Fixation of CO2 by carbonating calcium derived from blast furnace slag

CO2 Capture by Accelerated Carbonation of Alkaline Wastes: A Review on Its Principles and Applications

“…Therefore, CO 2 capture by carbonating the steelmaking slags could be an interesting option for reducing CO 2 emissions from the steel plant. In recent years, accelerated carbonation of steelmaking slags has been progressively tested to assess the CO 2 capture potential of this material (e.g., Huijgen et al, 2005c;Bonenfant et al, 2008;Teir, 2008;Eloneva et al, 2008a;Kodama et al, 2008;Costa, 2009;Wang and Yan, 2010;Chang et al, 2011a, b;De Windt et al, 2011). Fig.…”

“…In indirect carbonation processes, e.g., pH-swing methods (Park and Fan, 2004;Eloneva et al, 2008a;Kodama et al, 2008;Doucet, 2010;Wang and Maroto-Valer, 2011), reactive alkaline earth metals are first extracted from the solid matrix and then carbonated. Fig.…”

“…CaO), residues from APC (Ca content up to 35%) and bauxite (4.8% Ca), cement kiln dust (~34-50% wt. CaO), oil-shale waste (CaO content up to 50%), and fly ash (53% CaO) from municipal solid waste incinerators (Huijgen et al, 2005b;Bonenfant et al, 2008;Eloneva et al, 2008a;Baciocchi et al, 2009c; 2011a). Industrial alkaline solid wastes such as sources of calcium or magnesium oxide are ideal CO 2 sequestration materials due to their availability and low cost.…”

“…The basic goal of accelerated carbonation is to mimic the natural weathering processes in which CO 2 reacts with metal oxide bearing materials to form stable and insoluble carbonates, with calcium-or magnesium-oxide being the most favourable metal oxide in reacting with CO 2 . Besides that, carbonation is an exothermal reaction, so energy consumption and costs may be reduced by its inherent properties (Lackner, 2003;Eloneva et al, 2008a;Baciocchi et al, 2009a). In all cases, carbonation must provide base ions, such as monovalent sodium and potassium, or divalent calcium and magnesium ions to neutralize the carbonic acid (Costa et al, 2007;Gerdemann et al, 2007).…”

“…The potential advantages of accelerated carbonation of applied industrial alkaline solid wastes include: (a) carbonation is an exothermal reaction and hence energy consumption and costs may be reduced by its inherent properties; (b) carbonation products such as calcium or magnesium carbonates are thermodynamically stable under ambient conditions, that is, in the absence of acidification. ; (c) it offers great sequestration capacity due to the high availability of deposits; (d) it does not require transport at sites within steel-works and is therefore cost-effective; (e) products may be beneficially reused in a variety of application, such as construction materials; (f) carbonation eliminates environmental impacts due to decreased leaching of heavy metal trace elements such as Pb, Ni, and Cd from residues and stabilizing of the waste leading to an improvement of environmental quality; and (g) it could neutralise the pH of the solution as carbonate precipitations are formed if alkaline wastewater is used as the liquid agents (Lackner, 2003;Fernandez-Bertos et al, 2004a;Huijgen et al, 2005b, c;Costa et al, 2007;Eloneva et al, 2008a;Bonenfant et al, 2009;Huntzinger et al, 2009a;Gunning et al, 2010;Lim et al, 2010). This paper focuses on accelerated carbonation of industrial alkaline wastes, e.g., steelmaking slags and metalworking wastewater.…”