Enhancing the biomethanation of poultry litter by improving the carbon nitrogen ratio of the feedstock

Abstract

Poultry breeding plays a significant role in the livelihood of the rural community in a country like India In India the poultry sector accounts approximately 1 for the nations GDP The livestock breeding contributes to the reactive solid waste dispersal which influence the spreading of diseases eutrophication etc On another hand the poultry farms require enormous amount of electrical energy for heating, lighting and humidifying which is extracted out of the public electric grid At this juncture of acute energy shortage across the globe the energy demands from the poultry farms questions the self sustainability of the farms This lacuna attracts the researchers to find a solution for the effective solid waste management of the poultry wastes in turn substantiate the energy demands of the farms Disposing the poultry litter gain more attention as the accumulation of the litter is increasing due to the enormous growth of poultry sector Many researchers suggested that the biological treatments are best way to manage the poultry litter by mitigating its environmental impacts and thereby producing useful combustible energy out of the wastes Among biological treatments anaerobic digestion is proven energy producing process to generate gaseous fuel and at the tail end which converts the waste into a non reactive nutrient rich organic manure Even though the potential of biogas technology is vast there are some hitches associated with the anaerobic digestion of poultry wastes The anaerobic digestion of poultry wastes results in excess accumulation of ammonia in the form of free ammonia NH3 and ammonium ion NH4 inside the digester Even though ammonia is an essential nutrient for the micro organisms to survive it causes inhibition to the process when it exceeds the threshold limit which is 0 7g L to 2 6gL The accumulation of ammonia is due to the excess nitrogen present in the poultry litter to process the poultry litter efficiently by anaerobic digestion the primary inhibiting factor Carbon-Nitrogen ratio of the PL should be improved In this research the emphasis was given to improve the Carbon- Nitrogen C/N ratio thereby enhancing the biomethane yield newline