Source: OHIO STATE UNIVERSITY submitted to
WET SCRUBBERS FOR THE RECOVERY OF NH3 EMISSIONS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0212871
Grant No.
2008-55112-18760
Project No.
OHO01015-SS
Proposal No.
2007-04419
Multistate No.
(N/A)
Program Code
28.0
Project Start Date
Mar 1, 2008
Project End Date
Feb 28, 2013
Grant Year
2008
Project Director
Zhao, L. Y.
Recipient Organization
OHIO STATE UNIVERSITY
1680 MADISON AVENUE
WOOSTER,OH 44691
Performing Department
FOOD, AGRIC & BIOLOGICAL ENG
Non Technical Summary
Ammonia(NH3) emission from agricultural activities has become a significant environmental and public concern as it impacts health, ecosystem acidity, and formation of fine particles (PM2.5). The US EPA has estimated that NH3 emissions from agricultural sources reached 2,418,595 tons in 2002. According to the Fertilizer Institute, the U.S. used 10.4 million metric tons of nitrogen in 2001. As natural gas prices soared from $2.20 to $8 per million Btu last year, significant concerns have been raised about the availability and cost of nitrogen fertilizer for farming. It is time to explore technology for the recovery of nitrogen from agricultural NH3 emissions for fertilizer. The long-term goal of this project is to further develop and demonstrate effective NH3 recovery through gas scrubbing technology. Specifically, we will develop NH3 wet scrubbers for animal buildings, composting facilities, and covered manure storages, determine the performance, maintenance, and operation cost in labs and on farms, develop processes to convert the wet scrubber effluent into nitrogen fertilizer, and disseminate the technology through various existing extension programs and scientific publications. The approaches include design, modeling, lab and field testing, and educational outreach of wet scrubber technology. The outcomes will be optimized wet scrubber design for animal buildings, composting facilities, and covered manure storages; performance and economic information of the wet scrubbers; and increased awareness of various NH3 abatement technologies. The project will contribute to effective NH3 abatement for the protection of environment and conservation of nitrogen resources for the economic competitiveness of the animal production industry.
Animal Health Component
40%
Research Effort Categories
Basic
20%
Applied
40%
Developmental
40%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1333910202010%
1335210202010%
1335399202010%
4023910202010%
4025210202010%
4025399202010%
4033910202010%
4035210202010%
4035399202020%
Goals / Objectives
The long-term goal of this project is to further develop and demonstrate effective NH3 recovery through gas scrubbing technology. Specifically, the project objectives are to: 1. Develop wet scrubbers for ventilation exhausts of animal buildings, composting facilities, and covered manure storage facilities for NH3 emission recovery, 2. Determine the efficacy, long-term performance, maintenance, and operation cost of the wet scrubbers in labs and on commercial farms. 3. Develop processes to convert the wet scrubber effluent into nitrogen fertilizer, and 4. Disseminate and demonstrate the wet scrubber technology and its applications through various existing extension programs and scientific and extension publications
Project Methods
Objective 1. An empirical model of NH3 collection efficiency of the spray wet scrubber, as affected by key design and operating parameters, will be developed using data acquired through the prototype tests and validated experimentally. Scrubbers will be designed for four manure facilities with relatively high NH3 emissions including a layer barn with deep pit, a composting facility, a swine barn with deep pit, and a covered manure storage. Performance of the wet scrubber will be determined by measuring concentrations of gaseous NH3 before and after the wet scrubbers. The design of the spray-type scrubbers for each facility will be further optimized using computational fluid dynamic (CFD) modeling before they are fabricated. The full-scale wet scrubbers will be fabricated at the PI's lab. Objective 2. Two scrubbers will be installed and tested by OSU at a poultry composting facility and a poultry deep-pit building in project year 2, and at a deep-pit swine facility in project year 3. Field test of wet scrubber for a covered manure storage tank will be at the University of Minnesota Southern Research and Outreach Center at Waseca under supervision of Dr. Zhu. The test is planned from June to October during year 2 and 3 when air temperature is sufficiently high for biological activities. The wet scrubber performance and economic data will be collected continuously for at least one month in every season of a year. Scrubber operational data will be recorded to determine the efficacy of each design and estimate the long term performance of the scrubber. Maintenance repairs done on the scrubbers will also be recorded. Data collection, operational inspection, and maintenance task for the scrubbers will be performed weekly. Objective 3. The scrubber effluent will be sampled once per week for sixteen weeks (four weeks per season over a year period) from each field site and delivered to Dr. Li's (co-PI) lab for characterization and experimental conversion to various grades of ammonia sulfate fertilizer. Processes such as reverse osmosis, electro-dialysis, and evaporation will be tested. Objective 4. This project is an integrated project. The research findings and related science based information will be disseminated through development and delivery of extension programs and publications. The extension publications include PowerPoint presentations, fact sheets, bulletins, and popular press article. The extension materials will be reviewed and published through the OSU Extension and the University of Minnesota Extension Service. The credibility of the project findings will be established through publication of peer-reviewed journal articles.

