Removing ammonia contamination from biogas feedstock

As biogas projects based on animal manure become a large-scale reality, unintended consequences arise from ammonia laden wastewater used as a feedstock for biogas production. While carbon capture and conversion to biogas is maximized in covered lagoons, covering of lagoons doubles ammonia emissions in barns, damaging swine health and productivity and increasing nuisance ammonia emissions that reach surrounding neighborhoods. Removal of ammonia from swine wastewater biogas feedstock is necessary to ensure that swine lagoons can be used to produce biogas. The leading swine producer has recently committed $500M in a joint venture to produce biogas from several hundred of its swine lagoons which will make the project the largest biogas generator in the U.S. However, there is concern that this project may be in jeopardy if ammonia contamination is not addressed. Pancopia will determine the feasibility of removing ammonia from swine wastewater. Effluent from swine lagoons containing high ammonia concentrations will be treated in a pilot bioreactor to convert the ammonia to nitrate and nitrite and lowering the pH to keep the remaining ammonia from coming out of solution. This low ammonia, high nitrate/nitrite wastewater will be used in a simulated swine cesspit to remove nitrogen and suppress ammonia gas emissions. Proof of concept will permit Pancopia to expand this system to a full-scale treatment unit at a commercial swine farm during Phase II of the project. Successful development of a system to remove ammonia contamination in manure-based biogas feedstock will permit agricultural-sourced biogas projects to expand rapidly. There are more than an estimated 8,000 potential agricultural biogas projects that would benefit from this advancement.