Multicomponent and multi-dimensional modeling and simulation of adsorption-based carbon dioxide separation

Abstract

Abstract A two-dimensional transient numerical study of the adsorption of CO2/N2 and CO2/H2 mixtures on activated carbon and MOF-177 in a fixed bed is presented. Because most of the commercial CFD codes are not capable of simulating adsorption processes in a straightforward fashion, we developed an additional code to solve for the different species transport including adsorption and diffusion and used Fluent to simulate the adsorption process, fluid flow, heat and, mass transfer. We simulated the adsorption process at high temperature-low pressure and low temperature-high pressure conditions as well as the pressure swing adsorption. For adsorption of CO2/N2 and CO2/H2 mixtures, Toth and Viral models are used calculate equilibrium isotherms. The breakthrough curves obtained from the simulations compare well with the experimental data. Moreover, the effects of aspect ratio and geometric shapes were studied. The results show that varying the bed aspect ratio from 7.77 to 2 has an insignificant effect on the adsorption capacity and performance.