Progress 03/01/08 to 02/28/13

Outputs
Target Audience: The target audiences are animal farmers, air mitigation industry, researchers, extension educators, regulatory agencies, and the general public. The stakeholders of this project are AFO producers, crop producers, environmental professionals, extension educators, air pollution mitigation researchers, and environmental policy makers. Changes/Problems: The project was delayed due to the difficulties encountered during the field tests. Many difficulties were encountered during field operations of the wet scrubbers, including pump failure, clogging of nozzles and water filters, frozen conditions, equipment failure due to high moisture and cold environments, and interference of rain water with mass balance of the scrubber liquid recycling measurement. Gradually, the challenges were resolved. The pumps were replaced with seal-less magnetically driven gear pump with high chemical resistance. Protocols for scrubber maintenance were changed to increase frequency of de-clogging the nozzles, cleaning the water filter, and replacing the air filters. Heavy duty self-regulating heat tapes were installed on all pipelines during winter to avoid freezing during extreme weather conditions. A cap was build for the scrubber to exclude rainwater falling into the scrubber for water balance tracking. Electrical fluctuations and power failure at commercial farms due to weather condition were still observed. Some data were missing due to the power and equipment failure. However, through an extension of the project and a longitudinal field test period, the objectives of the project have been fully completed. What opportunities for training and professional development has the project provided? Two workshops on “Ammonia (NH3) Emissions and Nitrogen Conservation” and “Mitigating Ammonia (NH3) Emissions from Poultry Facilities for Fertilizer” were developed and conducted in May of 2011 and September of 2012, respectively. One field demonstration of the wet scrubber operation was organized in 2012 as well. The workshop and field demonstration had been digitized to form online workshops (airquality.osu.edu) for producers, extension educators, agency professionals, technical consultants, and researchers who was not able to attend the workshops and field demonstratio. How have the results been disseminated to communities of interest? The project results were presented at several extension conferences, the annual meetings of American Society of Agricultural and Biological Engineers, and one annual conference of Air and Waste Management. One journal article, one symposium paper, one factsheet have been polished. Several journal articles have been drafted for submission. Two workshops on “Ammonia (NH3) Emissions and Nitrogen Conservation” and “Mitigating Ammonia (NH3) Emissions from Poultry Facilities for Fertilizer” were developed and conducted in May of 2011 and September of 2012, respectively. One field demonstration of the wet scrubber operation was organized in 2012 as well. The workshop and field demonstration had been digitized to form online workshops (airquality.osu.edu) for producers, extension educators, agency professionals, technical consultants, and researchers who was not able to attend the workshops and field demonstration What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? In reference to the project objectives, the followings have been accomplished. Wet scrubber prototypes had been designed and fabricated. A scrubber instrumentation, data acquisition and control system wasdeveloped for monitoring scrubber performance data such as inlet and outlet air ammonia concentration, scrubber liquid pH and electrical conductivity, air and liquid temperature, liquid flow rate. Experiments were conducted to test the effect of scrubber design and operating parameters on ammonia collection efficiency. The performance of eight nozzles was tested for the effects of operating pressure, liquid flow rate, droplet size and spray angle. The best performing nozzles were selected. The effects of superficial air velocity, acid concentration, nozzle position, inlet ammonia concentrations and operating temperature were tested using the two best performing nozzles selected. Initial examination of the resultsshowed that aside from operating pressure, liquid flow rate and