Computational Fluid Dynamics Simulation of CO2 Methanation in a Fixed-bed Profile Reactor

In this contribution, we present a detailed three-dimensional computational fluid dynamics (CFD) model of a fixed-bed reactor processing the catalytic CO2 methanation reaction. Due to the small tube-to-particle-diameter ratio, particle-resolved CFD simulations are carried out, since they can locally account for transport phenomena, i.e. momentum, heat, and mass transfer. In addition to the interstitial flow simulation, three-dimensional diffusion plus reaction is modelled inside the catalytic pellets. The comparison in terms of axial temperature with a one-dimensional model shows the discrepancy between the models. Additional CFD simulations with different pellet shapes show that the shape has little influence on the heat transfer in these slender fixed-bed arrangements. Experimental results of axial concentration profiles will further validate the CFD model.