The dynamics of gas-solid flows and distribution in monolithic multichannel microcirculating fluidized-bed reactors was analyzed using a computational fluid dynamics (CFD) modeling approach. A 2D Euler-Euler multiphase model with the kinetic theory of granular flow has been solved for the detailed monolithic packing geometry. The assemblage of monolithic structured packings with through-flow gas-particulate flows is globally considered in the simulation to capture the dominant mechanisms contributing to the final overall aero/granular dynamics. Due to the complex nature of the interactions between gas and particulate phases and the stationary monolith backbone, one of the challenges in the design and operation of the monolith reactors is the prevention of flow maldistribution. The work presented in this paper forms the basis for a comprehensive reactor-scale model for exploring the intriguing possibilities that the proposed process intensification concept offers for chemical reactions of energy/environmental relevance such as biomass gasification and combustion.