droplet size, the spray height and spray angle significantly affect wet scrubber performance. The nozzle position had no significant effect on ammonia absorption performance. It wasverified that 1% w/v sulfuric acid concentration of the scrubbing liquid was the optimum to get the highest ammonia collection performance. The most significant result was obtained by testing the effect of air velocity, which showed that the wet scrubber performance improved from 70% to 97% by decreasing the superficial air velocity from 5.3 m/s to 2 m/s at a typical inlet ammonia concentration of 30 ppm. With a full air speed of 5.3 m/s, increased inlet ammonia concentrationsdecreased ammonia scrubbing performance from 90% at 10 ppm inlet ammonia concentration to 34% at 400 ppm inlet ammonia concentration. Empirical and mathematical models for scrubbing liquid performance of the nozzleswere developed. Three full-scale wet scrubbers were designed based on the air flow rate and NH3 loading rate of the exhausts from the selected sites: site A: swine manure storage facility; site B: poultry manure composting house, and site C: deep-pit swine barn. The scrubbers were installed and longitudinally tested in the commercial farms. The wet scrubbers performance data, operation condition and cost data, and maintenance cost data were collected and analyzed. Economical analysis of the wet scrubber operations were conducted. The wet scrubber field tests were completed and results showed the following field performances: At the covered manure storage facility with a flow control of 10-15 L/min, a removal efficiency ranging from 20% to 60% was observed at inlet NH3 concentration of 8 ppmv to 137 ppmv during the 40-day operation. Deep-pit swine scrubber performance was evaluated for summer, fall, winter, and spring showing weighted mean efficiencies of 94.80%, 78.21%, 76.90%, and 96.76% at average inlet NH3concentrations of 10.92 ppmv, 23.1 ppmv, 25.41 ppmv, and 5.39 ppmv. The poultry manure composting scrubber was evaluated chronologically-ordered for winter, spring, summer, and fall season with weighted mean efficiencies of 67.90%, 80.71%, 67.99%, and 63.09% at average inlet NH3 concentrations of 137.61 ppmv, 62.33 ppmv, 67.32 ppmv, and 61.19 ppmv, respectively. All wet scrubber terminal effluents generated during the entire operation were analyzed for NH3-N content and presence of trace elements. The effluent characteristics wereevaluated to determine the effective and safe use of the effluent as fertilizer. On average, there was about 9.25% and 30.27% ammonium-sulfate fertilizer produced from the swine and poultry scrubber operation, respectively, while existing commercial fertilizer grade ranged from 22-54% of ammonium-sulfate. Without much post process, the effluent is close to the commercial grade fertilizer. However, the pH of the effluents need to be adjusted before land application. An alternative use of the effluents to enhance fertilizer value of compost or manure shows needs to be explored. The swine operation required longer time of operation due to relatively low inlet NH3 concentrations being scrubbed off. Poultry scrubber operation was found to be more promising in NH3 recovery with both efficacy and economics weighed in. Preliminary economic analysis showed that scrubbers for swine finishing facility and poultry manure composting facility would need one (5) yrs and five (1) yr of continuous operation, respectively to break even with total fixed costs and operational and maintenance costs. The fertilizer generated by the process will enhance farm income or reduce the needs for purchasing commercial nitrogen fertilizer. The project results were presented at several extension conferences, the annual meetings of American Society of Agricultural and Biological Engineers, and one annual conference of Air and Waste Management. One journal article, one symposium paper, one factsheet have been polished. Several journal articles have been drafted for submission. Two workshops on “Ammonia (NH3) Emissions and Nitrogen Conservation” and “Mitigating Ammonia (NH3) Emissions from Poultry Facilities for Fertilizer” were developed and conducted in May of 2011 and September of 2012, respectively. One field demonstration of the wet scrubber operation was organized in 2012 as well. The workshop and field demonstration had been digitized