3D simulations of a microchannel reactor with diffusion inside the catalyst layer for 1-butanol dehydration reaction in gas phase

Abstract

3D and a 2D-axisymmetric models in COMSOL Multiphysics® environment were developed to address modeling strategies to optimize the performance of wall-coated microstructured reactors operated to study gas-phase reactions under isothermal conditions. The kinetics for 1-butanol dehydration reaction was derived in our previously published research. Typically ideal models are used for modelling bulk flow in the free channel with diffusion–reaction at the surface of the layer. However in order to solve the system non-idealities, we used non-ideal models to simulate the flow field inside the free channel and diffusion–reaction in the catalyst coating. The obtained results from the 3D and 2D-axisymmetric models developed in COMSOL Multiphysics® were compared mainly with 2D-PFR-type model developed in MATLAB®. The one-way coupling between the fluid flow and transport of the components revealed that flow field non-idealities effect the performance predictions for the system. The performance and efficiency of the washcoat catalyst in microstructured reactors can be improved by controlling the thickness of the catalyst layer. As a conclusion, to optimize the performance of microstructured reactors the effect of reactor flow field must also be considered besides, the other key operational parameters such as global residence time, reaction conditions and catalyst layer thickness.