it is reabsorbed when the next crop grows making it carbon neutral. Giant King Grass can be burned either directly or in pellet form as a replacement for coal or oil in power plants or used to produce biomethane in anaerobic digesters. Giant King Grass is a nonfood crop and can be grown on marginal lands not suitable for growing food crops. Viaspace says the grass is low cost because it yields more than 44 dry tons per acre annually. Combusting grass results in one-fourth the cost of solar or wind energy. Ag-to-energy is predictable and constant, as agricultural biomass can power a plant 24/7. “As pellet demand increases, agricultural pellets, especially pellets from dedicated sustainably grown energy crops will be in great demand,” Kukkonen says.
Combustion Technologies In addition to an existing supply chain, it is necessary to have the energy generation technologies to capitalize on biomass benefits. Various companies are actively developing boilers and furnaces compatible with agricultural feedstocks that minimize the challenges of slagging or clinkering. Skanden Energy is a start-up company, based in the Northeast U.S., which markets commercial- and residential-scale multifueled biomass boilers using gasification to process feedstocks such as agricultural bio-
mass in in loose, chip, pellet, briquette or bale form. In addition to the multifueled boiler systems that can process biomass with up to 50 percent moisture, the company markets residential pellet boilers. The boilers range from 30,000 to 10 million Btus. To ensure the feedstock gets to the boiler efficiently, Skanden also provides storage and fuel feeding equipment, including silos, bins, moving wedge floors, bale cutters, conveyors and automatic bale feeders. “We take automation to a new level,” according to Skanden. “We offer multiple cleaning devices that remove ash automatically from the combustion chamber, boiler tubes and exhaust gases.” The company provides control panels that can be connected to the BIOMASS BOILER: In 2010, Skanden installed a boiler at the Kingfield Elementary and Middle School in Maine, in Internet to notify the consumer 2010, that will save the school $34,000 annually in fuel costs. and the fuel supplier about fuel and maintenance issues. Skanden’s multifueled boilers are manufactured with stainless metals shown the boilers are more than 90 percent that eliminate corrosive tendencies and en- efficient. courage multifuel use. Laura Colban, SkanColban adds that although the interden’s CEO, says independent tests have est in agricultural fuels is increasing, some
42 BIOMASS POWER & THERMAL | NOVEMBER 2011
PHOTO: SKANDEN ENERGY
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