(693e) Multi-Scale Simulation of Non-Catalytic Gas-Solid Reactions in Counter-Current Moving-Bed Reactors

Despite the large number of industrial processes involving non-catalytic gas-solid reactions in moving bed reactors, most existing simulations from literature considerably simplify the transport and reaction phenomena involved at the particle scale. In fact, the complex mathematical equation of such systems is derived from the transient characteristics of the solids that affect the local physical properties during the reaction. In this study, a multiscale moving-bed reactor model for non-catalytic gas-solid reactions was developed to evaluate the parameters that hierarchically affect process performance. The model considers the mass, heat, and momentum transport equations for the gas flow in porous medium and the solid particles in counter-current flow, comprising the kinetic model of multiple non-catalytic reactions that occur inside the particles. The reactor and the solid particles are discretized based on the Finite Element Method (FEM) and an extra dimension is used to simulate the particle scale coupled to the reactor scale. The model provides detailed profiles of gas and solid concentration, and temperature along the pellet radius at different reactor positions, as well as solid conversion, gas concentration, and temperature of both phases along the reactor. The multiscale model provides important information into non-catalytic solid reactions, allowing for a direct evaluation of the solid particle characteristics in the performance of industrial reactors.