Experimental and CFD analysis of heat generation during fly ash carbonation from FBC boiler

Tomasz Janoszek, Central Mining Institution – National Research Institute, Department of Extraction Technologies, Rockburst and Risk Assessment, Poland

Author ORCID Identifier

Abstract

The transition toward a closed-loop economy and improved energy efficiency in the industrial sector has highlighted the importance of waste heat recovery and carbon dioxide (CO₂) sequestration. This study investigates the carbonation of fly ash derived from fluidized bed boilers as a method for stabilizing reactive calcium oxide (CaO) while recovering the exothermic heat released during the process. Fly ash carbonation involves reactions between free CaO, CO₂, and water, forming stable calcium carbonate (CaCO₃) and generating significant thermal energy. Laboratory experiments were conducted in an adiabatic rotary reactor equipped with seven thermocouples to monitor the temperature profile of the carbonating ash. The reactor was exposed to a controlled stream of CO₂ to initiate and sustain the carbonation reactions. Experimental results were compared with temperature distributions obtained from computational fluid dynamics (CFD) simulations. The study confirms that fly ash carbonation not only reduces the content of free CaO, enhancing its suitability for reuse in construction applications, but also provides a viable opportunity for industrial waste heat recovery. These findings support the integration of carbonation processes into energy and material recovery systems, contributing to reduced greenhouse gas emissions and alignment with EU circular economy goals.

Recommended Citation

Janoszek, Tomasz (2026) "Experimental and CFD analysis of heat generation during fly ash carbonation from FBC boiler," Journal of Sustainable Mining: Vol. 25 : Iss. 4 , Article 1.
Available at: https://doi.org/10.46873/2300-3960.1516