to form online workshops at airquality.osu.edu. The project contributed greatly toward development offeasible wet scrubbers for scrubbing and recovering ammonia emissions from poultry buildings and composting facilities and swine manure storages. The results clearly indicate that the spray scrubber design is highly capable of removing ammonia emissions from animal facilities. The project has resulted in a new technology for collecting ammonia emissions from AFOs using acid NH3 spray scrubbers at high speed low pressure drop axial fans, which are typically used in animal facilities in the U.S.. The study developed optimized spray wet scrubbers for recovery of ammonia emissions from animal manure storage facilities and production of nitrogen fertilizer. The wet scrubbers remove NH3 and enable producers to mitigate significant environmental impacts of ammonia emissions from AFOs while producing nitrogen fertilizer for crop production. The fertilizer generated by the process will enhance farm income or reduce the needs for purchasing expensive commercial nitrogen fertilizer. The overall impact of the study is to provide the animal industries an effective ammonia mitigation tool to reduce their environmental impact while harvesting ammonia as an alternative source of nitrogen fertilizer.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Hadlocon L.S., L. Y. Zhao, R.B. Manuzon, and I.E. Elbatawi. 2012. Field Evaluation of a Spray Wet Scrubber for Mitigation of Ammonia (NH3) Emission from the Pit Exhaust of a Deep-Pit Swine Facility. Presentation at the 2012 ASABE Annual International Meeting.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2011 Citation: Hadlocon L.S., L. Y. Zhao, and R.B. Manuzon. 2011. A Spray Wet Scrubber for Mitigation of Ammonia (NH3) Emissions from the Pit Exhaust of a Deep-Pit Swine Facility. Presentation at the 2011 ASABE Annual International Meeting.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2011 Citation: Zhao, L.Y., R.B. Manuzon, and L.S. Hadlocon. 2011. Field Evaluation of a Wet Scrubber for Recovering Ammonia (NH3) Emissions from a Poultry Manure Composting Facility for Nitrogen Fertilizer. Presentation at the 2011 ASABE Annual International Meeting.
  • Type: Journal Articles Status: Published Year Published: 2011 Citation: Fu, G. M., Cai, T., Li, Y. B. 2011. Concentration of ammoniacal nitrogen in effluent from wet scrubbers using reverse osmosis membrane. Biosystems Engineering. Vol. 109, no. 3. : 235-240. (IF: 0.983)
  • Type: Other Status: Published Year Published: 2011 Citation: Manuzon,R., Zhao, L.Y., Jonjak,A. 2011. Wet scrubber for mechanically ventilated animal facilities. Extension Factsheet. http://www.extension.org/pages/15538/air-quality-in-animal-agriculture.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2009 Citation: Manuzon, R.B. and L. Y. Zhao, 2009. Are wet scrubbers applicable for controlling ammonia and particulate emissions from AFOs - A Review. Accepted for publication at the 2009 AWMA Annual Conference Symposium
  • Type: Journal Articles Status: Other Year Published: 2013 Citation: Hadlocon L.S., L. Y. Zhao, R.B. Manuzon, J. Dong and I.E. Elbatawi. 2013. Development and Evaluation of a Spray-Type Acid Wet Scrubber for Mitigation of Ammonia Emission from Deep-Pit Swine Facilities. In Preparation.
  • Type: Journal Articles Status: Other Year Published: 2013 Citation: Hadlocon L.S., L. Y. Zhao, R.B. Manuzon. 2013. Development and Evaluation of a Spray-Type Acid Wet Scrubber for Mitigation of Ammonia Emission from a Commercial Poultry Manure Composting Facility. In Preparation.
  • Type: Journal Articles Status: Submitted Year Published: 2013 Citation: Lin, H., X. Wu, C. Miller, J. Zhu, L. J. Hadlocon, R. Manuzon, L. Y. Zhao. Pilot-scale field study for ammonia removal from lagoon biogas using an acid wet scrubber. Submitted to Journal of Environmental Quality in Feb. 2013.
  • Type: Journal Articles Status: Other Year Published: 2013 Citation: Hadlocon L.S. and L. Y. Zhao. 2013. Characterization of Wet Scrubber Effluents from Swine and Poultry Facilities for Land Application as Nitrogen Fertilizer. In Preparation.
  • Type: Journal Articles Status: Other Year Published: 2013 Citation: Hadlocon L.S. R.B. Manuzon,and L. Y. Zhao. 2013. Modeling NH3 absorption using spray acid wet scrubber technology. In Preparation.


