Development of Spray-Type Acid Wet Scrubbers for Recovery of Ammonia Emissions from Animal Facilities DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Lara Jane Sebuc Hadlocon Graduate Program in Food, Agricultural, and Biological Engineering The Ohio State University 2014 Dissertation Committee: Lingying Zhao, Advisor Yebo Li Alfred Soboyejo Barbara Wyslouzil Copyright by Lara Jane Sebuc Hadlocon 2014 Abstract Ammonia (NH3) is a pungent, colorless gas that is considered an air quality concern at regional, national, and global scale with huge impacts on the environment, animal, and human health. The expansion of AFOs in the United States significantly increases NH3 emission levels that largely affect air quality inside the barns, within the vicinity of animal operations, and of the ambient air. Among the existing technologies, acid wet scrubbers are promising due to its simple design, low pressure drop advantage on fans, as well as the additional benefit of generating nitrogen fertilizer simultaneously. In this study, a modular spray-type wet scrubber was developed under laboratory conditions by optimizing its design, operating, and environmental parameters. Full-scale scrubbers were designed and developed for long-term field application at a commercial poultry manure composting facility and a deep-pit swine facility. The effluents generated were characterized for its N fertilizer value that would help assess the economic feasibility of the process. The overall scrubber efficiency was then modeled using fundamental understanding of the process to be able to describe the underlying process of gas absorption in an acid spray scrubber. The optimized scrubber module called the Spray Scrubber Module (SSM) was optimized for its nozzle type, scrubber column size and geometry, and number of stages of the spray scrubber module. Effects of operating parameters such as acid concentration, ii superficial air velocity, retention time, and inlet NH3 concentration were quantified. Superficial air velocity adversely affected scrubber performance significantly due to its direct relationship with air residence time. The SSM was optimized as a hexagonal scrubber column with a diameter of 45.72 cm (18 in) equipped with 3 stages of PJ40 spray nozzles, spraying 1% (w/v) H2SO4 scrubbing liquid counter-current to an exhaust air stream with superficial gas velocity of 3 to 4 m s-1 equivalent to air retention times of 0.55 to 0.41 s and was able to recover 91% NH3 at an operating liquid pressure of 0.51 -1 MPa and a superficial air velocity of 4 m s for an inlet NH3 concentration of 30 ppmv operated in single stage of spray nozzle. The optimized SSM was scaled up, resulting to a full-scale acid wet scrubber for a 1.3 m (50 in) exhaust fan of a poultry manure composting facility. The scrubber consists of 15 scrubbing modules with each module equipped with three full cone nozzles operated at an average pressure of 0.59 ± 0.02 MPa -1 and a liquid flow rate of 1.8 L min . This scrubber was able to reduce NH3 by 76% with mean inlet NH3 concentration of 92 ppmv. Another scrubber with a simpler design, with a round geometry and a diameter of 35.56 cm was developed for the swine facility. The scrubber was evaluated to reduce NH3 by 88% with inlet NH3 concentration of 16 ppmv. The scrubber effluents were further characterized for both its nitrogen and elemental content. Characterization study showed that the effluent could reach up to 30% (w/v) ammonium sulfate, which was highly comparable to commercially existing fertilizers. The use of scrubber for fertilizer production would have more economical benefits when applied to poultry farms that have high air flow streams and NH3 concentration. The process of gas absorption using the performance data gathered was also investigated and iii models were developed to describe scrubber performance as a function of important scrubber parameters. This study developed an NH3 mitigation technology in the form of acid spray scrubbers for applications on animal feeding operations in the U. S. It also provided an assessment of both technical and economic feasibility on adopting scrubber technology for NH3 abatement. iv Dedication I dedicate this dissertation to God who is always my source of strength and inspiration. I also offer this to my wonderful parents, Pedro and Angelita Hadlocon whose unwavering support and affection for me brought me this far in my life. v Acknowledgments First, I would like to thank my adviser, Dr. Lingying Zhao for being a great support for me in all aspects as I work for this project. She has given me all opportunities to grow professionally through series of workshops, trainings, and conference proceedings in the field of air pollution control. Her example gave me an inspiration to pursue an academic career as a woman in engineering. I also would like to thank all my committee members for their extra time and support in finishing this dissertation. Prof. Barbara Wyslouzil for sharing her fundamental skills as I develop the theoretical model, Prof. Alfred Soboyejo for his expertise on statistical analysis and modeling, and Dr. Yebo Li for allowing me to use his laboratory to conduct all analyses necessary for my study. Special mention also to the person who started this work, Dr. Roderick Manuzon for personally mentoring me both on the technical and practical side of the scrubber project. His dedication, passion, and perseverance for this work gave me the drive to finish this work until the end. Thanks to the people who taught me that asking for help is not a sign of weakness: FABE staffs, Carl Cooper, the most precise and organized machinist I met who helped me construct a couple of valuable things, Larry Heckendorn for all his welding assistance, and Chris Gecik for his outstanding technical troubleshooting support on all my instrumentation. Also, I would like to thank my fellow FABE graduate vi students, as well as my former lab mates, Shunli Wang and Hui Li for offering their time for this work. I am also indebted to the undergraduate students who helped in the construction of the scrubbers, as well as in conducting field works, Jared Felder, Josh Griffin, Jeff Nazwadi, Anatoliy Meleshchuk, Kyle Schimmoeller, Alan Yost, Bryan Stickel, and Craig Cox. This project is such a joy as I work with several researchers of different backgrounds: to Dr. Ibrahim Elbatawi for being a valuable asset in our field study by retrofitting and improving our field scrubber operation and to Dr. Jungang Dong for helping me gather high-quality field data. I also thank all the people in the extension: the workers and staffs of New Day Poultry Farms: Mark Meyer, Steve, Ynez, Dave, Hesus, and the swine farm owners, Bill and Gail Keck for collaborating with us on this project. Thanks also to the people who turn my challenging graduate school journey into a fun, memorable experience: my friends and church mates in the Filipino Christian Fellowship, FABE Graduate Student Organization, and Filipino Graduate Student Association. Also special thanks to a very dear person: Sanjay Ramdon, my parents: Peter and Bhaby Hadlocon, and my siblings: Lajic, Vincent, Lalaine, and Laargie who have always been my greatest inspirations. vii Vita March 2003 ....................................................Juan Sumulong Memorial Junior College 2008................................................................B.S. Chemical Engineering, University of the Philippines Los Baños 2009 to present ..............................................Graduate Research Associate, Department of Food, Agricultural, and Biological Engineering, The Ohio State University Fields of Study Major Field: Food, Agricultural, and Biological Engineering Specializing in Air Quality and Bio-Environmental Engineering viii Table of Contents Abstract ............................................................................................................................... ii Dedication ........................................................................................................................... v Acknowledgments.............................................................................................................. vi Vita ................................................................................................................................... viii Table of Contents ............................................................................................................... ix List of Tables .................................................................................................................. xvii List of Figures .................................................................................................................. xix Chapter 1: Introduction ...................................................................................................... 1 Chapter 2: Optimization of Ammonia Absorption Using Acid Spray Wet Scrubbers ....... 5 2.1 Introduction ............................................................................................................... 5 2.2. Materials and Methods ............................................................................................. 8 2.2.1. Principle of NH3 absorption in an acid spray wet scrubber ............................... 8 2.2.2. Model for one-stage scrubber performance ..................................................... 11 2.2.3. Model for multi-stage