Removing Ammonia, Odor and Dilute Methane from Ventilation Air from Cow, Pig and Biogas Facilities

There is significant interest in mitigating the environmental impacts of cow and pig production, and biogas manufacture. Ammonia emissions pollute groundwater, public agencies regulate odor for obvious reasons, and there is an increased focus on decreasing methane emissions including public pledges by countries and food companies. Many potential solutions are available, with varying cost, complexity, size, and removal efficiency constraints. Here we present the results of a field trial of an innovative new technology, the Methane Eradication Photochemical System (MEPS). Results included demonstrating reduction in ammonia emissions from a pig barn of 94 % of 3 ppm, reduction in the odorous compound hydrogen sulfide from a pig barn of 80 % at 1.5 ppm, and removal of methane from a cow barn of 51 % at 80 ppm. For conditions in a cow barn, the volumetric power input was 171.3 kJ/m3, corresponding to a specific energy input of 0.5 kWh/gCH4. When scaled this result shows that MEPS at its current level of optimization has the potential to destroy methane at a cost of $500/tCO2e, using methane’s 20 year GWP of 80, with the co-benefit of significantly reducing the emission of ammonia and odor.