Manure Manager

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Poultry manure gasifier to reduce nutrients flowing into Chesapeake Bay


The plan by a company called EnergyWorks to build a $30 million thermal gasification plant near Gettysburg, Penn., to process manure generated by the state’s largest egg producer is one of those ideas that seems to have “can’t miss” written all over it.

The plan by a company called EnergyWorks to build a $30 million thermal gasification plant near Gettysburg, Penn., to process manure generated by the state’s largest egg producer is one of those ideas that seems to have “can’t miss” written all over it.

The EnergyWorks plant is being built on a site adjacent to four Hillandale Farms egg-laying facilities located within the Susquehanna River basin, which is part of the Chesapeake Bay watershed. It will produce syngas that will be used as a fuel source to generate steam to drive a turbine to produce just over three megawatts of electric power. The gasification process will also produce between 13,000 and 16,000 tons of ash byproduct annually that will be marketed as an animal feed supplement because of its beneficial mineral content. All told, the process will dispose of about 240 tons of poultry manure per day.

“We felt that manure land application was not the best avenue for a long-term use of manure,” says Ron Ballew, Hillandale Farms environmental manager. “Hillandale, being a progressive company, we were interested in looking at the green way of processing our manure. EnergyWorks seemed to have a plausible alternative to land application with long-term environmental benefits.”

In addition to generating marketable products and providing a long-term manure management solution for Hillandale Farms, it will also eliminate the potential nutrient runoff into the nearby Chesapeake Bay if it had been land applied as has been the conventional practice to this point.

“The water quality environmental benefits from this project are really extraordinary and I think it will demonstrate that, through technology, you can really transform animal agriculture and come up with a much more sustainable approach,” says Patrick Thompson, EnergyWorks CEO. Land-applied manure generated from the area’s agricultural operations is one of the causes of algae growth in the Chesapeake Bay, depleting oxygen in the water and creating marine “dead zones.” Since agriculture is the largest sector of Pennsylvania’s economy, the state is very interested in doing its part to improve water quality in the Chesapeake Bay.

However, the benefits of this manure gasifier project extend far beyond renewable energy and water quality. The project will also eliminate an attractive living environment for rodents and insects in manure storage sheds, resulting in greater food safety. The project will reduce farm ammonia emissions by 50 percent, eliminate over 34,000 tons of carbon dioxide-equivalent greenhouse gases annually, reduce manure storage inventories by 97 percent, eliminate manure application on 23,000 acres of land, and achieve 3.5 to 4.4 percent of Pennsylvania’s 2025 goals of reducing nitrogen and phosphorus loading to Chesapeake Bay.

As yet another example of how advanced manure management technology delivers not only an environmental dividend but also a financial dividend to the farm, the gasifier simplifies farm operations. The poultry manure processing plant has been designed to process the entire amount of manure generated by the Hillandale egg-laying operation of five-million birds. The plant will provide a complete manure management solution to Hillandale Farms. About half of the power generated by the plant will be supplied to Hillandale Farms. EnergyWorks will sell the surplus power to the public power grid through an electric distribution utility.

EnergyWorks plans to complete construction of the plant and begin operating by October 2012. The company is finalizing its financing for the project, which includes an investment by EnergyWorks, a federal American Recovery and Reinvestment Act (ARRA) grant, and repayable loans from the State of Pennsylvania.

In addition to marketing electricity and animal feed supplements, EnergyWorks is also actively marketing Nutrient Trading Credits that will be generated once the facility is operational. The Pennsylvania Department of Environmental Protection has certified the facility as a nutrient credit generator with a projected annual capacity of one million nitrogen credits and 53,000 phosphorus credits, making it Pennsylvania’s largest certified credit generator.

“We are in discussions with several buyers now and there is a lot of interest in purchasing credits from a source like this because the credits that we are producing can be quantified and verified in real time,” says Thompson. “They are derived by measured amounts of nutrients that are kept out of the environment and that is very different from some of the other ways that people generate credits.”

Manure will be trucked on a just-in-time basis from storage facilities at each of Hillandale’s four egg-laying sites to the EnergyWorks plant. The live bottom trucks enter a building where they are scaled and the manure is dropped into a receiving bin below the floor.

