Feasibility of CO2 fixation via artificial rock weathering

Artificial rock weathering can potentially fix a large amount Of CO2 genera ted from industrial and other sources with a slight expense of mechanical e nergy. From technological, economic, and environmental perspectives, artifi cial rock weathering is a preferential method to dispose carbon dioxide. Ca rbonate and hydrogen carbonate ions are formed spontaneously when carbon di oxide is dissolved in an aqueous solution owing to the negative Gibbs free energy. The calcium silicate component of wollastonite reacts with carbonat e ions and becomes calcium carbonate and silicate. Such a reaction is econo mically feasible because this transformation does not require energy infusi on. The products are naturally stable and can be discharged safely without pollution. Experimental results indicated that, in an aqueous solution, 1 t on of wollastonite could fix nearly 140 kg of carbon dioxide. No carbonatio n was observed when using talc under our experimental conditions. The study indicate that the reaction rate of artificial rock weathering may still be too slow for commercialization. Therefore, successful commercialization hi nges on accelerating rock weathering reaction without increasing operationa l cost and increasing the efficiency of rock utilization.