Mineral carbonation by blowing incineration gas containing CO2 into the solution of fly ash and ammonia for ex situ carbon capture and storage

Abstract

The feasibility study on the accelerated mineral carbonation reveals that the addition of ammonia was important in the simplified two-step carbonation reaction, and that micro-bubbling and gas inflow speed were main factors for the reactions. The efficiency of CO2 uptake was 33.9% in the first step of carbonation process and increased to 58.6% in the second step. Calcium carbonate was obtained as product of Ca conversion up to 56.6% as a maximum conversion, through first and second carbonations. In the mineralogical analysis of ash, XRD pattern showed that, as carbonation proceed, the peaks of Ca(OH)2 and CaClOH disappeared, and intensity of CaCO3 peaks increased. Finally, scanning electron microscopy analysis also indicated that the fly ash particles became more crystalline with agglomeration by further carbonation using ammonia. The process suggested in this study could be applied in the eco-industrial parks.