Modeling and Simulation of Reacting Systems: A COMSOL Multiphysics Approach for Chemistry Education

This article presents a comprehensive overview of modeling and simulation strategies for chemically reacting systems using the COMSOL Multiphysics®software, with a focus on applications in chemical engineering and chemistry education. Beginning with the historical development of the Chemical Reaction Engineering Module and its integration with the CFD Module, we describe how these tools implement the equations of change, reaction kinetics, and thermodynamics for both idealized and spatially resolved systems. The modeling strategy emphasizes a progression from space-independent models to fully coupled multiphysics simulations, illustrated with examples including selective catalytic reduction, heterogeneous catalysis with dual-porosity media, and reacting flow systems in pharmaceutical processes. The use of extra dimensions for intraparticle transport, as well as integration of fluid flow, heat transfer, and chemical reactions, demonstrates the software's capability to address multiscale and multiphysics problems. Finally, we discuss emerging approaches using surrogate models and deep neural networks to accelerate simulations and enable real-time interactivity in the classroom. These methods broaden the pedagogical scope, enabling students - from undergraduate students to graduate researchers - to explore complex reacting systems with greater accessibility, speed, and engagement.