Diffusion of CO2 in Magnesite under High Pressure and High Temperature from Molecular Dynamics Simulations
Lei Liu,
Longxing Yang,
Chunqiang Zhuang,
Guangshu Yang,
Li Yi,
Hong Liu,
Fengxia Sun,
Xiaoyu Gu,
Hanyu Wang
Affiliations
Lei Liu
United Laboratory of High-Pressure Physics and Earthquake Science, Institute of Earthquake Forecasting, Chinese Earthquake Administration, Beijing 100036, China
Longxing Yang
State Key Laboratory of Geological Processes and Mineral Resources, and School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
Chunqiang Zhuang
Institute of Microstructure and Property of Advanced Materials, Beijing Key Lab of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124, China
Guangshu Yang
Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming, 650093 Yunnan, China
Li Yi
United Laboratory of High-Pressure Physics and Earthquake Science, Institute of Earthquake Forecasting, Chinese Earthquake Administration, Beijing 100036, China
Hong Liu
United Laboratory of High-Pressure Physics and Earthquake Science, Institute of Earthquake Forecasting, Chinese Earthquake Administration, Beijing 100036, China
Fengxia Sun
United Laboratory of High-Pressure Physics and Earthquake Science, Institute of Earthquake Forecasting, Chinese Earthquake Administration, Beijing 100036, China
Xiaoyu Gu
United Laboratory of High-Pressure Physics and Earthquake Science, Institute of Earthquake Forecasting, Chinese Earthquake Administration, Beijing 100036, China
Hanyu Wang
United Laboratory of High-Pressure Physics and Earthquake Science, Institute of Earthquake Forecasting, Chinese Earthquake Administration, Beijing 100036, China
CO2 transports in the Earth’s interior play a crucial role in understanding the deep carbon cycle and the global climate changes. Currently, CO2 transports inside of the Earth under extreme condition of pressure and temperature have not been understood well. In this study, the molecular dynamics (MD) calculations were performed to study CO2 transports under different CO2 pressures in slit-like magnesite pores with different pore sizes at 350~2500 K and 3~50 GPa are presented. Diffusion of CO2 in magnesite was improved as the temperature increases but showed the different features as a function of pressure. The diffusion coefficients of CO2 in magnesite were found in the range of 9×10−12 m2 s−1~28000×10−12 m2 s−1. Magnesite with the pore size of 20~25 Å corresponds to the highest transports. Anisotropic diffusion of CO2 in magnesite may help to understand the inhomogeneous distribution of carbon in the upper mantle. The time of CO2 diffusion from the mantle to Earth surface was estimated to be around several tens of Ma and has an important effect on deep carbon cycle. The simulation of CO2 transports based on the Earth condition provides new insights to revealing the deep carbon cycle in the Earth’s interiors.
