Pore-Scale Study of Diffusion and Adsorption Mechanisms during Capture of Atmospheric Carbon Dioxide

Abstract

The surge in the global average temperatures has necessitated a decrease in the level of the released carbon dioxide (CO2) from different anthropogenic sources. In addition to curtailing the various emissions, there is a growing demand to remove the CO2 already existing in the atmosphere. As such, there is an impetus for synergistic experimental and modeling studies as it can propel the endeavor toward the development of durable and less energy-intensive CO2 capture systems. In this work, a physics-based numerical model employing the Lattice-Boltzmann Method (LBM) is formulated to simulate the coupled mass transfer and adsorption phenomena occurring during CO2 capture. A modeling workflow integrated with experiments will be presented which aids in the determination of the pertinent reaction order and adsorption rate constant based on a mixed-order kinetic model. The influence of Damköhler number, porosity, and microporosity content of the carbon fiber domain on key metrics such as the adsorption efficiencies and time constants will be further delineated.