An Overview: Reaction Mechanisms and Modelling of CO2 Utilization via Mineralization

Accelerated carbonation using alkaline solid wastes has been considered an effective approach to mineralizing flue gas CO2 from industries or power plants. Despite its recent progress, mechanistic understanding and modelling at interface levels are still needed to control the reactivity and equilibrium of the reaction system. This review focuses on several phenomenological models for accelerated carbonation that look at the solid-fluid interface. We first illustrate the principles of kinetic and mass transfer driven reactions for CO2-mineral-water systems. Then, we provide an overview into the reaction mechanisms and modelling for CO2 mineralization including leaching-precipitation model, shrinking core model and surface coverage model. Advanced models considering multiple mechanisms, such as two-layer diffusion model, are also discussed. Finally, the perspectives and prospects are provided to shine a light on future directions, including incorporation of structural and physical properties in phenomenological models, identification of dynamic speciation by in-situ high-resolution equipment, and integration of heat transfer in reaction modelling for system optimization.