clean the water. Lately, we've added low-cost, bioregenerable
adsorbents into the system that allow us to grow additional
bacterial biomass and further improve effluent water quality.
"Our recent research, a combination of experimental work and
some computer modeling, has shown that we can reuse the
nutrients multiple times and thus amplify biofuel production
from waste feedstocks," he explained. "If we start with a
particular waste stream that has 1 ton of volatile solids in it,
we might be able to produce 3, 5 or even 10 tons of algal and
bacterial biomass. This new biomass is then recycled back into
the biofuel production process," he continued. "It can also
clean the water, with the goal of making it suitable for
environmental discharge or reuse in some other application. So
we get more bioenergy and more clean water resources -- both
good things in the long run."
Schideman said they are also focusing on developing markets
for the downstream products of the biocrude oil.
"This crude oil is similar to, but not exactly like
petroleum," he said. "It generally has higher oxygen and higher
nitrogen content than traditional petroleum, but lower sulfur
content. Some of those things are positive, some are negative,
but regardless, they're different. We have to understand those
differences in order to make the new materials compatible with
Schideman said that in the near term, "bridge" markets are
likely needed to begin using biocrude oil products on a smaller
scale than current petroleum refineries.
"Refineries need hundreds of thousands of barrels of material
each day," he said. "It can be a chicken-and-egg kind of
question. We have material, but not that much. And you don't
want to build or modify a refinery unless you have more
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Schideman said one bridge market to consider is blending light
fractions of the oil into existing fuels.
"Right now, your gasoline has a certain amount of ethanol mixed
in it," he said. "We are looking at other blending arrangements
where light fractions of this oil could go directly into an existing
Schideman noted that the heavy fraction can potentially be used
in asphalt-like products.
"Innoventor, an engineering and design firm near St. Louis,
licensed some of Professor Zhang's earlier work and converted animal
waste into a bio-oil product used in pavements," he said. "They made
an asphaltic binder and paved a 500-foot stretch of road to Six
Flags St. Louis. Now they're monitoring wear and tear on the road to
see if it performs as well as conventional pavement."
Schideman acknowledged that while they are making important
advances in their research, there is also a need to expand
collaborations, and he noted work with other researchers at the
Illinois Sustainable Technology Center and the Department of Civil
and Environmental Engineering.
"There is still significant work that needs to be done in order
to better understand the bio-oil products and their potential use in
different applications," he said. "We look forward to working with
others to accelerate the development of bio-oil products that can
provide sustainable alternatives to petroleum."
[Text from file received from the
University of Illinois College of Agricultural, Consumer and