JI Jiayuan, ZHAO Lingling, LI Siyu. Temperature and pressure effect on interfacial tensions of CO2-brine system[J]. CIESC Journal, 2017, (7): 2880-2885. DOI: 10.11949/j.issn.0438-1157.20161837.
JI Jiayuan, ZHAO Lingling, LI Siyu. Temperature and pressure effect on interfacial tensions of CO2-brine system[J]. CIESC Journal, 2017, (7): 2880-2885. DOI: 10.11949/j.issn.0438-1157.20161837.DOI:
Temperature and pressure are important effect factors of the efficiency and quantity of CO2 storage in the deep saline aquifers. Molecular dynamics (MD) simulation is applied to investigate the CO2-NaCl systems in 343-373 K and 6-35 MPa
the interfacial tensions (IFT) which are obtained from the simulations are consistent with experimental results and the pressure balance point pplateau are observed as well in this paper. Meanwhile
the interfacial tension variations with the temperature and pressure are analyzed and the reasons of pplateau from the molecular viewpoint are explained. The results show that the pressure rise and temperature decline will increase CO2 density and decrease IFT before pplateau
but after pplateau the IFT will be stable and less affected by temperature. In addition
the changes of CO2 surface excess and the hydrate quantities with temperature and pressure showed the opposite trend compared with IFT variations
the saturation phenomena of hydrates at the interface under high pressure may be the fundamental reason of pplateau.