Maine Technology Institute funds fuel pellet projects

By Ryan C. Christiansen
Web exclusive posted Feb. 6, 2009, at 9:57 a.m. CST

The Maine Technology Institute, a private, non-profit organization created and funded by the state of Maine, has awarded $20,750 in grants for fuel pellet-related projects.

X Caf� LLC, a Princeton, Mass., coffee extract production company with a roasting and extraction facility in Portland, Maine, has been awarded $12,000 to produce fuel pellets from waste coffee grinds. According to Paul Kalenian, president of X Caf�, the company imports green coffee beans from around the world. The roasting and extracting facility then roasts the beans, grinds them, and extracts the flavor and fragrance out of them. The process produces a lot of leftover biomass.

"It turns out that a roasted coffee bean is 80 percent or more wood fiber and 20 percent or less extractable flavors and fragrance," Kalenian said. "For every 40,000-pound (shipping) container of green coffee that comes in, we have about 30,000 pounds of coffee grind waste going out the door and so we end up with between 200,000 to 400,000 pounds of spent coffee grinds per week."

For the past nine years, X Caf� has been trucking the spent grinds to a power plant in Greenville, Maine, where they are co-fired with woody biomass to generate steam to produce electricity. "We have never, ever sent any coffee grind waste to a landfill," Kalenian said. "We have 100 percent recycled our coffee grounds from day one." The main drawback is that Greenville is a seven-hour roundtrip journey from Portland. At 100,000 pounds per load, X Caf� sends two to four truckloads to Greenville each week-and business is growing. X Caf�'s primary product is liquid coffee that is 30 times stronger than a cup of coffee, Kalenian said, and it's the flavoring that goes into many of the new popular energy drinks. "Our extraction business is growing remarkably," he said, "and may double in the next 12 to 14 months."

Kalenian said the company has consulted with California Pellet Mill for pelletizing the coffee grinds. "Essentially it's going to involve an industrial silo so that the waste coffee will go directly into that silo," Kalenian said, "and from the silo into a rotary drum dryer-probably fired by gas-and from there into the pellet mill." He said the pellets will include approximately five percent paraffin as a binder. "And then we're going to repackage the pellets directly back into the same burlap bags that the coffee came in originally." X Caf� expects to be pelletizing up to 120 tons of java pellets per week in the near-term, Kalenian said, and more as the coffee extraction business continues to grow.

Kalenian said X Caf�'s java pellets will be sold through a chain of hardware stores in the Northeast that also sells pellet stoves. "The beauty of coffee grind waste is that it has much higher oil content than wood," he said. "It has a higher British thermal unit value, [approximately] 10,000 Btu per dry pound versus 8,200 to 8,400 (for wood)."

When Kalenian mentions X Caf� will be pelletizing coffee grinds for use as a fuel in pellet stoves, "the comment I get back," he said, "is �Well, won't that smell nice?' Well, not if we can help it. Because if there is fragrance remaining to the coffee grinds, then we haven't done our job on extraction."

Another Maine company has received an award for a fuel pellet-related project. Thermal Closure LLC, a joint venture between Joseph Seale, a consulting engineer in Gorham, Maine, and Corinth Wood Pellets LLC in Corinth, Maine, has been awarded $8,750 to develop a new technique for drying feedstock for the production of wood pellets.

"We are very interested in trying to improve the efficiency [of drying] wet sawdust," Seale said. "Right now, [Corinth Wood Pellets] is drying sawdust using hot air from a furnace. We are interested in trying to close that drying cycle and to dry the sawdust in superheated steam."

Water for the steam system would be replenished using evaporated moisture from the drying process, Seale said. "The basic principle is to recycle the heat of vaporization of all of that water that is coming out of the sawdust," he said, "and to squeeze that steam, turn it back into liquid, and get the heat back out that went in on evaporation, and then reuse that heat."

Seale said 70 percent of the energy used for making wood pellets goes into drying the feedstock. "We would be looking to try to save half or more of that 70 percent," he said.

The short-term goal is to find out whether the superheated steam-drying process is physically and economically feasible. "If the answer is yes, we are going to be looking at a bigger investment in a pilot project," Seale said. He has filed two provisional patent applications for the technology and plans to file a utility patent in April.