Feasibility of Extracting Ammonia from Broiler Litter and Scale-Up Considerations

Air inside the broiler litter bed has high ammonia concentrations. The feasibility of extracting ammonia from the broiler litter bed for use as a fertilizer was investigated. Suction was applied to six 1/2-in. (12.7-mm) CPVC pipes with perforations placed 0.15 m below the litter surface in a pen stocked with 150 birds. Litter air was pulled into a phosphoric acid reactor where the ammonia was converted to ammonium phosphate, a fertilizer. Over 51 d, 72.6 g of ammonia was recovered and the pipes did not clog. Ammonia recovery could have been higher had litter ammonia concentrations been comparable with commercial broiler houses. Ammonia removal from the pen did not impact ammonia concentrations above the litter or bird performance. Placing the pipes close to the litter surface where total ammoniacal nitrogen concentrations would have been higher due to fecal loading may have reduced ammonia concentrations in the pen. Litter moisture content was reduced by the ammonia extraction system. A modified scaled-up system may be technically feasible but not cost-effective. Economic feasibility of the system can be improved if pipes placed closer to the surface improve bird performance by reducing in-house ammonia concentrations.