DEM modeling and simulation of a catalytic gas-solid fluidized bed reactor: a spouted bed as a case study

A combined model of discrete element method (DEM) and mass transfer was developed for investigating the local mass transfer throughout a catalytic gas-solid fluidized bed reactor. The mathematical models are based on the equations of mass conservation coupling with the equations of gas and particle motion. The realistic model of DEM, which calculates the contact force acting on the individual particles, is used for monitoring the movement of individual particles in the bed. The contact force is calculated from the concept of spring, dash-pot and friction slider. The flow field of gas is predicted by the Navier-Stokes equation. This DEM-mass transfer model provides the information regarding the particle movement and distribution, gas velocity, gas holdup, and conversion profiles in the bed. A spouted bed reactor for decomposition of ozone on oxide catalyst was chosen as a case study. It was found that the ozone conversion is non-uniform in the bed with very low values near the center but high near the wall. The simulation results show very good agreement with the experimental results of Rovero and co-workers and are in better agreement than the results obtained from the one-dimensional model developed by Mathur and Lim. (C) 2004 Elsevier Ltd. All rights reserved.