Numerical study of the gas–solid flow pattern in methanol to olefiens fluidized bed reactor: Cold model

Abstract

AbstractIn the present study, the hydrodynamic behaviour of a three‐dimensional bubbling fluidized bed reactor was studied using the finite volume method and granular kinetic theory. The effect of two types of gas distributors (i.e., perforated and porous plates) on the gas/solid hydrodynamic was investigated. The residence time distribution model was utilized to check the deviation of the gas flow pattern from the ideal flow patterns for two types of distributors. The parameters indicating the degree of back‐mixing, such as mean residence time and dimensionless variance, were calculated. Also, the model was verified through the comparison of the particle velocity with experimental data obtained by the particle image velocimetry–digital image processing (PIV‐DIA) technique. It was found that the gas flow pattern in the present bubbling fluidized bed is closer to the mixed flow than the plug flow pattern. It was also found that the porous plate distributor gives more uniform hydrodynamic distributions of gas and solid in the bed, which results in better gas–solid mixing due to the formation of the smaller bubbles.