Researchers from North Carolina State University and West Virginia University have developed a new technology that can reduce air pollutant emissions from some chicken and swine barns, and also reduce their energy use by recovering and possibly generating heat.
Specifically, the research team designed, built, and evaluated a proof-of-concept unit that incorporates a biofilter and a heat exchanger to reduce ammonia emissions from livestock barns, while also tempering or heating up the fresh air that is pumped into the barns.
The pollution removal component utilizes a biofiltration mechanism, in which polluted air is passed through an organic medium, such as compost or wood chips, that contains bacteria. Those bacteria interact with the pollutants and break them down into harmless or less harmful constituents. Biofiltration also allows recycling of nitrogen because when the "spent" medium is applied on cropland, the nitrogen becomes available to the crops. However, biofiltration also introduces additional costs for animal agriculture operations. The researchers hope to defray those costs by reducing an operation's energy consumption.
Here's how their prototype works: warm, polluted air from the livestock facility enters the biofilter, and some of the heat is transferred to the heat exchanger. When fresh air from outside is pumped into the building, it passes over the heat exchanger, warming it up.
The prototype not only helps recover heat from the facility, it also produces its own heat. This heat is generated within the biofilter when heat-producing biochemical reactions occur for example, when the ammonia is converted into nitrate by bacteria. The heat from the biofilter is also routed to the heat exchanger.
Maintaining the appropriately high temperature is important for chicken and swine operations, because it is essential for rearing chicks and piglets to maturity.
"The technology is best suited for use
|Contact: Matt Shipman|
North Carolina State University