Technological evaluation of mineral sequestration of carbon dioxide by carbonation

Increase in CO₂ emissions has led to development of various mitigation technologies for avoiding CO₂ building up in the atmosphere. One of CO₂ sequestration technologies is mineral sequestration, a way of permanent storage of CO₂ in solid minerals. This technology attracts the attention of many investigators to study and develop various carbonation approaches.; The chemistry and thermodynamic studies show that mineral carbonation reactions with silicate minerals are spontaneous and exothermic. A variety of measures are needed to enhance the carbonation kinetics. The main minerals used for mineral sequestration are serpentine and olivine, which exist in vast quantities worldwide. Implementation of mineral sequestration needs to address related energy consumption and environmental consequences.; The mineral sequestration approaches include chloride based mineral sequestration, direct dry carbonation, direct carbonation in aqueous solutions, integrated carbonation, in-situ carbonation in geologic formations, biomineralization with fly ash, and zero emission coal alliance (ZECA) process. Among all the mineral sequestration approaches, direct carbonation in aqueous solutions is the most promising method. Under optimal conditions, 78% stoichiometric conversion of silicate to carbonate was achieved in 30 minutes.