Skip to main content
Skip to navigation

Dec. 6, 2012 Volume 34, No. 15

Biomass boiler likely to reduce coal burning by more than 25 percent

Alternate text

POWERING UP Gregg Coffin, Power Plant superintendent, expects the biomass boiler to be at full capacity sometime in Feburary. The plant powers and heats more than 13 million square feet of campus buildings. Rob Hill photo


New boiler expected to be at full capacity by early February

After roughly four years of analysis and design, two years of construction and road closures, 150 contracted employees and $75 million of equipment and labor, Gregg Coffin will be relieved when MU’s new biomass boiler is operating at full capacity.

“In the course of a project, you’re always excited when you get close to the end,” said Coffin, the Power Plant superintendent. “It’s a relief to start seeing [contractors] leave and things get finished so we can work our way back to normal.”

He’s almost there.

In late November, the inside lining of the new 85-foot-tall boiler finished curing, allowing the plant to burn biomass. The boiler burns natural gas during the start-up phase, but Coffin hoped to be running solely on biomass sometime this month.

It’s an incremental process to bring the boiler to full capacity — workers add fuel, adjust the oxygen levels to calibrate the burn, add a little more fuel, recalibrate and so on. The ramping-up process will likely continue into February. At that point they’ll test to make sure they’re meeting the capacity, emissions and efficiency standards promised by the boiler manufacturer.  

The work is the final phase of a project started in 2007 when the university contemplated how to replace one of the power plant’s old and increasingly unreliable coal-fired boilers. A design team researched new boiler options and found that biomass was the best choice from both an ownership cost and emissions standpoint. 

The $75 million boiler is being financed primarily through bonds repaid from power plant revenue (the plant charges campus units for steam and electricity usage). 

With the new boiler, Coffin expects to reduce coal usage by more than 25 percent. The biomass boiler will use sustainably-sourced biomass, which will reduce the power plant’s emissions and shrink the university’s carbon footprint. He contends that the project is the biggest sustainable energy undertaking on any major American university campus.

Overall, the power plant can produce up to 66 megawatts of electricity and 1.1 million pounds of steam an hour — enough to power and heat more than 13 million square feet of campus buildings.

Each year, the boiler will use about 100,000 tons of biomass, delivered in a dozen or more semitrailer loads a day and stored in three large covered silos. 

At first, the biomass will be wood waste from mills, managed forestry and clearing for development. MU signed a six-year agreement with Foster Brothers Wood Products of Auxvasse, Mo., to supply biomass to the plant. 

But the boiler is flexible. It uses a “fluidized bed” — a layer of heated sand that bubbles like boiling water — that is able to ignite a host of fuels with a range of moisture contents. So if prices change to where other fuel sources — switchgrass, corn stover or other agricultural residues — become cheaper, the boiler fuel can follow the market. 

Cerry Klein, LaPierre Professor of Engineering, and Mizzou Advantage’s Sustainable Energy facilitator, said the new boiler will be a boon for campus research.

“I think it’s a tremendous asset,” Klein said. “Our plant scientists … will be able to do test burns in this boiler and see exactly what particulates come out based on different plants and how they genetically modify them, and also what burns better and what gives us a better return on BTU for our money. 

“That is an advantage to us, because in most places you can’t do that,” he said.

Coffin hopes researchers and students can develop a deep bench of back-up fuel sources that he can call on to get the best price. “It does make a good opportunity to partner with our academic community … to help them and them help us develop new sources of biofuel that can be used in the plant,” Coffin said. 

Shibu Jose, H.E. Garrett Professor of Agroforestry, researches how biomass production can be done sustainably and economically.

“There are all sorts of questions surrounding the logistics of producing the biomass and getting that biomass to the end user — or in this case the power plant,” Jose said, listing questions about how the biomass is produced, harvested, stored, transported and processed. “These are all topics we can research to make sure it’s the most cost-effective way of procuring the biomass for the bio boiler — and perhaps an economically viable opportunity for the landowners involved.”

Coffin hopes that operating a biomass boiler will help stoke the biomass fuel market and create local jobs. The power plant’s coal and natural gas come from out of state — Illinois, Texas and Oklahoma — but Foster Brothers is a Missouri company creating Missouri jobs. 

Coffin imagines area companies such as furniture makers and home builders expanding their businesses by selling wood waste to biomass suppliers. 

“I think that’s good for Missouri,” he said.

— Erik Potter