Turning chicken waste into energy is not easy. It requires expensive systems, a high degree of mechanization, and an astute business sense to use every part of the manure. And it probably won’t pay for itself, at least not in the near future.
Patrick Thompson is doing it anyway.
His company, Energy Works, is turning the manure from 5 million egg-laying hens into power. That energy not only runs the nutrient recovery plant and makes it self-powering; it also lets him pay the bills by selling electricity back to the grid and to the egg farm to run its operations. More importantly for the Chesapeake Bay, it converts 240 tons of manure a day into a useful product. Were it not for Energy Works, Thompson said, haulers would take much of the manure to Maryland, where it would be applied on lands closer to the Chesapeake.
“This is a full-scale commercial plant now,” Thompson said as he gave yet another tour of his southern Pennsylvania facility. Recent visitors have included Chesapeake Bay Commission members, Bay Program officials, Maryland Secretary of Agriculture Joseph Bartenfelder and various legislators. “We are able to show what it is we are keeping out of the environment, how many pounds of nitrogen and phosphorus.”
Other places in the country are reducing their phosphorus loads by trucking the manure farther from watersheds that have too much of it. Thompson is reducing the load by turning the manure into something else — energy to heat the manure-to-energy plant, and an ash rich in calcium and potassium that can be precision-applied to fields. This transformation, Thompson and others argue, is the only solution for the Chesapeake Bay’s poultry manure problem. And the sooner the politicians and scientists acknowledge it, the sooner they will see the results in water-quality monitoring.
“My argument is, over the past several decades, the food animal agriculture industry has evolved dramatically, and the majority of food is produced on CAFOS (concentrated animal feeding operations). And in the case of poultry, it’s a very high percentage. If you can manage the CAFOs, you go a long way toward managing the overall problem,” Thompson said. “Our goal is to create zero-waste solutions for CAFOs. If we can manage the waste from CAFOs, smaller agricultural operations can rely on traditional management methods.”
Thompson’s solution comes on the heels of Maryland’s attempts to open a manure-to-energy plant on Maryland’s Eastern Shore that would have been able to handle much of the 228,000 tons of excess manure that the state’s many poultry producers now sell to fellow farmers. Many of those farmers apply it to fields that are already saturated with phosphorus. This ultimately leads to much of the excess phosphorus entering streams, rivers and the Bay
The administration of former Maryland Gov. Martin O’Malley developed a proposal to build a manure-to-energy plant and awarded the project to the lowest bidder in 2013, Green Planet Power Solutions. That company has yet to secure a site or a permit to operate.
An Irish company, BHSL, is piloting a Maryland program for an on-farm energy plant for chicken manure. And several dairy farms in Pennsylvania have installed methane digesters at great expense to turn dairy manure into heat for their farms as well as useful products, like bedding for the cows. But in these operations, the farmers have to be active participants in the management. In an operation like Thompson’s, all farmers would have to do is allow someone to take their manure away to turn it into a useful product.
Ann P. Swanson, executive director of the Chesapeake Bay Commission, brought the commission’s membership of legislators and policy-makers to tour the plant a couple of years ago. She said she remains convinced Thompson has not only a viable solution to a persistent problem, but also one that provides a benefit.
“They’re not just making energy. They are reducing pollution while they’re doing it,” she said. “No other renewable energy does that.”
Energy Works’ Gettysburg plant is a partnership with Hillandale Farms, whose hens supply the manure. But Thompson considers the operation a public-private partnership with the state of Pennsylvania, which has started a nutrient credit-trading market that he hopes will eventually benefit Energy Works. The state has worked with the company on monitoring emissions and structuring an operating permit. The state also helped finance the $40 million plant through long-term, low-interest loans.
Dairy manure works well in digesters because of its high moisture content. Chicken manure tends to be dry. But Energy Works has the worst of both worlds: egg-layer manure is not moist enough for anaerobic digestion, but too moist for direct thermal conversion.
So, Thompson’s team sends the egg-layer manure through a pre-conditioning process to dry it out and take the levels of moisture down from 60 percent to 20–30 percent. The manure is dried and stored in a silo. Later, it goes into the gasifier, where the organic solids became a gaseous fuel known as synthesis gas. It then enters an oxidizer, where it’s combusted to produce heat. Heat produces steam, and steam provides thermal energy for the manure-to-energy process and drives a steam turbine to generate electricity.
The steam exhausts into an air-cooled condenser; the condensate is collected in a tank and circulated to the boiler to make more steam. Fans draw the flue gas from the burning manure through the bag house, a large filter system that traps particulates to clean the flue gas.
In the end, there are three products: 3 megawatts of electricity, white bags full of 1,500 pounds of ash apiece and nutrient trading credits.
Nutrient credits can be a revenue source. Under a nutrient credit plan, wastewater treatment plants, power plants and other polluters who cannot meet the terms of their permits would be allowed to buy credits from Energy Works to make up for whatever pollutants they could not reduce.
Energy Works had counted on getting a crack at those credits, but the market has not emerged the way Thompson had hoped.
First, the state allowed wastewater treatment plants with extra capacity to sell that capacity for credits, simply because they were not yet using it. Those inexpensive credits flooded the market, which meant Energy Works couldn’t make any money selling its own credits.
Second, the state allowed nutrient credits for manure hauling. Though the poultry companies own the flock, farmers are left with the manure at the end of a growth cycle. Haulers trucked the manure to Western Pennsylvania, where watersheds are also saturated with phosphorus, but where the rivers ultimately flow into the Mississippi River, thus avoiding Chesapeake Bay watershed restrictions.
Thompson is hoping new legislation in Pennsylvania will close some of those loopholes and save nutrient credits for companies that actually reduce the nutrients in the system.
Another problem is the regulation of the manure. Much of the manure comes from CAFOs. But CAFOs often don’t have much land for crops, and haulers take the manure to grain and soybean farms, which are not regulated under those same laws. Essentially, the source of pollution travels from a point source to a nonpoint source
A nuclear engineer who spent much of his career at Bechtel Corp., Thompson said he has always considered himself an environmentalist. Manure to energy is the latest iteration of that philosophy. It is, he said, the right thing to do.
The challenge, he said, “is not a matter of technology. It’s a matter of policy,” adding, “you certainly don’t do it because it’s a great fuel. You do it for environmental reasons.”