Energy use and economic analysis of NPK-15:8:15 fertilizer granulation process in Iran

Ratio of 15:8:15 (15% nitrogen, 8% phosphorus and 15% potassium) is the dominant ratio of NPK fertilizers in Iran. The aim of this present paper was to study the energy consumption of the NPK-15:8:15 granulation process, and economic analysis of NPK-15:8:15 fertilizer granulation process. For this purpose, the data on 8 NPK-15:8:15 fertilizer plants by monthly for 3 months (February, May and August) in 2014, were collected and analysed. The results indicated that a total energy input of 1659.92 MJ ton−1 was consumed for NPK-15:8:15 fertilizer granulation process. Electricity (with 92.05%) was the highest energy inputs for NPK-15:8:15 fertilizer granulation process. The results indicate that 0.47 and 99.53 of the total energy input were in renewable and non-renewable forms, respectively. The regression results revealed that the contribution of energy inputs on yield process (except electricity and human labour energies) was significant. The natural gas had the highest impact (0.71) among the other inputs in NPK-15:8:15 granulation process. Economic analysis indicated that the total cost of process for one ton of NPK-15:8:15 fertilizer was around 9.05 $.