Removing Ammonia Contamination from Biogas Feedstock

Ammonia emissions from swine farms decrease swine productivity, harm the health of surrounding communities, significantly increase pollution, and threaten the production of biogas. A $500M joint venture to develop the largest biogas project in the U.S. is being threatened due to environmental and public health issues associated with the covering of lagoons necessary for the generation of biogas. Swine farms have a history of odor and nuisance problems primarily associated with ammonia emissions. Covering of lagoons has been shown to increase ammonia emissions by approximately 50%, making an already problematic issue even more acute. This project will develop a low cost, reliable, and robust biological treatment system that eliminates most ammonia emissions from swine barns, resolving these pressing issues. There are more than 5,000 swine farms in America with a substantial potential for commercial extraction and production of biogas if the issue of ammonia contamination can be resolved. Development of a system to eliminate the ammonia contamination has been researched for over two decades and while working systems have been previously developed, they are complicated, extremely costly, and thus are not widely adapted. This research will develop a system that is simple, robust, and removes 90% of ammonia emissions from swine facilities, at a quarter of the cost of any existing technology. Phase I research demonstrated the technical feasibility of the proposed system as well as its ease of operation and low cost. All feasibility criteria were met or significantly exceeded, demonstrating that biological acidification of wastewater can effectively suppress ammonia emissions. Phase II research will extend the current testing to further demonstrate applicability of the treatment at fullscale, identify specific costs and benefits, and refine the technology. Field testing will include installation of a system at an industrial swine farm, to demonstrate the full scale performance of the technology. Additionally, Phase II will include completion of further modelling, provide detailed cost and benefit analyses, and valuation of other impact factors such as reduced pollution and improved health. Commercial applications and benefits include increased swine productivity and mitigation of swine facilities’ harmful impacts. Lowering of toxic ammonia levels would benefit the general population by improving health, air quality, and water quality in nearby communities. The capture of methane and carbon dioxide would also reduce greenhouse gas emissions emitted by swine facilities. Treatment of ammonia emissions would also improve public views of biogas, providing support for its use as a ‘green’ alternative. In addition to the financial benefits for swine farmers as they increase productivity, develop biogas to increase revenue, and increase profitability, this technology will have the following societal and environmental benefits: Lower air and water pollution – marked decrease in excess ammonia and nitrogen released to the environment; Improved respiratory health in surrounding communities; Lower greenhouse gas emissions – lower methane and carbon dioxide emissions.