The usage of rankinite for carbon capture and storage and carbonation kinetics

ABSTRACTLow-calcium rankinite C3S2 (3CaO•2SiO2) cement is an a dvanced low-calcium and saving energy cement which hardens by carbonation. The progress of rankinite carbonation and the mechanical strength of C3S2 carbonized block were studied. The effects of time, CO2 pressure, temperature, and relative humidity (RH) during carbonation-curing on C3S2 powder were also investigated. We especially focus on the establishment of kinetic equation of carbonation-curing of C3S2 powder. The results show that the main product of C3S2 carbonization is CaCO3. As a result, 1 kg of C3S2 could capture 0.15 kg CO2 after 12 h of carbonation-curing, and the compressive strength was 10.2 and 21.3 MPa after carbonation for 3 and 12 h, respectively. The developed kinetic model was able to predict the relationship of carbonation degree and time, temperature, CO2 pressure, and RH under the tested carbonation conditions.