Progress 03/01/11 to 02/28/12

Outputs
OUTPUTS: The project's fourth year of operation was focused on long-term seasonal testing of the optimized acid spray wet scrubbers at actual animal manure storage facilities. Some challenges encountered during the start-up phase were resolved: Pump was replaced with seal-less magnetically driven gear pump with high chemical resistance. Protocols for scrubber maintenance were changed to increase frequency of de-clogging the nozzles, cleaning the water filter, and replacing the air filters. Instruments were enclosed with air-tight electrical boxes to avoid interference of moisture and dust. Heavy duty self-regulating heat tapes were installed in all pipelines during winter to avoid freezing during extreme weather conditions. Scrubber operations for both swine and poultry facilities are ongoing. Scrubber for the deep-pit swine facility was officially started to collect seasonal data in June 2011 and was run continuously for 19-30 days each season. To date, swine scrubber performance was evaluated for summer, fall, and winter, showing weighted mean efficiencies of 94.80%, 78.21%, and 76.90% at average NH3 concentrations of 10.92 ppmv, 23.1 ppmv, and 25.41 ppmv. The scrubber installed for the poultry composting facility underwent lengthy troubleshooting and was just officially started to collect data in August 2011. Fall and winter operation showed performance values of 63.09% and 67.90% at inlet NH3 concentrations of 61.10 ppmv and 137.61 ppmv, respectively after 10 days of continuous operation. The performance tests for the scrubber designed for manure storage has been completed. Ammonia workshop entitled " Ammonia (NH3) Emissions and Nitrogen Conservation" was organized in May of 2011. Two presentations on wet scrubber technology given at 2011 ASABE Annual International Meetings. PARTICIPANTS: Dr. Lingying Zhao, Dr. Yebo Li, Mr. Roderick Manuzon, Ms. Lara Jane Hadlocon, and Mr. Jon Rausch, Department of Food, Agricultural, and Biological Engineering, The Ohio State University Dr. Jun Zhu, Bioproducts & Biosystems Engineering Department, University of Minnesota. TARGET AUDIENCES: animal farmers, air mitigation industry, researchers, extension educators, regulatory agencies, and the general public. The stakeholders of this project are AFO producers, crop producers, environmental professionals, extension educators, air pollution mitigation researchers, and environmental policy makers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The study developed aimed to optimize wet scrubber and evaluate its actual performance in animal manure storage facilities to recover NH3 emissions. The data gathered from field operation will provide a solid understanding of the scrubber performance under actual application conditions of animal facilities. The field tests will also help collect data on maintenance and operational costs and benefits gained from recovering NH3 as fertilizer, which will used to analyze the economics of the scrubber operation. The overall impact of the study is to provide the animal industries an effective ammonia mitigation tool to reduce their environmental impact while harvesting ammonia as an alternative source of nitrogen fertilizer. Preliminary economic analysis showed that scrubbers for swine finishing facility wwould need 5 years and poultry manure composting facility would need one year of continuous operation, to break even with total fixed costs, operational and maintenance costs. Ammonia workshop entitled "Mitigating Ammonia (NH3) Emissions from Poultry Facilities for Fertilizer" was also developed and held in September 2012.

