Insight into interactions of olivine-scCO_2-water system at 140C and15 MPa during CO_2 mineral sequestration

作     者：Zijing Li Jilong Guo Zhao Dong Jiawei Chen 

作者机构：State Key Laboratory of Biogeology and Environmental GeologyChina University of GeosciencesBeijing 100083China School of Earth Sciences and ResourcesChina University of GeosciencesBeijing 100083China Department of Environmental HealthHavard T.H.Chan School of Public HealthBostonMA02115USA 

出 版 物：《Geoscience Frontiers》 (地学前缘（英文版）)

年 卷 期：2018年第9卷第6期

页      面：1945-1955页

核心收录：

学科分类：0709[理学-地质学] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 

基　　金：supported by National Natural Science Foundation of China(Grant Nos.41272061,41472232) National Innovation Experiment Program for university students(Grant No.201411415002) 

主　　题：Carbon storage CO2 mineral sequestration Olivine Magnesite Clay mineral 

摘      要：CO_2 mineral sequestration(in ultrabasic or basaltic rocks) has been considered as a promising long-term and stable approach to reduce CO_2 in the atmosphere and would counteract the effect of global ***, clays are widely found in ultrabasic reservoirs. In our study, clays were observed in natural olivine samples, which were used for laboratory experiments in a supercritical CO_2 system at 140C and15 MPa. Initial olivine samples were crushed into two sizes which were large grains of w850-1000 mm and powder particles of w75-150 mm, with the durations of 400 and 1000 h for the powder and grains,respectively. The results showed amorphous silica was newly formed and this passivating layer could mitigate the water-rock interaction to some extent, but it would not play a long-term prohibited effect on secondary mineral carbonate formation as it is a Fe(III) free silica coating. More interestingly, the secondary carbonates were observed to form near the surface sites where locates more clays. Our findings provide insights into the reaction mechanisms of olivine-scCO_2-water interaction process in natural ultrabasic rocks.