Influence of the geometry of recycled concrete aggregates on the carbonation process in an open system

Abstract

The “CO₂ capture using the recycled concrete aggregate” research program has been established to conceptualize a reactor as part of the national research program, Fastcarb. However, understanding the complex interaction between gas mixture (CO₂ + N₂) flow patterns, heat transfer phenomena and reaction in a porous media (carbonation) is very crucial for optimizing the performance of the reactor to maximize CO₂ capture. The study presents a comprehensive numerical investigation into the coupling of fluid flow and heat transfer phenomena within the reactor. The analysis uses the Computational Fluid Dynamics (CFD) technique to assess the thermal performance and fluid dynamics characteristics of the carbonation reactor while varying the shape and number of aggregates.  The results provide valuable insights into a deeper understanding of the gas flow and heat distribution in the reactor, which could help optimize the reactor performance. Additionally, the vorticity results around the sphere provide insight into the zone most likely to undergo carbonation, and the ‘dead zone’ where any CO2 gas would not interact with the aggregate.