Publications

  • No publications reported this period


Progress 03/01/10 to 02/28/11

Outputs
OUTPUTS: The project's third year of operation was focused on development and field testing of full-scale wet scrubbers. The scrubber for a poultry composting facility was delivered in July 2010 and had gone through a lengthy troubleshooting period. The scrubber for a deep-pit swine facility was installed in December of 2010. Many difficulties were encountered during field operations of the wet scrubbers, including pump failure, clogging of nozzles and water filters, frozen conditions, equipment failure due to high moisture and cold environments, interference of rain water with mass balance of the scrubber liquid recycling measurement, and leakage of the wet scrubber. After a lengthy trouble shooting period, the swine scrubber started normal operation in June of 2011 and the poultry scrubber in August of 2011. Tests are ongoing. Preliminary results showed that the scrubber for the poultry composting facility has an efficiency of about 80% when the scrubbing liquid is recycled continuously for 1-2 week and the ammonium sulfate concentration increases to about 12% w/v. The scrubber in the swine pit facility has an efficiency range of 80 to 95% when the scrubbing liquid is recycled for about one month, ie. the ammonium sulfate concentration is 12%. The performance tests of the scrubber for a manure storage at University of Minnesota has been completed. Data analysis is on-going. The performance tests for the swine building and poultry composting facilities at Ohio are on-going will continue till next July to collect sufficient data. A workshop on "Ammonia emission and nitrogen conservation" was developed and organized in May of 2011. Two presentations entitled "A Spray Wet Scrubber for Mitigation of Ammonia (NH3) Emission from the Pit Exhaust of a Deep-Pit Swine Facility" and "Field Evaluation of a Wet Scrubber for Removal of Ammonia Emissions from a Poultry Manure Composting Facility for Nitrogen Fertilizer" were presented during the 2011 ASABE Annual meeting. PARTICIPANTS: Dr. Lingying Zhao, Dr. Yebo Li, Mr. Roderick Manuzon, Ms. Lara Jane Hadlocon, and Mr. Jon Rausch, Department of Food, Agricultural, and Biological Engineering, The Ohio State University Dr. Jun Zhu, Bioproducts & Biosystems Engineering Department, University of Minnesota. TARGET AUDIENCES: The target audiences are animal farmers, air mitigation industry, researchers, extension educators, regulatory agencies, and the general public. The stakeholders of this project are AFO producers, crop producers, environmental professionals, extension educators, air pollution mitigation researchers, and environmental policy makers. PROJECT MODIFICATIONS: This project period was extended till Feb. 2012

Impacts
The study developed optimized spray wet scrubbers for recovery of ammonia emissions from animal manure storage facilities and production of nitrogen fertilizer. The wet scrubbers remove NH3 (80% efficiency) and enable producers to mitigate significant environmental impacts of ammonia emissions from AFOs while producing nitrogen fertilizer for crop production. Simulated recycling studies results showed that scrubber can be operated to concentrate scrubbing liquid of up to 30% ammonium sulfate, a fertilizer grade. The fertilizer generated by the process will enhance farm income or reduce the needs for purchasing expensive commercial nitrogen fertilizer.

