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The University's Southeast Steam Plant

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.