Feature
The University has received approval to burn oat hulls, a renewable fuel, at its Southeast Steam Plant.
Oat hulls approved for University steam plant
MPCA allows the U to burn oat hulls, a renewable fuel, in Twin Cities steam plant
By Deane Morrison
In a move the University has awaited for three years, the
Minnesota Pollution Control Agency (MPCA) on February 17 approved
the University's request to burn biomass--specifically oat
hulls--at its Southeast Steam Plant. Burning a projected 25,000
tons a year of oat hulls could save an estimated $2 million of the
forecasted $16.3 million cost of heating the Twin Cities campus
during this fiscal year, says Jerome Malmquist, the University's
director of energy management.
Renewable energy at the
University
The oat hull project is just one University effort to reduce its
dependence on fossil fuels and speed the advent of energy
technologies that reduce or eliminate greenhouse gas emissions. In
2004 the University
joined the Chicago Climate Exchange, a pilot program to
encourage reductions in greenhouse gas emissions in the United
States, Canada and Mexico.
Last year, the University launched an ambitious program at
its West Central Research and Outreach Center in Morris to supply
wind power to the Morris campus and support research on new
technologies based on biomass and conversion of wind power to
electricity, among other projects.
Under the aegis of the President's Initiative on the Environment
and Renewable Energy, numerous faculty-led projects are under way.
Perhaps most famous is the invention by Lanny Schmidt, Regents
Professor of Chemical Engineering and Materials Science, of a way
to generate
hydrogen from ethanol. To browse all the projects, click
here or
here.
The University currently produces 70 percent of its steam from
natural gas (and some wood) and the remainder mostly from coal.
Natural gas cost about $6.25 per million Btu (one million Btu is
abbreviated "MMBtu") last fiscal year, but in the wake of Hurricane
Katrina prices shot up to nearly $15 per MMBtu. The price has
dropped somewhat, but not before pushing the University over its
energy budget. The heating bill for fiscal year 2007 is projected
at $20.7 million, so a $2 million annual saving would cut about 10
percent of the cost, Malmquist says. Oat hulls once cost only $1
per MMBtu, but Malmquist suspects the price will at least double.
Even so, it beats the cost of natural gas. Of the 2 million MMBtu
produced to heat the Minneapolis campus in a year, about 1.6
million come from gas. Malmquist envisions a 320,000 MMBtu
contribution from oat hulls, with the contribution from gas
dropping to 1.24 million MMBtu. It's just too bad there aren't any
oat hulls available at the moment. The University had hoped to
obtain the hulls from General Mills, which husks oats destined for
cereal boxes at a plant in Fridley. But the company could not hold
onto its growing supply of hulls, so it signed a contract with U.S.
Steel to send them to fuel that company's facilities on the Iron
Range. The University may receive some surplus oat hulls in August
or September, and a permanent supply is being sought for the
future. Quaker Oats, the other major producer of oat hulls,
supplies the University of Iowa. The University of Minnesota is
looking into all possibilities for acquiring oat hulls and is also
considering surplus seed corn as a future fuel, according to
Malmquist. Renewable biomass fuels like oat hulls have some
drawbacks, but "they're still a huge improvement over fossiil
fuels," Malmquist says. "They drastically reduce greenhouse gas
emissions, but they do produce minor increases in emissions of
particulate matter, nitrogen oxides and sulfur oxides." If oat
hulls do come to the steam plant, they will replace some of the
natural gas the plant now uses. But they will never replace all of
it, nor the coal. Boilers are finicky, says Malmquist; with today's
technology, hulls can only be burned burned in conjunction with
coal. "Without a fuel like coal, oat hulls could ruin the boiler,"
he explains. "Biomass contains silica, and that can form glass. If
glass coats the tubes in the boiler, it will insulate the water in
the tubes from the heat." Therefore, it will be harder to turn the
water into steam.