Azadeh Mirvakili

Ammonium nitrate thermal decomposition in a fluidized bed reactor (FR) is considered as a suitable chemical-free disposal option for the aqueous waste nitrate stream. In this study, operating conditions of ammonium nitrate thermal decomposition are optimized via differential evolution (DE) method to minimize the concentration of ammonium nitrate at outlet of the reactor. The model which is based on two-phase theory of a bubbling fluidized bed, predicts axial concentration profile of all components in the emulsion and bubble phases as well as axial temperature profile of the gas phase. Also the model predictions are in agreement with the experimental data presented by Bhowmick et al (Bhowmick, S., Rao, H., Sathiyamoorthy, D. 2012. Thermal denitration of ammonium nitrate solution in a fluidized-bed Reactor. Industrial and Engineering chemistry research 51: 8394?8403). The optimization results show that ammonium nitrate concentration decreases gradually along the reactor with increasing temperature and gas velocity. This study demonstrates the superiority of optimized fluidized bed reactor (OFR) to FR owing to achieving remarkably lower concentration of ammonium nitrate (about one-fifth times) at the outlet point of the reactor.