“The manure is contained throughout the rest of the process in a closed system, generally at negative pressure to prevent any release of odors or dust to the environment,” says Thompson.

The waste material is just poultry manure, and does not include any other material used for bedding, such as wood chips or peanut husks. Other factors that work in EnergyWorks’ favor are the consistent feed regimen given to the birds by Hillandale Farms and the continuous manure collection system that allows EnergyWorks to retrieve the manure on a just-in-time basis. All these factors are important for the company to operate its gasifier as efficiently as possible and to maintain high and consistent quality in its animal feed supplement product.

From storage, the manure is conveyed into a drying system that aims for about 20 percent moisture content.
“We try to maintain a very consistent moisture level going into the gasification process,” says Thompson. “The more consistent the feedstock going into gasification, the more feasible it is to have a highly controlled gasification process.”

Once dried, the manure is fed into the thermal gasifier. Essentially what happens in the gasifier is that the remaining moisture is evaporated, the organic solids are converted into syngas, and ash containing the minerals is continuously conveyed to storage silos for regular shipments to buyers. The main physical difference with this gasifier compared to other staged combustion systems is that rather than stacking the components vertically as in a single box, the pieces are strung together horizontally to give EnergyWorks better process control.

“We have broken the process into multiple steps and in that way, we are able to use the equipment for each step of the process that is optimized for its function,” says Thompson. “We realized how important it was to control the process in order to control our mineral byproduct.”

The syngas produced by the gasifier is ducted to a thermal oxidizer, where it is ignited and burned. The heat generated from the combustion of the syngas heats water within a heat recovery boiler, providing superheated steam. It drives the power turbine. Some of the steam is also used in the drying system.

The ash is removed continually from the gasifier and placed in storage silos. Combustion gases produced by the process pass through a bag filtration system before being released into the atmosphere.

“We have an air quality permit and we expect this to be a very clean technology,” says Thompson. “The two main culprits of water pollution are nitrogen and phosphorus, and these thermal processes break down the polluting nitrogen compounds in the manure so that you are left with non-polluting nitrogen gas as the main constituent going out the stack. The phosphorus is almost entirely captured in the mineral product.”

He described the facility as more of a biorefinery than simply a renewable energy project because the most valuable commodity produced is not power but the mineral supplement. The world demand for phosphorus and potassium is increasing as the population increases and the demand for animal protein increases, which could lead to scarcity of these minerals.

Through its gasification process, EnergyWorks is recovering and recycling these valuable nutrients.

EnergyWorks has more than 15 years’ experience in energy and infrastructure management, having owned and operated numerous energy facilities.

“We have worked extensively with industrial and commercial customers building, owning and operating energy infrastructure,” says Thompson. “In 2006, we began to look at taking this business model to the agricultural sector and building, owning and operating facilities using agricultural biomass as feedstock.” The pollutants are kept out of the environment, which, he adds, is a completely different approach than most manure management systems have taken in the past.

The company began in 1995 as a partnership between San Francisco-based Bechtel Corporation and a U.S. utility based in Portland, Ore., called Pacific Corporation. EnergyWorks began with the mission to build, own and operate facilities to distribute energy, working mainly in the international market. Its first project developments took place in Latin America, Brazil and Venezuela. The partnership was later involved in developments in Spain. It was purchased by a Spanish utility in 1999. What followed was considerable growth for the next two years with construction and operation of energy projects in Brazil, Argentina, Venezuela, Mexico and Spain. A reorganization of the company created an opportunity for a management buyout and it has been operating as a management-owned company since 2001. In 2003, EnergyWorks acquired the energy infrastructure for a large shopping complex in Pennsylvania and currently owns and operates the infrastructure to supply the energy needs of the complex. Since 2006, it has been investigating agricultural biomass and taking its energy business model to the agricultural sector in Pennsylvania.

The Hillandale project represents a template that EnergyWorks believes it can market with other major egg-laying operations.
“We are in discussions with others about similar projects, and we would like to build more of these,” says Thompson. “The market is huge. The egg-producing region mainly follows the grain belt in the United States from Iowa to Pennsylvania.”