CFD modeling of the influence of carrier thermal conductivity for structured catalysts in the WGS reaction

This work describes a CFD modeling study of the Water Gas Shift single stage process in adiabatic conditions, operated by COMSOL Multiphysics 5.0, by means of two different catalytic configurations; the real novelty was to show that the use of structured catalysts with high thermal conductivity could greatly improve the performances of the whole process. The simulations are then validated with kinetic data reported in a previous work, and provides a useful springboard for the design of a single stage process. It was demonstrated that the use of highly conductive carriers reduces the difference of temperature throughout the catalytic bed, under adiabatic conditions, by means of a backdiffusion of the heat of reaction from the output to the input of the bed. The redistribution allows to increase the inlet temperature, with a benefit for the kinetics, at the expence of the outlet temperature that, decreasing, promotes the thermodynamics. The use of a highly active catalytic formulation, at low temperatures, coupled with a conductive carrier, provides, in principle, the possibility to realize a strong intensification of the process.