Publications

  • Fu, G. M., Cai, T., Li, Y. B. 2011. Concentration of ammoniacal nitrogen in effluent from wet scrubbers using reverse osmosis membrane. Biosystems Engineering. Vol. 109, no. 3. : 235-240. (IF: 0.983)
  • Manuzon,R., Zhao, L.Y., Jonjak,A. 2011. Wet scrubber for mechanically ventilated animal facilities. Extension Factsheet. http://www.extension.org/pages/15538/air-quality-in-animal-agricultur e.


Progress 03/01/09 to 02/28/10

Outputs
OUTPUTS: The project's second year of operation was focused on development, scale-up and field testing of full-scale wet scrubbers. Three wet scrubbers were designed based on the air flow rate and NH3 loading rate of the exhausts from the selected sites: site A: swine manure storage facility; site B: poultry manure composting house, and site C: deep-pit swine barn. The scrubber in site A was installed in fall 2009, went though troubleshooting processes, and is currently being operated. It is composed of a 6 in diameter vertical spray scrubber which is capable of capturing 95% to 99% NH3 ranging 100 to 200 ppm with 100 to 200 scfm biogas flow. The cost of developing this scrubber is $4,000 per lagoon exhaust. The scrubber in site B was delivered in July 2010 and is currently being installed. This scrubber was scaled up based on module developments whose geometry was optimized by CFD to ensure even flow distribution. The scrubber, consisting of 15 modules, is expected to remove about 80% of 200 ppm NH3 at the exhaust fans (54 inch in diameter and 18,000 scfm). The cost of developing this scrubber is $13,000 per fan. Data seems to show that collecting highly concentrated ammonia at exhausts of composting houses would result in profitable operation. The scrubber at Site C is being constructed and will be installed at a deep-pit swine barn in Ohio in late August. The work for the next stage will include field testing the wet scrubbers, collecting and analyzing data; conducting economical analysis of the wet scrubber operations, publishing the research findings, and developing extension/education materials, workshops, and extension education programs. PARTICIPANTS: Dr. Lingying Zhao, Dr. Yebo Li, Mr. Roderick Manuzon, Ms. Lara Jane Hadlocon, and Mr. Jon Rausch, Department of Food, Agricultural, and Biological Engineering, The Ohio State University Dr. Jun Zhu, Bioproducts & Biosystems Engineering Department, University of Minnesota TARGET AUDIENCES: The target audiences are animal farmers, air mitigation industry, researchers, extension educators, regulatory agencies, and the general public. PROJECT MODIFICATIONS: The project was started on July 1, 2008.

Impacts
The study provided solid understanding on the design and testing methods for developing acid NH3 spray scrubbers for high speed low pressure drop axial fans, which are typically used in animal facilities in the U.S.. Preliminary tests had shown that the scrubbers will effectively recover 80-99% of ammonia emissions from animal manure storage facilities. Simulated recycling studies results showed that scrubber can be operated to concentrate scrubbing liquid of up to 30% ammonium sulfate, a fertilizer grade which is suitable for direct field application. The fertilizer generated by the process will enhance farm income or reduce the needs for purchasing commercial nitrogen fertilizer.

Publications

  • Manuzon, R.B. and L. Y. Zhao, 2009. Are wet scrubbers applicable for controlling ammonia and particulate emissions from AFOs - A Review. Accepted for publication at the 2009 AWMA Annual Conference Symposium


