An improved model for calculating CO2 solubility in aqueous NaCl solutions and the application to CO2–H2O–NaCl fluid inclusions
An improved model for calculating CO2 solubility in aqueous NaCl solutions and the application to CO2–H2O–NaCl fluid inclusions
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DOI：
10.1016/j.chemgeo.2013.03.010
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发表时间：
2013-06
期刊：
影响因子：
3.9
通讯作者：
Shide Mao;Dehui Zhang;Yongquan Li;Ningqiang Liu
中科院分区：
文献类型：
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作者：
Shide Mao;Dehui Zhang;Yongquan Li;Ningqiang Liu
为了确定二氧化碳-水-氯化钠流体包裹体的组成、均一压力和等温线，建立了一个改进的活度-逸度模型来计算二氧化碳在氯化钠水溶液中的溶解度。该模型可以预测273.15K-723.15K、1bar-1500bar和0-4.5molkg−-1的CO2在氯化钠水溶液中的溶解度，在实验不确定度范围内或接近实验不确定度。与大量可靠的实验数据相比，CO2在氯化钠水溶液中的溶解度的平均绝对偏差为4.62%。在近临界区，计算的CO2溶解度偏差增加到10%以上。基于包裹体在加热和冷却过程中体积不变的假设，采用CO2溶解度模型和改进的CO2-H2O-NaCl混合流体体积模型，采用迭代方法计算了CO2-H2O-NaC l流体包裹体的CO2含量、均一压力、摩尔体积和体积分数。CO2在氯化钠水溶液中的溶解度计算程序代码可从化学地质或通讯作者(maoshide@163.com)获得。
To determine compositions, homogenization pressures and isopleths of CO2–H2O–NaCl fluid inclusions, an improved activity–fugacity model is developed to calculate CO2solubility in aqueous NaCl solutions. The model can predict the CO2solubility in aqueous NaCl solutions from 273.15K to 723.15K, from 1bar to 1500bar and from 0 to 4.5molkg−1of NaCl, within or close to experimental uncertainties. Compared to a large number of reliable experimental solubility data available, the average absolute deviation is 4.62% for the CO2solubility in aqueous NaCl solutions. In the near-critical region, the calculated CO2solubility deviations increase to over 10%. The CO2solubility model, together with the updated volumetric model of CO2–H2O–NaCl fluid mixtures, is applied to calculate the CO2contents, homogenization pressures, molar volumes and volume fractions of the CO2–H2O–NaCl fluid inclusions by an iterative method based on the assumption that the volume of an inclusion keeps constant during heating and cooling. Calculation program code of the CO2solubility in aqueous NaCl solutions can be obtained from Chemical Geology or the correspondence author (maoshide@163.com).