By Stephanie Schupska
University of
Georgia
That’s good news in Georgia, where chickens, specifically broilers, rank No. 1 in the state’s agriculture, with a leaving-the-farm value of almost $4 billion. Poultry litter is mostly manure mixed with a bedding material such as wood shavings.
Two and a half pounds of litter per broiler is 2.5 pounds of by-product waiting to be converted into something usable, said Jimmy Palmer of the U.S. Environmental Protection Agency. With funding from an EPA grant, UGA researchers are searching for ways to add value to poultry waste.
“This will help us collectively deal with environmental issues of growing agriculture,” said Palmer, an EPA regional administrator.
“A waste is a terrible thing to mind,” he said, twisting a common phrase. “We’re looking for better ways to deal with waste.”
Through a process called fractionation, the UGA researchers plan to produce two types of materials from the poultry litter, separating the fine and coarse parts, said Mark Risse, a UGA Cooperative Extension engineer and member of the research team.
The scientists form the fine, nutrient-rich material into pellets for fertilizer. Because the processed fertilizer pellets would allow a slower release of nutrients into the soil, pollution from pathogens and nutrients in the poultry litter would be reduced.
“Most poultry litter is currently being directly land-applied as fertilizer,” said K.C. Das, coordinator of the UGA Biorefinery. “It makes sense to a point. But in north Georgia, there’s not enough land to spread the litter. Through this process, we’re producing a better energy product as well as a better fertilizer.”
The research team puts the coarse, energy-rich poultry litter material through an intense heating process called pyrolysis to create char and bio-oil. The char can be used anywhere charcoal is used. Bio-oil can be refined further and used as diesel-like fuel.
UGA engineers say developing a cheap source of energy from poultry litter would provide a cleaner source of energy, helping the state grow in an economically and environmentally sustainable way. They estimate that in the United States, using poultry litter as fuel could save 283 million gallons of fossil fuel.
“Two or three companies are looking at Georgia right now,” Risse said. “They’re looking at pelleting litter for fertilizer. There’s a very real opportunity for research that can be used not 10 years from now, but now.”
“A lot more is said than usually done, and we’re about to do it,” Palmer said of the project.
Besides Risse and Das, the UGA research team includes Cooperative Extension engineer John Worley, professor Sid Thompson and graduate student Kaushlendra Singh.
The project builds on work Thompson did 15 years ago and had to shelve due to a lack of application at the time. Now, with the demand for alternative fuels increasing, his halted research can continue.
The project team is in the process of showing they can break up poultry litter into two parts and use both. The researchers will also have to determine whether the processes should be done at centralized locations across the state or at individual farms.
“Poultry litter represents two times the energy consumption on a farm,” Das said. “You have everything you need to produce energy on the farm already.”
