中国化学工程学报(英文版)
中國化學工程學報(英文版)
중국화학공정학보(영문판)
CHINESE JOURNAL OF CHEMICAL ENGINEERING
2007年
3期
439-448
,共10页
吉远辉%吉晓燕%冯新%刘畅%吕玲红%陆小华
吉遠輝%吉曉燕%馮新%劉暢%呂玲紅%陸小華
길원휘%길효연%풍신%류창%려령홍%륙소화
CO2-H2O%CO2-H2O-NaCl%high temperature high pressure%phase equilibrium%density
To study the feasibility of CO2 geological sequestration, it is needed to understand the complicated multiple-phase equilibrium and the densities of aqueous solution with CO2 and multi-ions under wide geological conditions (273.15 473.15K, 0-60MPa), which are also essential for designing separation equipments in chemical or oil-related industries.For this purpose, studies on the relevant phase equilibria and densities are reviewed and analyzed and the method to improve or modify the existing model is suggested in order to obtain more reliable predictions in a wide temperature and pressure range.Besides, three different models (the electrolyte non random twoliquid (ELECNRTL), the electrolyte NRTL combining with Helgeson model (ENRTL-HG), Pitzer activity coefficient model combining with Helgeson model (PITZ-HG) are used to calculate the vapor-liquid phase equilibrium of CO2-H2O and CO2-H2O-NaCl systems.For CO2-H2O system, the calculation results agree with the experimental data very well at low and medium pressure (0-20MPa), but there are great discrepancies above 20MPa.For the water content at 473.15K, the calculated results agree with the experimental data quite well.For the CO2-H2O-NaCl system, the PITZ-HG model show better results than ELECNRTL and ENRTL-HG models at the NaCI concentration of 0.52mol·L-1.Bur for the NaCl concentration of 3.997mol·L-1,using the ELECNRTL and ENRTL-HG models gives better results than using the PITZ-HG model.It is shown that available experimental data and the thermodynamic calculations can satisfy the needs of the calculation of the sequestration capacity in the temperature and pressure range for disposal of CO2 in deep saline aquifers.More experimental data and more accurate thermodynamic calculations are needed in high temperature and pressure ranges (above 398.15K and 31.5MPa).