Dynamic Modeling of an Evaporation Cooled Micro-Structured Reactor - The Case of CO2 Methanation

This is the Zenodo repository of the publication: Dynamic Modeling of an Evaporation Cooled Micro-Structured Reactor - The Case of CO2 MethanationThe repository contains all figure data contained in the publication.AbstractConverting renewable electricity and captured CO2 into synthetic natural gas is a key element of the energy transition. Compact microstructured reactors with evaporative cooling are promising for this Power-to-Gas pathway, but their safe operation requires robust thermal stability. This work develops an open-source dynamic model to investigate the coupled effects of heat release from CO2 methanation, heat conduction through the reactor wall, and two-phase flow boiling in a plate-type microreactor. A parametric study reveals an exceptionally narrow admissible operating window of only ±2 °C in coolant temperature, bounded by reaction extinction and critical temperature excursion. Two coolant distribution strategies are compared. The spatially redistributed configuration simultaneously achieves conversions high enough for injection into the german natural gas grid and produces superheated steam suitable for electrolyzer integration. Dynamic cooling failure simulations reveal a pronounced asymmetry between upstream and downstream disturbances:downstream failures are benign, whereas upstream failures induce irreversible steady-state shifts through a hysteresis mechanism driven by positive feedback between heat release and hotspot migration. Critically, even sub-threshold failures that do not exceed the 500 °C catalyst limit produce permanent hotspot migration, and a critical failure duration of approximately 5 s is identified beyond which recovery requires controlled shutdown. These findings establish that temperature exceedance alone is an insufficient health indicator and provide a quantitative basis for model-based monitoring and control strategies for this reactor class.