Progress 03/01/08 to 02/28/09

Outputs
OUTPUTS: The project was started on July 1, 2008. A new fourteen-inch diameter wet scrubber prototype was designed and fabricated for conducting well controlled fundamental spray nozzle parametric studies. A 24" diameter wet scrubber prototype was restored for conducting scrubber liquid recycling experiments and will also be used in the design scale-up stage of the project. An improved scrubber instrumentation, data acquisition and control system was also developed for monitoring scrubber performance data such as inlet and outlet air ammonia concentration, scrubber liquid pH and electrical conductivity, air and liquid temperature, liquid flow rate. An improved ammonia-air mixing chamber which had better airflow control was also designed for the 14" prototype scrubber. Experiments were conducted to test the effect of scrubber design and operating parameters on ammonia collection efficiency. The performance of eight nozzles in an environment controlled laboratory experiment was tested for the effects of operating pressure, liquid flow rate, droplet size and spray angle. The best performing nozzles were selected. The effects of superficial air velocity, acid concentration, nozzle position, inlet ammonia concentrations and operating temperature were tested using the two best performing nozzles selected. Initial examination of the results also showed that aside from operating pressure, liquid flow rate and droplet size, the spray height and spray angle significantly affect wet scrubber performance. The nozzle position had no significant effect on ammonia absorption performance. It was also verified that 1% w/v sulfuric acid concentration of the scrubbing liquid was the optimum to get the highest ammonia collection performance. The most significant result was obtained by testing the effect of air velocity which showed that the wet scrubber performance improved from 70% to 97% by decreasing the superficial air velocity from 5.3 m/s to 2 m/s at a typical inlet ammonia concentration of 30 ppm. With a full air speed of 5.3 m/s, increased inlet ammonia concentrations resulted decreased ammonia scrubbing performance from 90% at 10 ppm inlet ammonia concentration to 34% at 400 ppm inlet ammonia concentration. Empirical and mathematical models for scrubbing liquid performance of the nozzles are currently being developed. Calibrated nozzle flow rates and droplet size distribution data was collected. Experiment studies on effects of multi-staging on the ammonia scrubber performance have also been conducted. Dr. Yebo Li has set up the lab scale membrane filtration unit for the concentration of ammonia. The membrane system is working now. Dr. Jun Zhu has completed the preparatory work for the project, which include 1) purchasing ammonia monitoring equipmenT, 2) searching for a cover for the manure storage at the University of Minnesota Southern Research and Outreach Center, and 4) drafting the test protocols for the upcoming experiments as soon as the cover is shipped to the site and installed. PARTICIPANTS: Dr. Lingying Zhao, Dr. Yebo Li, Mr. Roderick Manuzon, Ms. Lara Jane Hadlocon, and Mr. Jon Rausch, Department of Food, Agricultural, and Biological Engineering, The Ohio State University Dr. Jun Zhu, Bioproducts & Biosystems Engineering Department, University of Minnesota TARGET AUDIENCES: The target audiences are animal farmers, air mitigation industry, researchers, extension educators, regulatory agencies, and the general public. PROJECT MODIFICATIONS: The project was started on July 1, 2008. The research associate was officially hired to work on the project at that date.

Impacts
The project contributed greatly to develop feasible wet scrubbers for scrubbing and recovering ammonia emissions from poultry buildings and composting facilities and swine manure storages . The well controlled laboratory experiments on the prototype spray scrubber enabled us to develop fundamental understanding on effects of design and operating parameters of spray wet scrubber on ammonia removal. Optimized design of effective wet scrubbers will fully rely on the fundamental experimental study results and the empirical and mathematical models developed latter. The preliminary laboratory optimization study showed an ammonia collection efficiency of up to 70% for one stage wet scrubbers at full air speed of 5 m/s and 97% at air speed of about 2 m/s. The results clearly indicate that the spray scrubber design is highly capable of removing ammonia emissions from animal facilities. The current findings are being investigated for further optimization using multi-nozzle arrangements and slower air velocity operations. The project has therefore a very high potential for developing a new technology for a design of a low pressure drop and high speed wet scrubber for collecting ammonia emissions from AFOs. A comprehensive mathematical tool for predicting ammonia wet scrubbing performance is currently being developed which would enable effective mitigation of ammonia emissions from animal facility.

Publications

  • Manuzon, R.B.and L. Y. Zhao, 2009. Are wet scrubbers applicable for controlling ammonia and particulate emissions from AFOs: A Review. Accepted for publication at the2009 AWMA Annual Conference Symposium.