Animal solid waste as a potential renewable biomass energy source: a case study of Jordan

Livestock and chicken manures generated in 2017 in Al-Mafraq governorate (North of Jordan) were estimated to be around 250? 103 tons and expected to increase in the coming years. Therefore, the accumulation of animal manures will continue to pose a signifcant threat to public health by direct or indirect exposure. In this work, manures of cow, sheep/goats, and chicken and poultry litter were tested for their chemical composition and thermal characteristics, and then the potential of these manures as valuable renewable energy resources were examined. The proximate and ultimate analyses of these wastes were evaluated along with their heating values. Representative samples of diferent animal manures, chicken feather, and poultry litter were also subjected to a pyrolysis process. Poultry litter had the highest heating value (19.48 MJ/kg) among the tested samples, followed by chicken feathers (18.95 MJ/kg) and sheep/goat (10.92 MJ/kg). Cow manure had the lowest heat value (8.68 MJ/kg). Based on the elemental analysis, poultry waste had the highest contents of carbon and hydrogen, while cow manure had the lowest. Positive correlations were found between the levels of hydrogen and carbon of the selected wastes and their heat values. Poultry litter had a high nitrogen content and a low C:N ratio, whereas cow manure had the lowest nitrogen content and the highest C:N ratio. Poultry manure and litter had a higher volatile matter and a lower ash content than sheep/goat and cow manures. Chicken manure was the best among the tested samples in terms of bio-oil production (36 wt%) followed by poultry litter and sheep/goat manures, while cow manure was the lowest. Poultry litter was found to be the best source for biogas production. It is anticipated that 48.7 million m3 of biogas can be produced annually from the available animal waste resources in this governorate, and this amount of biogas can be converted into energy of about 10.1? 106 GJ. This amount of energy can satisfy the energy demand of at least 5% of the population in the Al-Mafraq governorate. In conclusion, the study recommended that converting animal solid manures to energy would be a promising waste management option or strategy to be applied in this governorate as well as in Jordan.