CFD simulation of the Sabatier process in a shell-and-tube reactor under local thermal non-equilibrium conditions: Parameter sensitivity and reaction mechanism analysis

Abstract

The Sabatier process is a competitive technology applied for carbon capture and utilization. This process increases the risk of carbon deposition and catalyst thermal degradation because of its exothermic property. In this study, a CFD model verified through existing experimental data was established to systematically investigate the Sabatier process in a shell-and-tube reactor. The effects arising from several operating parameters (e.g., gas flow rate, feed gas composition, the thermal conductivity of catalyst pellet, the inlet temperature of cooling phase, as well as phase change refrigeration) on temperature profile and reaction performance were studied. Moreover, a mechanism of three reactions was investigated, including CO 2 methanation, CO methanation, as well as RWGS reaction. Furthermore, the competition between CO 2 methanation and RWGS reaction was explored. According to the further sensitivity analysis, increasing the thermal conductivity of the catalyst particles would be effective to inhibit hot spots, while keeping the carbon conversion rate unchanged. • A CFD model of the Sabatier process under local thermal non-equilibrium conditions. • The conjugate heat transfer among gas, catalyst bed, reactor, and cooling phase. • A mechanism of three reactions on the Sabatier process was explored. • Parameter sensitivity of operating parameters for the Sabatier process was analyzed.