Optimal Design of Microreactors using a Hierarchical Modeling Approach

Optimal Design of Microreactors using a Hierarchical Modeling Approach

Abstract

A hierarchical approach to modeling the interaction between transport, diffusion, and catalytic reactions is undertaken to understand the operation and stability of microreactors. A hierarchy of models describing the chemistry at the catalyst surface - full microkinetic models, reduced order models, and simple power-law models - are used and their performance is assessed. A simplified pseudo-two-dimensional reactor model is developed and benchmarked against computationally intensive computational fluid dynamics (CFD) model. This hierarchical modeling scheme is applied to homogeneous and catalytic combustion, and to integrated microreactors for hydrogen generation. For microreactors with critical dimension of 1000 microns or lower, the 1D model with reduced order rate expression was shown to have excellent agreement with the more complex CFD model, but at a significantly lower computational cost. The resulting model is validated with experimental data on cataolytic microburner.