CFD simulation of continuous non-catalytic gas-solid reaction with uniform particle size distribution

Abstract Non-catalytic fluidized bed reactors (FBRs) have been utilized in various industries. In this study, a computational fluid dynamics (CFD) model, involving a combination of transport processes, intrinsic kinetics, and flow structure, is established and validated to investigate the continuous gas–solid reaction. The simulated results indicate that the solid conversion rate is determined by the solid reaction rate and the mass flow rate. Traditional interphase transfer models have been proven to overestimate the momentum and mass transfer coefficients, and cause deviations in the predicted results. The gas–solid reaction rate, obtained from the structure-based model, depends on reaction time and bed position owing to the variations in the overall reaction rate constant and the non-uniform gas–solid flow structure. The period longer than twice the time required for complete conversion of particle has little effect on the solid conversion process, because of the higher internal diffusion resistance and the wider residence time distribution of particles. The mass transfer during the bubble phase also contributes to the reaction process. Therefore, this study provides a methodology for the CFD simulation of continuous non-catalytic FBRs.