Simulation and Optimization of Operating Conditions of a Packed Bed Reactor for Acrylonitrile Production from Propene Ammoxidation over α-Bismuth Molybdate

Propene ammoxidation is a complex reaction with acrylonitrile (ACN) as a desired product and several undesired products such as CO2 and CO. Optimization of this process is important to meet the sustainable development goals by reducing the generation of greenhouse gasses and energy required to purify ACN. In this work, propene ammoxidation over alpha-bismuth molybdate in a packed bed reactor (PBR) is simulated with Mathematica to maximize the ACN yield. A system of ordinary differential equations (ODEs) is set based on kinetics and mechanism of propene ammoxidation. Four different levels of temperature, pressure, oxygen to propene ratio, water to propene ratio, and pellet size are selected. Then, 16 runs are defined based on the modified L-16 orthogonal array of Taguchi method and the system of ODEs is run to find the mole flow rates of all species and pressure drop. These results are used to maximize the ACN yield using the analysis of variance and signal to noise ratios. The results indicate that temperature and pellet size are, respectively, the most and the least important parameters to maximize the ACN yield. The PBR must work under the maximum possible temperature and minimum possible pressure. Using the optimum operating conditions, an overall propene conversion of 98% and acrylonitrile yield of 76% is achieved.