Optimization of Ammonium Nitrate Thermal Decomposition in a Fluidized Bed Reactor Using Differential Evolution (DE) Method

Abstract

Ammonium nitrate thermal decomposition in a fluidized bed reactor (FR) is considered 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 the outlet of the reactor. The model, which is based on the two-phase theory of a bubbling fluidized bed, predicts an axial concentration profile of all components in the emulsion and bubble phases as well as an axial temperature profile of the gas phase. In addition, the model predictions are in agreement with the experimental data presented by Bhowmick et al. (2012). 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 an optimized fluidized bed reactor (OFR) compared to a FR owing to the OFR for achieving a remarkably lower concentration of ammonium nitrate (approximately 20% of the time) at the outlet point of the reactor.

Keywords:

• Ammonium nitrate decomposition
• Differential revolution method
• Fluidized bed
• Optimization
• Thermal denitration