Maine college fires up biomass plant

By Luke Geiver | January 27, 2012

An $11.2 million biomass plant at Colby College in south central Maine is now on line and will provide heat, hot water and electricity for the campus. The facility is expected to save the school $1.5 million annually in heating costs.

“When we first began looking at biomass as a fuel the main purpose was to have a secondary source of fuel so we did not rely solely on oil,” said Patricia Whitney, director of the biomass plant. “But during the initial studies, we began to realize that there was a real opportunity to reduce our carbon footprint.”

The cogeneration facility features a gasification combustion system provided by Chiptec Wood Energy Systems, cyclonic dust collectors, and a $480,000 electrostatic precipitator that helps minimize pollutants. The two-stage gasification system is cleaner and more efficient than most systems, according to Whitney.

Cousineau Forest Products will supply the plant with wood chips, bark and treetops from a radius of roughly 50 miles, and during the periods of peak usage, the school estimates savings in heating costs could reach $250,000 monthly. Pizzagalli Construction created nearly 75 short-term jobs while building the plant, while the school’s long-term efforts to use biomass will create four to five permanent jobs in Maine’s forestry industry, according to Colby College. The biomass chips are delivered by a live bed truck and stored in an underground storage bin at the plant, according to Whitney.

“When working with an imprecise fuel, such as wood chips, there can be more opportunities for things to malfunction,” Whitney said, adding that the school has set the biomass plant up with two fully functional boilers. “This means, two boilers, two conveyors, two gasifiers, two disc screens, etc,” she said. Those disc screens also help resize the larger wood chips by rerouting the nonconforming chips to a resizer and grinder. To address the issue of ash, the school installed a conveyor that brings the ash into a collection container.

“Each time a challenge has presented itself, the design and construction teams have worked together to find a solution,” Whitney said. The project was finished ahead of schedule, initially slated for startup this year.