Ammonia emissions from the pig livestock: from a problem to a fertiliser resource

Gas Loop has developed and monitored an air washing system that removes ammonia from the air of the stables, recovering it in an ammonium sulphate solution to increase the animal welfare and productivity due to better air quality inside the pig housing. The pig livestock becomes more sustainable, the ammonia concentration in the rooms where the air is treated by Ammonia Washing Machine is 62% lower than in untreated rooms and the ammonia emissions into the atmosphere are reduced by 54% (ammonia emission avoided for 1,94 kg NH3/animal place per year). The ammonia reduction in the pigsties improves animal welfare, the pig's lungs health and the health of workers. The best breeding conditions increase the feed conversion rate and nitrogen use efficiency. The device draws ammonia rich-air from the stable through suction ducts located below the slatted floor and the air treatment is based on the chemical absorption of ammonia by counter-current acid washing into a tower. The process take place at pH 4.5 and sulfuric acid solution is used as absorbent matrix.