Dairy waste AD system kicks off biomass conference tour
Raising his voice over the loud noises of the anaerobic digestion (AD) system at Fairview Swiss Cheese in Fredonia, Pa., Rick Koller explained the ins and outs of the process to tour participants of the Northeast Biomass Conference & Trade Show held in Pittsburgh Oct. 11-13.
Koller, president of John Koller & Sons Inc., which operates Fairview Swiss Cheese, told the crowd that the combined-heat-and-power AD system runs on the organic portions of the whey byproduct from the cheese-making process. From the whey sugars, the digester produces enough biogas to generate 290 kilowatts of power, which is net metered through an agreement with First Energy, Koller explained over the glugging in the tanks and the whir of engines. The system will also soon provide 1.5 million Btu of process heat.
The $3.1 million facility, located a few hundred yards behind the cheese plant and housed partially inside its own warehouse, offers Fairview electric and oil savings, Koller said, but most important it provides waste stream disposal. Before operation of the AD system in 2009, Fairview would haul whey permeate to fields for distribution onto the land. “We’re not doing that anymore,” Koller said. The digester has reduced land-applied effluent by 90 percent.
But it’s not all glory, he cautioned, lamenting about costs of the system, no payback and nozzles frequently plugged with sand. “There’s always upsets,” he said, adding that he is just now learning about certain maintenance aspects of the system. Still, he said the process is certainly a benefit to the company. “Sometimes, what we’re doing right, we’re not sure, but it’s working.”
Koller also walked his audience down a small hill to the power generator, appropriately located closer to the cheese plant than the digester. Fairview takes in about 35,000 gallons of milk each day, but at full capacity can handle up to 50,000 gallons per day. The plant is the largest Swiss cheese producer in Pennsylvania, pumping out about 8 million pounds per year.
One of issues Koller has faced operating his first anaerobic digester has to do with the fact that the original system design incorporated two concrete digester tanks. Fairview, however, chose to save money and just erect one, right outside the system’s designated warehouse. Anaerobic digesters vary in design, Koller said, and many won’t have the same problems he has encountered.
Although occasionally frustrated with the learning curve of operating the anaerobic digester at Fairview, Koller still emphasized its enormous environmental benefit, as well as the advantages of in-house waste disposal.
“Will this [AD process] ever pay for itself? Barely,” he said. “But I’m treating my waste on-site.”