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Systems for Controlling Air Pollutant Emissions and Indoor Environments of Poultry, Swine and Dairy Facilities

D.G. Overhults, A.J. Pescatore, R.E. Fehr
Department of Biosystems and Agricultural Engineering

Non-Technical Summary

In general, air quality and emission control technologies used for industrial sources appear to be uneconomical, and often impractical, for agricultural animal production. The purpose of this study is to improve understanding of animal interactions with the built environment, and to improve control of emissions from animal facilities.

2010 Project Description

Objective 1 - Reducing air pollution emissions - Experiments were conducted using small, laboratory scale, tubular reactors to determine the effects of moisture content on ammonia (NH3) removal capacity and nitrous oxide (N2O) production in compost biofilter material. Separate moisture loss experiments were performed in addition to the gas monitoring work as a means of minimizing the impact of moisture measurement on gas activity.

The degradation of NH3 and the production of N2O were investigated for constant air flow rate and relative humidity, particle size, and initial gas concentration. A Drying Characteristic Curve was developed to describe relative moisture condition of the material in terms of drying rate as a function of time. The data suggests that there is a (material specific) critical moisture content zone prior to transition from the constant rate to the first falling rate drying phase (35 to 45% w.b.) which both minimizes N2O production and maintains NH3 nitrification with an acceptable biofilter efficiency.

Results also underscored the need for reliable moisture control. To this end, the University of Kentucky BAE Dept. and the University of Illinois, ABE Dept. established a joint collaboration to develop and test a capacitance-based moisture sensor. A current version of the new sensor is now being used in conjunction with a soaker hose water delivery system to determine the effect of controlled moisture application on the degradation of NH3 and the production of N2O in quarter-scale biofilters. The Volumetric Production Instrument was also replicated to form six chambers for analyzing gas production rates from temperature controlled bioreactors.

Objective 3 - Energy efficiency - The Kentucky Poultry Energy Efficiency Project was concluded with 42 growers having received on-farm energy assessments that provided baseline energy use and recommendations for potential energy efficiency improvements to their facilities.

Two statewide grower education conferences were conducted at five different locations with 275 growers and industry advisory personnel attending. An additional workshop was provided for growers in one production complex to present on-farm assessment data from that specific complex. A quarterly newsletter was produced and distributed to all growers (approx. 800) and a website (http://www.poultryenergy.com) was continually updated with new materials. A 2-day online webinar (Cold Weather Ventilation), produced by the University of Georgia, was made available to KY poultry growers at 7 locations.

Energy audits and accompanying technical reports were provided for poultry and dairy growers who applied for energy efficiency cost-share funds from both the USDA Rural Energy for America Program and the Kentucky Governor's Office of Agricultural Policy.

One grant proposal was submitted and funded to expand energy auditing capability in support of USDA and other energy efficiency programs. Kentucky, Illinois, and Minnesota also jointly prepared and submitted a research proposal to USDA for a 5-year project to mitigate the impact of climate change by improving energy efficiency in swine production.

2010 Impact

Objective 1 - Reducing air pollution emissions - Combined results from several studies have led to the definition of a critical moisture content where N2O production is minimized while maintaining suitably high conversion rates for NH3. Establishing a critical moisture condition (for the "wood chip" based compost) set constraints for refining the capacitive sensor which now utilizes insulated, small form-factor plates for moisture sensing. The development of the VPI chambers allowed for longer term data collection of biogas collected directly from liquid swine manure.

The laboratory apparatus developed for this area of the research represents a significant opportunity to quantify other inputs to the system, i.e., temperature, changes in diet, effect of stirring, effect of aeration, dilution, solids concentration, etc., which may offer additional benefits in controlling GHG emissions. Much of the scientific method has resulted in the establishment of standards which will be used to determine the viability of alternate materials for use in compost based biofilters and installations.

It is now believed that individual, customized biofilter cells may be developed to address specific contaminants within an airstream, and that those cells may be used in series to achieve the desired air quality standards for animal housing emissions. Work in this project contributed to two M.S. degrees (Sales, 2008 and Dutra de Melo, 2011 - anticipated), one Ph.D. degree (Maia, 2010), one Post Doctoral Study (Souza, 2010), and one undergraduate research project, (Rodrigues, 2011).

Objective 3 - Energy efficiency - Baseline data from on-farm energy assessments showed that KY broiler growers use 4 to 9 gallons of LP gas (or fuel equiv.) and 25 to 55 KWh of electricity for each 1000 pounds of birds produced. Nearly all farms had at least one potential energy efficiency improvement. Adding ceiling insulation, changing from incandescent to fluorescent lighting, and installing attic air inlets were potential improvements that were frequently identified, often with simple payback periods less than 5 years.

Many growers could likely reduce energy use below 5.5 gallons of LP gas and 35 kWh of electricity per 1000 pounds of birds produced by implementing identified energy efficiency improvements. Energy audits and technical reports were provided for 12 USDA/REAP projects (broiler & dairy farms) which had a total project cost of $724,633. Total requested cost-share (25%) was $181,159. Funding for all projects was either approved or is currently pending. Assessments were also provided for 11 cost share (25%) applications to the Kentucky Governor's Office of Agricultural Policy with total project costs of $442,453 and grant requests of $93,056. All projects were approved for funding. The estimated annual value of energy savings from all USDA/REAP and KY GOAP projects is $370,000 per year.

