CO2 Sequestration via Olivine Dissolution and Carbonation by Using (HPEC) and (HPIC)

CO2 storage by mineral carbonation is one option to limit the rise of anthropogenic CO2 concentration in the atmosphere and to minimize climate change, which is the most significant environmental challenge in the world today. Olivine is one of the most investigated mineral resources for carbonization. In this study, independent variables were investigated, including effects of temperature, pressure, additives and particle size. The effects of these parameters are compared to the literature by using a High Pressure Environmental Chamber (HPEC) and a High Pressure Incubation Chamber (HPIC): i) This study was consistent with previous studies showing that smaller particles produce more rapid reactions. ii) Additives 2.5 M NaHCO3 and 1M NaCl + 0.64 M NaHCO3 accelerated the reaction. The 2.5 M NaHCO3 additive increased the reaction rate of dissolution of olivine more than other additives, both early in the reaction and for the overall reaction. Without additives, olivine dissolution rate is relatively slow and leads to small amounts of precipitated magnesite. iii) Temperature showed an increase in reaction rate and was consistent with the study by Mckelvy et al (2006). iv) Pressure did not show any obvious effect. This result does not agree with the study of Mckelvy et al (2006). This result shows that increasing the pressure of CO2 only produces small amounts of CO3 2- for olivine carbonization. Nesquehonite was precipitated from the reaction of CO2 with olivine without any pre-treatment in the HPEC. This approach for sequestration is relatively safe and simple, and provides a potential method of CO2 sequestration by trapping CO2 and forming a stable mineral at ambient conditions. Due to the slow reaction rate, the HPEC is not optimized to study olivine carbonation. With the improvement of the design of the valve on HPIC, this vessel is more suitable to study the olivine reaction.