Energy and cost analysis of organic fertilizer production in Nigeria

Energy study was conducted in an organic fertilizer production plant in Nigeria, to determine the energy consumption patterns and the associated costs for the production of both powdered and pelletised fertilizer. Analysis was conducted for a daily production of 9000 kg of the finished products. Eight and nine defined unit operations were required for production of powder and pellets, respectively. The electrical and manual energy required for the production of powder were 94.5 and 5.6% of the total energy, respectively, with corresponding 93.9 and 5.1% for the production of pellets. The respective average energy intensities were estimated as 0.28 and 0.35 MJ/kg for powder and pellets. The most energy intensive operation was identified as the pulverizing unit with energy intensity of 0.09 MJ/kg, accounting for respective proportions of 33.4 and 27.0% of the total energy for production of powder and pellets. The energy cost per unit production for powdered and pelletised fertilizer using generator were evaluated as ₦2.92 ($0.021) and ₦3.87 ($0.028), respectively, with corresponding values of ₦1.65 ($0.012) and ₦2.00 ($0.014) when electrical energy from the national grid was used. The energy intensities for the production of organic fertilizers were significantly lower than that of inorganic fertilizers.