2010 Publications

Maia, Guillherme del Neroa. 2010. Ammonia Biofiltration and Nitrous Oxide Generation as Affected by Media Moisture Content. Ph.D. Dissertation, University of Kentucky Graduate School.

Dutra de Melo, L., G.B. Day V, J.L. Taraba, and Guilherme Del Nero Maia. 2010. Assessment of a Moisture Application System for Compost Biofilters. Paper No. 1009176. ASABE Intl Mtg. June 20 - 23. Pittsburgh, PA. St. Joseph MI. ASABE.

Souza, C.F., G.B. Day V, J.L. Taraba, R.S. Gates, and W.P.M Ferreira. 2010. BIOG-C: Modeling the Volumetric Methane Production in the Anaerobic Digestion Process Applied to Swine Wastes. Paper No.1009181. ASABE Intl Mtg. June 20 - 23. Pittsburgh, PA. St. Joseph MI. ASABE.

Morello,G.M., D.G. Overhults, I.M. Lopes, J. Earnest, R.S. Gates, A. Pescatore, J. Jacob and M. Miller. 2010. Influence of Fan Operations on FANS (Fan Assessment Numeration System) Test Results. Presented at the ASABE Annual International Meeting, Paper No. 1009235, Pittsburgh, PA, June 20-23.

Lopes, I.M., D.G. Overhults, G.M. Morello, J. Earnest, R.S. Gates, A. Pescatore, J. Jacob and M. Miller. 2010. Assessing Air Leakage in Commercial Broiler Houses. Presented at the ASABE Annual International Meeting, Paper No. 1009236, Pittsburgh, PA, June 20-23.

Overhults, D.G., I.M. Lopes, G. M. Morello, A. Pescatore, J. Jacob, M. Miller, R. S. Gates, and J.W. Earnest, Jr. 2010. Energy Use in Kentucky Broiler Houses. Presented at the ASABE Annual International Meeting, Paper No. 1009232, Pittsburgh, PA, June 20-23.

Overhults, D.G., G.M. Morello, I.M. Lopes, R. S. Gates, J. W. Earnest, Jr., A. Pescatore, J. Jacob, & M. Miller. 2010. Broiler House Fan Performance. Presented at the ASABE Annual International Meeting, Paper No. 1009240, Pittsburgh, PA, June 20-23.

Overhults, D.G., A. Pescatore, I.M. Lopes, G.M. Morello, J.P. Jacob, M. Miller, J.W. Earnest, Jr., and R.S. Gates. 2010. Air velocities in poultry houses raising large broilers. 2010 Poultry Science Association Annual Meeting. Poultry Science 89(Supp. 1).

Overhults, D.G., A. Pescatore, I.M. Lopes, G.M. Morello, J.P. Jacob, J.W. Earnest, Jr., M. Miller, and R.S. Gates. 2010. Overview of lighting in Kentucky broiler houses. 2010 Poultry Science Association Annual Meeting. Poultry Science 89(Supp. 1).

Overhults, D.G., A. Pescatore, I.M. Lopes, G.M. Morello, J.W. Earnest, Jr., M. Miller, J.P. Jacob, and R.S. Gates. 2010. Using thermal imaging for poultry house energy assessments. International Poultry Scientific Forum, Southern Poultry Science Society Meeting Abstracts, p. 49.

Overhults, D. G. 2010. Broiler Farm Energy Assessments - Take a bite out of rising energy costs. Proceedings of the 2010 North Carolina Broiler Supervisors Short Course. April 15, 2010. Sanford, NC. http://www.ces.ncsu.edu/depts/poulsci/supervisors shortcourse.html.

Overhults, D. G. 2010. All Fans Are Not Created Equal - Cost and management impacts. Proceedings of the 2010 North Carolina Broiler Supervisors Short Course. April 15, 2010. Sanford, NC. http://www.ces.ncsu.edu/depts/poulsci/supervisors shortcourse.html.

Overhults, D. G. 2010. Avoid Obstructions When Installing Attic Inlets. Cheeps and Chirps Newsletter 3(4). Kentucky Poultry Federation, Winchester, KY. web published at URL: http://www.ca.uky.edu/poultryprofitability/Cheeps and Chirps.html

Overhults, D. G. 2010. Adding Tunnel Fans May Increase Static Pressure. Cheeps and Chirps Newsletter 3(4). Kentucky Poultry Federation, Winchester, KY. web published at URL: http://www.ca.uky.edu/poultryprofitability/Cheeps and Chirps.html

Jacob, J. P., M. Miller, A. Pescatore, D. G. Overhults, and R. S. Gates. 2010. Cheeps and Chirps. Newsletter to Kentucky poultry growers. Published quarterly by the Kentucky Poultry Federation, Winchester, KY. Available at http://www.ca.uky.edu/poultryprofitability/Cheeps and Chirps.html.