Thursday, May 21, 2009

Midwest Power Plants Looking at Natural Gas


By December 2013, the UW-Madison’s Charter Street heating plant will be off its diet of coal and may start digesting wood chips, if state lawmakers approve a $251 million project.

The project, which was detailed on Tuesday, calls for:

• Retiring three of the heating plant’s coal-burning boilers, installed in the 1950s, and replacing them with a natural-gas boiler.
Modifying the fourth coal-fired boiler to accommodate biomass and natural gas.

• Maintaining a fifth boiler, fueled by natural gas, as is.

• Designing and installing a new boiler, bigger than any of the others, to operate on biomass and natural gas.

The project is included in Gov. Jim Doyle’s biennial capital budget and will need approval from the Joint Finance Committee and the full Legislature.

The changes would eliminate the need for nearly 110,000 tons of coal a year, replacing that fuel with as much as 250,000 tons of biomass, such as waste wood and agricultural products. They also would decrease pollution and create a market for biomass in Wisconsin, state officials said.

"That’s really the fundamental change we’re going for here," said Andrew Moyer, executive assistant to Wisconsin Department of Administration Secretary Michael Morgan.

"It’s exactly the path that we need to be on," said Jennifer Feyerherm, director of the Sierra Club’s Wisconsin Clean Energy Campaign.

Wisconsin is one of the best states in the country for biofuel, said Alan Fish, UW-Madison associate vice chancellor for facilities planning and management. State forests are laden with waste wood and Wisconsin’s once-thriving paper industry has shrunk dramatically. Creating a market for wood chips or pellets of waste wood and plastic would create jobs and help the economy, Fish said.

At the same time, crops grown for fuel, like switchgrass, and agricultural waste such as corn stalks are abundant, he said.

The new boiler would use circulating fluidized bed combustion, in which jets of air swirl the fuel around like a tornado, as Fish put it. The technology makes it easier to use different types and amounts of biomass, and to mix it with natural gas, he said.

Fish said the system is most efficient with 80 percent biomass and 20 percent natural gas, but it will take a while for the biofuel market to get organized and supply that much product. "We think we can probably accommodate two trainloads of renewable fuels a day, at full capacity," Fish said. Currently, trains bring coal in about every other day, he said.

A proposed $20 million biomass research lab, could be built adjacent to the heating plant. It is not included in the Charter Street proposal.

The new boiler will nearly eliminate sulfur dioxide emissions from the Charter Street plant, and could reduce particulates enough to put Dane County back into compliance for that type of pollution, according to a study by Titus, a Milwaukee firm.

The Charter Street plant is the largest of three that provide steam for heat and for chilled air for UW campus buildings. The other two are Walnut Street and the West Campus power plant co-owned by Madison Gas & Electric. Both burn natural gas.

The Capitol heat and power plant, at Blair and Main streets, which uses about one-third coal, will be converted to all natural gas, in a separate $25 million project.

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