Maine Technology Asset Fund Awards $1.65 million to UMaine to Develop Grass Pellet Technology

Contact: Michael Bilodeau, 949-4177; Andrew Plant, 764-3361

A $1.65 million award from the Maine Technology Asset Fund will enable the University of Maine Biomass Engineered Fuel Project to prototype the Northeast’s first grass pellet production facility in Aroostook County.

“The grant will allow the University of Maine to better support the emerging solid biofuels industry in Maine and to demonstrate how agricultural energy crops can become an important part of the renewable energy mix in the state,” according to Michael Bilodeau, director of UMaine’s Process Development Center who co-directs the Biomass Engineered Fuel Project with UMaine Cooperative Extension Agriculture Educator Andrew Plant, who is based in Houlton.

“This research, development and commercialization collaboration between the University and the private sector has the potential to generate significant rural economic development activity.”

The Biomass Engineered Fuel Project links UMaine research and development with Maine farmers, energy consumers, companies and entrepreneurs to commercialize biomass fuel. In the next four years, the project will focus on the manufacturing efficiencies of converting energy crops from field to solid biofuel production, and the testing of that biofuel for performance, combustion efficiency and ultimate commercial potential.

The goal is to prototype a commercial-scale demonstration facility in Easton, Maine, backed by $7.7 million pledged in private investment to cover operating expenses. The grass pellets produced will be beta tested by several large commercial biomass boiler operations in the state, as well as the University of Maine at Presque Isle and the University of Maine at Fort Kent.

Several Maine companies have expressed interest in operating biofuel production facilities and licensing the technology.

Technical support for biomass appliance development, such as pellet burner replacements for oil-fired boilers and new biomass combustion units will be lead by UMaine’s Advanced Manufacturing Center, directed by John Belding. Ultimately, the pellet and boiler technology will be refined to find what works best in homes. With a mill in Maine for commercial demonstration, a grass pellet product for household sales could be possible in the next five years, according to the researchers.

The annual economic impact of a single commercial pellet mill in northern Maine is expected to be within $17 million and $23 million, according to Bilodeau and Plant. With potential for 25 pellet mills statewide, the overall economic impact is projected to be more than $500 million annually, with the potential to replace more than 100 million gallons of home heating oil each year.

Funding from the Maine Technology Asset Fund will stimulate greater private research and development of grass biofuels in the state, Plant says. “By initially relaxing the burden of risk for a company to explore the creation of this fuel, it will hopefully be the beginnings for other companies to explore how best to utilize it — new boiler development, new process development for an existing wood pellet industry, new market for farmers and potentially cheap heat for Mainers,” he says.

Maine has upward of 200,000 acres in which to produce perennial energy crops without displacing current food production, Plant says. If crop waste, such as straw from grain rotations, is included, the number of acres for energy crops can double.

As part of the Biomass Engineered Fuel Project, Aroostook County farmers are signing on to be “biomass growers,” planting energy crops as part of their rotations or on fallow ground they have around the farm.

For the past two years, Plant has been researching the use of perennial grasses or straw left from small grain rotations as solid fuel crops. The development and commercialization of such sustainable energy crops could give farmers another source of income and lower-cost energy.

To determine what perennial grasses will grow best in Maine, Plant started looking at species studied by the U.S. Department of Energy and Oak Ridge National Laboratory in the 1980s-1990s. Those grasses include the superstar of bioenergy crops — switchgrass — that produces dense pellets shown to have a 14:1 energy balance. In other words, for every unit of energy it takes to produce the pellets, 14 units of energy are gained, through burning. By comparison, a 2006 University of Minnesota study found that corn ethanol has a 1.25:1 energy balance.

There’s also reed canarygrass, a native Maine species known for its ability to grow high yields in cool seasons.

Studies in the north central United States and Europe have shown that reed canarygrass can yield 4 tons to 8 tons per acre, depending on fertilization regimes. If replicated in Maine, Plant says, commercial production cost estimates are $115 to $130 per ton of pellets — $5.50 to $6.25 per million BTU. Wood pellets average $9.50 per million BTU.

When home heating oil is $2.70 a gallon, Mainers pay $19.50 per million BTU.

Compared with other biofuel crops, perennial grasses conserve soil resources, sequester carbon and nitrogen in their root systems, and can serve as valuable wildlife habitat. The perennial grasses have moderate to high productivity, stand longevity, low nitrogen requirements, and resistance to pests and diseases. They also are well adapted to marginal farmland and can be successfully established in northern climes.

And unlike forage crops harvested a couple times a year, energy grasses are cut annually at the peak of maturity. Baled perennial grass has a moisture content of up to 15 percent, compared to upward of 50 percent moisture content of wood, which mandates extensive drying before pelletizing.

A large round bale of grass can produce up to 1,400 pounds of pellets, says Plant. It would take an average of 2 to 3 acres of grass to annually heat a typical northern home.

The grasses, like wood, contain natural lignins that act as gluing agents. For the additional binding needed to improve the energy density of grass pellets, UMaine researchers are exploring the use of patented technology that incorporates recycled, nonchlorinated plastics. Some of these plastics are even found on farms, including greenhouse film and hay bale wire.

The recovered plastics such as polyethylene and polypropylene certified by the U.S. Environmental Protection Agency to be used as fuel are highly refined hydrocarbons with low levels of inorganics and high BTU values. Recent work has shown that bioplastics, such as poly lactic acid or PLA, which are difficult to process in conventional recycling operations, can also be used in pellets.  Grass pellets may burn a bit faster than wood, Plant says, but with the plastics as binder are more energy-dense.

However, when burned, grass pellets tend to be higher in ash content than wood — up to 5 percent versus 1 percent. Grass also has a higher natural chlorine content, making the pellets more corrosive than those made of wood. In Europe and elsewhere, research is focusing on new technology for ash management in boilers and stoves, as well as higher-grade metals that better resist corrosion.

“This is not just about (alternative) pellets, but agriculture as a whole,” Plant says. “It’s about finding an alternative crop to improve the economic climate for farmers while developing a resource that can be used by the general population — economic development and an environmentally friendly, renewable resource.”