Adsorption-catalytic process for removal of volatile organic compounds from lean waste gases: Optimization of the adsorbent-catalyst bed geometry

Abtstract The study was dedicated to the adsorbent-catalyst bed geometry optimization in the adsorption-catalytic process for the removal of volatile organic compounds (VOC) by means of the mathematical modeling. The commercial software COMSOL Multiphysics was used for the 2D axisymmetric modeling of the process with internal location of the heater, which initiates the self-sufficient adsorbent-catalyst regeneration. The model took into account the adsorption and oxidation reactions on the internal pellet surface, mass transfer between gas flow and catalyst bed, diffusion in the pellets, and heat transfer in the bed. The simulation showed the failure of adsorbent-catalyst regeneration in the cylindrical bed. At the same time, the beds with inlet part in a shape of truncated cone appeared to be much more efficient. The different cone side angles and inflow gas rates were considered by means of mathematical modeling. The optimal geometry parameters for the best process performance were defined in the study.