First field Demonstration of a Novel Gas-Phase Photo-oxidation Method for Mitigation of Methane, Ammonia, and Odor from Agricultural sources

There is significant climate and environmental benefit to mitigating the environmental impacts of livestock and biogas production. Methane is a strong greenhouse gas that leads to global warming, ammonia emissions pollute groundwater, and odor is a serious local problem which is often regulated. There is a growing focus on the reduction of global methane emissions, including public pledges by countries and food companies. Although some solutions exist for ammonia and odor removal, no scalable method effectively treats methane from enteric fermentation or integrates the mitigation of all three pollutants. It was found that MEPS, utilizing UV-light, chlorine gas and a NaOH scrubber, could remove 98 %, 94 %, and 80 % of methane, ammonia, and hydrogen sulfide (respectively) from the air in a pig barn. Tests in a dairy barn found a quantum yield of 1.54 %, corresponding to a specific energy input of 0.5 kWh/g{CH4}, when operating at a methane removal efficiency of 51 %. While there is much room for optimization of the MEPS process, this work demonstrates an important step in developing scalable technology for eradicating low concentration methane sources from agriculture.