Assessment of co2 capture via mineralization using coal fly ash

Abstract

Amid growing concerns about anthropologically induced climate change, the search for effective strategies to mitigate CO2 emission become paramount.CO2mineralization using fly ash can be a promising method to address this environmentally significantchallenge, especially in industries which emit substantial amount of CO2 and produce a huge amount of fly ash by product. The present study aimed at assessing the potential of coal fly ash as a source of carbon mineralization through ex-situ mineral carbonation. The study investigated the impact of solid to liquid ratio, reaction time, and temperature on the CO2 sequestration capacity and it compares the sequestration capacities between direct and indirect aqueous carbonation routes.The results indicate that sequestration capacity increases with reaction time, albeit with a decreasing carbonation rate over time. The optimum solid to liquid ratio was found to be 100 g/L, at which maximum sequestration occurred. Temperature has a marginal effect on sequestration capacity, with only a slight increase observed as temperature rises.In the direct aqueous route, maximum sequestration capacity reaches 12.25 g CO2/kg fly ash, while the pH swing method attains a sequestration capacity of 93.48 g CO2/kg fly ash.The presence and quantification of calcium carbonate in the carbonated product are verified through TGA, XRD, and SEM-EDS analysis.