Effect Of Drag Models In Two-Phase Solid-Gas Particles Ceria-Nitrogen: A Hydrodynamic Study Of The Fluidized Bed Reactor

Abstract

- A two-dimensional solid-gas ceria-nitrogen fluidized bed reactor (FBR) used for the thermochemical water splitting process was considered to study the bed hydrodynamics of ceria particles with sphericity 1. Ansys Fluent v19.0 was used for simulation. The numerical model for FBR is validated against the experiment and simulation results conducted with the spherical glass beads of particles size 275 µm from the available literature based on the multi-fluid Eulerian-Eulerian model integrated with the solid particle kinetic theory approach. The simulation results of pressure drop, and simulation and experimental results from the literature for instantaneous voidage and time mean voidage predictions compares well with the literature. The solid-gas ceria-nitrogen with the particle diameter 300 µm was considered for the hydrodynamic study. The effect of different drag models on the expanded bed height was studied. Different drag models Huilin–Gidaspow, Wen-Yu, Syamlal O’Brien, Syamlal O’Brien Para and Gidaspow with the restitution co-efficient of 0.90 were initially used to identify the most appropriate drag model. The simulation results based on different drag models at a fluidization velocity of 0.72 m/s shows that the Syamlal O-Brien will be the most appropriate drag model to study the bed hydrodynamics as it minimizes the overprediction. Then rest of the study was carried out for a range of fluidization velocity 0.24, 0.48, 0.72, 0.96, 1.2, and 1.44 m/s with the Syamlal-O’Brien drag model.