Optimizing operational strategies in a non-isothermal bench-scale fixed-bed reactor for CO2 hydrogenation to CH4 combining experimental and modeling and simulation approaches

Abstract

The CO₂ methanation reaction is a promising solution for renewable energy storage. However, the process is challenged by thermal management due to its exothermic nature, leading to hot spots that complicate reactor operation and scale-up. This study combines experimental and simulation approaches to optimize the operation of a bench-scale fixed-bed reactor. Experimental results show that reactor wall temperature, flow rate, and nitrogen dilution significantly affect temperature profiles and CO₂ conversion. As a refrigeration strategy, it has been studied the use of pressurized air jackets to improve heat dissipation and stabilize the operation. A dynamic 1D heterogeneous model validated these findings and enabled simulation-based optimization. Non-uniform particle size distributions, metal loading, and SiC dilution strategies effectively mitigated hot spots without compromising CH₄ yield. These results offer critical insights into reactor design, ensuring stable operation and high efficiency.