CO₂ sequestration by direct mineral carbonation of serpentine under medium and low pressure

Serpentine was used as the mineral material for CO₂ sequestration by direct mineral carbonation under medium and low pressure. A series number of experiments were carried out to investigate the factors that influence the conversion of carbonation reaction, such as temperature, pressure, particle size, solution composition and pretreatment. The results show that serpentine can be used to sequestrate CO₂ in simulated flue gas by aqueous direct mineral carbonation under medium and low pressure. Carbonation conversion increases with increasing temperature and pressure. Decrease in mineral particle sizes and use of heat treatment before carbonation can effectively improve the conversion. The addition of NaHCO₃, which has a buffering effect that kept the solution pH in a certain range, can also improve the carbonation conversion. The highest carbonation conversion of 47.7% and 36.3% was obtained in 60 min under 4 MPa and 150℃ for pure CO₂ gas and simulated flue gas, respectively.