CO 2 capture technology is a crucial method to achieve global carbon emission reduction, and the benefits of the physical adsorption method in the post-combustion CO 2 capture technology are low energy usage and running costs. Nitrogendoped porous carbon is selected as a solid adsorbent due to its high specific surface area and excellent adsorption selectivity. This study uses nitrogen-doped porous carbon prepared in experiment to determine its main properties, and the adsorption equilibrium isotherm is fitted. The adsorption bed model is established using ANSYS Fluent to simulate the heat and mass transfer of the adsorption process and fluid flow and is verified by the published experimental data. Temperature swing adsorption (TSA) is divided into three stages: adsorption, desorption, and cooling. The effects of different inlet velocities and porosities on adsorption and desorption performance are studied. The results reveal that the mesh verification and experimental verification are in good agreement with the results so that the numerical model can be used for species transport processes of various sizes, geometric shapes, and other mixed gases. It is essential to mention that this adsorption cycle process can recover excellent purity and decent recovery and productivity of product gases, which is of great significance for the practical application and industrialization of carbon capture technology.