New Process Converts Poultry Litter into Bio-oil
BLACKSBURG, Virginia, August 29, 2007 (ENS) - Each year in the United States the poultry industry produces more than 5.6 million tons of litter - a mixture of bedding, manure, feathers, and spilled feed.
Now, a team of researchers in the College of Agriculture and Life Sciences at Virginia Tech is developing transportable pyrolysis units that will convert poultry litter into bio-oil that can be burned as fuel right at the poultry farm, providing an economical disposal system while reducing environmental effects and biosecurity issues.
Team leader Foster Agblevor, an associate professor of biological systems engineering, says current disposal methods such as land application and feeding to cattle are under pressure because of pollution of water resources due to leaching and runoff and concern about mad cow disease contamination in the food chain.
There are also concerns that poultry litter can harbor diseases such as avian influenza. While bird flu virus can be spread on people's shoes, vehicles, and through movement of litter.
"The self-contained transportable pyrolysis unit will allow poultry producers to process the litter on site rather than having to haul the litter to a separate location," Agblevor said. "In addition, the thermochemical process destroys the microorganisms reducing the likelihood of the transmission of disease to other locations."
Agblevor is working with poultry growers to test technology that would convert poultry litter to three products - bio-oil, producer gas, and fertilizer.
The pyrolysis unit heats the litter until it vaporizes. The vapor is then condensed to produce the bio-oil, and a slow release fertilizer is recovered from the reactor. The gas can then be used to operate the pyrolysis unit, making it a self-sufficient system.
"The type of poultry litter used will affect the amount and quality of the bio-oil produced and ultimately will impact the producer's profitability," Agblevor said. "Finding the right set of conditions for the poultry litter is key to the adaptation of this technology."
This research is part of an effort by Virginia Tech researchers, Virginia Cooperative Extension specialists and agents, conservation organizations, state agencies, and private industry to determine the most effective means to support the agricultural community and manage the excess nutrients in the Shenandoah Valley.
The research is being funded by a $1 million grant from the National Fish and Wildlife Foundation's Chesapeake Bay Targeted Watershed Program.
Copyright Environment News Service (ENS) 2007. All rights reserved.