Modeling kinetics of CO2 (carbon dioxide) mineral sequestration in heterogeneous aqueous suspensions systems of cement dust

The necessity to reduce CO2 emission in the environment has encouraged people to search for solutions for its safe capture and storage. Known methods for carbon dioxide mineral sequestration are based primarily on the use of its binding reaction with metal oxides, mainly alkaline earth metals. Increasingly important, due to the availability and price, are processes based on the suspension of various wastes such as fly ash, cement dust or furnace slag. Due to the complexity of the mineral sequestration of CO2 in water-waste suspensions, an important issue is to determine the reaction mechanisms. This applies mainly to the initial period of the transformation phase of mineral wastes, and consequently with the occurrence of a number of transition states of ionic equilibria. The mechanisms and reaction rates in the various stages of the process of CO2 mineral sequestration in heterogeneous systems containing selected wastes are defined herein. This paper presents a method of modeling kinetics of this type of process, developed on the basis of the results of the absorption of CO2 thanks to the aqueous suspension of fly ash and cement dust. This allowed for the transfer of obtained experimental results into the mathematical formula, using the invariant function method, used to describe the processes.