Perdue composting venture full speed ahead
BLADES, Del. (Nov. 7, 2017) — The idea is the same — recycling poultry litter for alternative uses — but the process used at Perdue AgriRecycle south of Seaford, Del., has changed dramatically in the last year.
Perdue AgriBusiness has made a $12 million investment in a composting facility, AgriSoil, situated on an adjacent 26-acre field.
The new facility opened in January and is now up to full speed.
After 16 years of processing poultry manure by screening, drying, heating and pelletizing the material for use in by farmers, gardeners, landscapers, and turf managers, Perdue AgriRecycle has changed its production model and its end product.
Joe Forsthoffer, director of corporate communications for Perdue Farms, explained that Perdue AgriBusiness has switched to composting, which has a much smaller environmental footprint and increases nutrient recycling capabilities.
“Of course, our commitment to accept litter from farmers who don’t want their litter remains,” Forsthoffer said.
“Sixteen years ago [pelletizing] was state-of-the-art technology. We take a continuous look at technologies. There are any number of technologies for alternate uses of poultry litter. We’re looking for commercially viable technologies with which we don’t end up with an additional by-product,” he continued.
Composting uses minimal energy and allows use of everything that comes out of the process.
Composting has the advantage of reducing the energy required to convert the raw poultry litter to a marketable product, and uses a biological process rather than mechanical.
Composting also expands the capability to handle other poultry byproducts — not only litter, but hatchery waste and the fat and blood nutrients from processing plant waste water which used to be land applied.
“It’s all recycled. We divert more nutrients from ground applied to processed,” Forsthoffer said.
AgriSoil is expected to nearly double the amount of litter and byproducts that are recycled and relocated to as much as 80,000 tons per year.
One ton of raw material yields about 1,100 pounds of compost, a highly organic material that has several alternative uses.
With the pelletizing process, the volume remained about the same.
Scott Raubenstine, vice president of ag services at Perdue AgriBusiness, said the weight of poultry litter when removed from a chicken house is about 35 percent moisture.
It took a lot of energy to reduce that moisture to 12 percent at AgriRecycle.
The pelletizing process was not only energy intensive, Raubenstine said, but very hard on equipment.
“There’s a lot of sand, which causes erosion of equipment,” he said.
The biological process uses heat, moisture, carbon-to-nitrogen ratio and naturally occurring microbes to reduce the mass of the material nearly in half.
“Happy bugs (microbes) are our goal,” he quipped.
“This is a very stable product,” Raubenstine continued. “There are 12 specs we must hit before we sell it. We feel it is the best in the country, and this is the cleanest facility in the country.”
Raubenstine described the composting process.
Poultry manure and other byproducts are mixed with wood chips and put into a long vessel, called a bunker.
“We count the buckets of wood in proportion to other materials and blend it to our specifications,” he said.
The bunker is covered with a specially woven tarp which keeps additional water out and keeps odor in. Air is blown in through the bottom of the bunker.
The temperature under the tarp is monitored constantly to assure that it reaches 160 degrees, which kills pathogens.
The process meets a classification called PFRP: Process to Further Reduce Pathogens.
“We hit PFRP in the bunker within the first few days, and then we hit it again,” Raubenstine said. The compost is kept at a temperature above 130 degrees for at least 15 days.
The entire process takes 60-70 days.
Each bunker is “turned,” or mechanically mixed, five times by a Komptech row turner before the compost leaves the area.
The row turner pulls a reel of hose and can add more water if needed while turning the compost.
“We verify there is no contaminant from anything else,” Raubenstine added. The process is a closed loop system, producing a consistent stock.
The material still registers 130 degrees when moved to the “South Pod” where it is screened to remove remaining wood chips.
The wood chips are re-used in another compost pile.
The resulting “fines” are analyzed per specifications of the Department of Natural Resources and Environmental Control.
Once the compost has passed analytical criteria, the pile is labeled “Can Be Sold.”
Raubenstine said the finished product contains about 6-percent calcium because of egg shells from the hatcheries.
The end result, called BetR Compost, is described as a “soil conditioner composed of composted, recycled poultry nutrients, processed green forestry materials and poultry manure.”
High in organic matter, it is sent to local distributors to be blended, bagged, shipped out of the area and sold.
Recently 25 truckloads were sent to New York to blend in soil there for lettuce and spinach production.
Some local farmers are trying the product, both for dry land production and fields under irrigation.
Local landscapers and nurseries have also been using the compost, and AgriSoil is working with turf farms on a 10-acre trial plot.
Employees are trained specifically for this process, Raubenstine said. AgriSoil is part of the U.S. Compost Council, which provides training at conferences.
He added that the old AgriRecycle building is still being used as Perdue continues to be part of the solution for poultry growers with excess litter. It may someday be used as a bagging facility.
A separate organic compost product is also being produced in addition to the conventional compost.
Raubenstine said the organic product is only produced at a specified time so that all of the equipment can be cleaned out before composting starts.
The organic compost is made of litter and wood chips only.
The “all natural” compost also uses poultry by-products.