Electrolysis and heat pretreatment methods to promote CO2 sequestration by mineral carbonation

As a new mineral carbonation process for CO2 sequestration, electrolysis of NaCl solution and serpentine as the source of Mg2+ to adsorb CO2 in the simulating flue gas is introduced, which used the electrolyze NaCl solution to produce the HCl solution and NaOH solution. The HCl solution was used to dissolve Mg2+ from serpentine, and the NaOH solution was used to adsorb CO2 in simulation smoke, then these two solutions were mixed to form MgCO3 deposition at 358 K, which could be processed at relative low temperature and pressure. In order to further increase the solubility of Mg2+ from serpentine, the heat pretreatment of serpentine under nitrogen was investigated. The results indicated that the heat activation dramatically enhanced serpentine carbonation. XRD, TGA, FT-IR and ICP-AES analyses indicated that the best activation temperature was 650 °C, at which the crystalline features were changed from lizardite to amorphous followed the decomposition of hydroxyl groups. The dissolved capacity decreased with further increasing heat activation temperature, which might be related to the formation of a new crystalline feature. The XRD and TGA analyses showed that the solid product was mainly pure basic magnesium carbonate.