Experimental and modeling study of volatile organic compounds adsorption over zeolitic monolith adsorbent

Abstract

In this study, a coupled mass and momentum model is developed and solved to describe the dynamic adsorption of a single adsorbate over honeycomb structured zeolite under industrial operating conditions. The Linear Driving Force approximation was used to predict the kinetics of adsorption to the solid-phase mass transfer and Navier Stokes equations were solved both radially and axially under laminar flow conditions through the honeycomb channels. To investigate the effect of key input parameters on model results, a sensitivity analysis was performed. Modeling and experimental results compared the effects of different initial concentrations and gas stream face velocities under a range of conditions to determine adsorption capacity, removal efficiency, and the 5% breakthrough time. Overall, the model output was in good agreement (less than 5% mean absolute relative error in concentration) with the experimental results under industrially relevant operating conditions. Modeling results illustrated that the radial velocity distribution over the monolith channels has an important effect on the shape of the breakthrough curve as well as the 5% breakthrough time. Both experimental results and modeling predictions showed that the long tails of the adsorption breakthroughs were the result of the non-uniform flow distribution, which resulted in delayed saturation of the outer honeycomb channels.