(183b) A Computational Investigation of the Effect of Packing Structural Features on the Performance of Carbon Capture for Solvent-Based Post-Combustion Applications.

A major pillar for the decarbonization of point sources emitting CO₂ and other impurities is carbon capture, utilization and sequestration (CCUS). CCUS is also vital for the development of the much-needed negative emission technologies. In this work we focus on improving the efficiency of the capture rate of an absorber by designing a device offering in situ cooling. The effective heat management of absorption has been established experimentally as a key pathway for improving overall capture performance, making worthwhile the efforts to comprehend the effect of geometry on conjugate heat transfer coupled to mass and momentum transport.

In our previous work we have successfully incorporated detailed thermodynamics and reaction kinetics into hydrodynamics simulations of the two-phase flow system with an exothermic absorption reaction and generated a few showcases to demonstrate the framework. As a next step we wish now to delineate the effect of the geometry and all related features used to describe it on the metrics that determine the absorber’s performance and to promote heat transfer. To that end we have generated python codes to produce a series of fully controlled structures in 2D and 3D that are swiftly imported into our CFD models. For each constructed geometry, we perform CFD simulations by modeling the two immiscible phases as multi-component reacting mixture of MEA–H₂O–CO₂ solution and flue gas. We numerically solve the transport equations for participating species separately within each phase by explicitly tracking the interface using a mass-conserving volume of fluid method. We characterize the effect of geometrical parameters on the interfacial and wetted areas, liquid holdup, pressure-drop, overall mass and heat transfer coefficients and driving forcers, CO₂ absorption rate, and corresponding temperature changes in the solvent for different operating conditions. Post-processing of these data will help guide the development of optimal packing configurations. We use a variety of 2D and 3D Multiphysics simulations to evaluate the accuracy and performance of our approach and to get insights about scaling the technology to higher scales.