Potential carbon dioxide sequestration using biomass combustion ash

Biomass combustion generates solid residues (ash) and greenhouse gaseous emissions. Based on the chemical and mineralogical characteristics, biomass fly ash is an alkaline waste material that could potentially be employed as a substrate for mineral carbonation. In this paper, mineralogical sequestration of carbon dioxide by means of biomass fly ash carbonation was investigated by conducting experimental accelerated carbonation tests. Fly ash resulted to be a promising substrate for carbon dioxide sequestration, and the sequestration potential in relation to direct and indirect emission factors was assessed. Leaching behaviour of treated ash was also studied, and an environmental issue concerning the increased leachability of treated selenium and molybdenum comparing to the untreated residue was raised.