Rapid Carbonation for Calcite from a Solid-Liquid-Gas System with an Imidazolium-Based Ionic Liquid

Aqueous carbonation of Ca(OH)(2) is a complex process that produces calcite with scalenohedral calcite phases and characterized by inadequate carbonate species for effective carbonation due to the poor dissolution of CO(2) in water. Consequently, we report a solid-liquid-gas carbonation system with an ionic liquid (IL), 1-butyl-3-methylimidazolium bromide, in view of enhancing the reaction of CO(2) with Ca(OH)(2). The use of the IL increased the solubility of CO(2) in the aqueous environment and enhanced the transport of the reactive species (Ca(2+) and CO(3)(2−)) and products. The presence of the IL also avoided the formation of the CaCO(3) protective and passivation layer and ensured high carbonation yields, as well as the production of stoichiometric rhombohedral calcite phases in a short time.