Simulation design and optimization of reactors for carbon dioxide mineralization

Abstract

To achieve a synergistic solution for both sustainable waste management and permanent CO₂ sequestration, CO₂ mineralization via fly ash particles is an option. Based on computational fluid dynamics, two specialized reactors for fly ash mineralization were designed. The reactor designs were strategically tailored to optimize the interactions between fly ash particles and flue gas within the reactor chamber while concurrently facilitating efficient post-reaction-phase separation. The impinging-type inlet configuration dramatically enhanced the interfacial interaction between the fly ash particles and the gaseous mixture, predominantly composed of CO₂ and steam. This design modality lengthens the particle residency and reaction times, substantially augmenting the mineralization efficiency. A rigorous investigation of three operational parameters, that is, flue gas velocity, carrier gas velocity, and particle velocity, revealed their influential roles in gas-particle contact kinetics. Through a computational investigation, it can be ascertained that the optimal velocity regime for the flue gas was between 20 and 25 m⋅s⁻¹. Concurrently, the carrier gas velocity should be confined to the range of 9–15 m⋅s⁻¹. Operating within these finely tuned parameters engenders a marked enhancement in reactor performance, thereby providing a robust theoretical basis for operational efficacy. Overall, a judicious reactor design was integrated with data-driven parameter optimization.