Computational fluid dynamics (CFD) simulation of CO2 methanation in a shell-and-tube reactor with boiling water cooling

CO₂ methanation plays a crucial role in carbon cycling and CCU technologies. However, this reaction is highly exothermic, thus requiring significant thermal management. In this investigation, the DEM method was employed to construct a realistic packed bed structure, allowing for the quantification of the radial particle distribution and radial activity ratio. The influence of internal diffusion on the methanation process was simulated using a single-particle model. Building on this, a single shell-and-tube reactor model with a three-dimensional geometric structure was developed. Boiling water was used as the coolant to simulate the reaction and heat transfer processes within the CO₂ methanation reactor. The effects of inert particles, feed flow rate, H₂/CO₂ feed ratio, and operating pressure on the reaction and heat transfer processes were investigated. This study provides important theoretical and technical support for the design optimization and industrial application of CO₂ methanation reactors.