Evaluation of biogas production estimates through anaerobic digestion using laying hens waste

Abstract

Poultry activity is very important for the economy of Mozambican families. However, it generates large amounts of residual biomass that, if not properly treated, can have a high polluting potential and cause serious environmental impacts. The study aimed to evaluate whether the waste from laying hens can constitute a technologically and economically viable alternative for the production of energy through anaerobic digestion. To achieve the aim of this study, samples were collected in three aviaries belonging to Agro-pecuária e Avícola Abílio Antunes company located in the district of Gondola-Province of Manica, Mozambique. Residual biomass of laying hen manure was considered optimal with water content of 71%, temperature 29 °C, electrical conductivity 9.83 mS cm^-1 and pH 7.58. The volume of biogas, biofertilizer and carbon credits was converted into monetary values, thus generating an annual revenue of approximately 1,228,873,504.97 Meticais. The average annual cost of maintaining and operating the biodigester system is approximately 118,948,995.72 Meticais. The economic return was positive from the third year onwards and the Net Present Value (NPV) was 3,944,554,866.46 Meticais, with an Internal Rate of Return (IRR) of 37% over the ten-year period. Thus, the project proved to be economically and environmentally viable, despite the high investment value.