Abstract
Carbon dioxide (CO2) methanation is a promising pathway for CO2 utilization and renewable energy storage. However, the highly exothermic nature of the reaction may lead to significant temperature rise and hot spot formation in catalytic reactors, posing challenges for reactor safety and thermal management during scale-up. In this work, a computational fluid dynamics (CFD) model was developed to investigate the CO2 methanation process over a commercially available 10%Ru/γ-Al2O3 catalyst. The model was validated using experimental kinetic data and applied to analyze temperature distribution, species concentration, and reactor performance under different operating conditions and reactor configurations. Particular attention was given to the formation of hot spots in packed bed reactors and the potential of coated reactor designs for improved thermal control. The simulation results indicate that significant temperature gradients and hot spots can occur in packed reactors due to the strong exothermicity of the reaction. In contrast, coated reactor configurations enhance heat dissipation and effectively suppress temperature rise, reducing the maximum temperature increase by up to approximately 25 °C under comparable conditions. The results demonstrate that coated reactors provide improved thermal management and can mitigate hot spot formation while maintaining comparable methane production performance. This study provides insights into reactor design strategies for safer and more efficient CO2 methanation processes.
•A CFD model was developed to investigate hot spot formation and thermal behavior in CO2 methanation reactors under varying operating conditions.•The influence of reactor configuration on temperature distribution was evaluated, showing that coated reactors effectively suppress temperature rise compared to packed-bed systems.•The results provide insights into thermal risk mitigation and support the design of inherently safer reactors for highly exothermic methanation processes.