The CPA Equation of State and an Activity Coefficient Model for Accurate Molar Enthalpy Calculations of Mixtures with Carbon Dioxide and Water/Brine

doi:10.2172/1194030

GSTDTAP > 地球科学

DOI	10.2172/1194030
报告编号	LLNL--TR-672077
来源ID	OSTI ID: 1194030
	The CPA Equation of State and an Activity Coefficient Model for Accurate Molar Enthalpy Calculations of Mixtures with Carbon Dioxide and Water/Brine
	Myint, P. C.; Hao, Y.; Firoozabadi, A.
	2015-03-27
出版年	2015
页数	43
语种	英语
国家	美国
领域	地球科学
英文摘要	Thermodynamic property calculations of mixtures containing carbon dioxide (CO₂) and water, including brines, are essential in theoretical models of many natural and industrial processes. The properties of greatest practical interest are density, solubility, and enthalpy. Many models for density and solubility calculations have been presented in the literature, but there exists only one study, by Spycher and Pruess, that has compared theoretical molar enthalpy predictions with experimental data [1]. In this report, we recommend two different models for enthalpy calculations: the CPA equation of state by Li and Firoozabadi [2], and the CO₂ activity coefficient model by Duan and Sun [3]. We show that the CPA equation of state, which has been demonstrated to provide good agreement with density and solubility data, also accurately calculates molar enthalpies of pure CO₂, pure water, and both CO₂-rich and aqueous (H₂O-rich) mixtures of the two species. It is applicable to a wider range of conditions than the Spycher and Pruess model. In aqueous sodium chloride (NaCl) mixtures, we show that Duan and Sunâs model yields accurate results for the partial molar enthalpy of CO₂. It can be combined with another model for the brine enthalpy to calculate the molar enthalpy of H₂O-CO₂-NaCl mixtures. We conclude by explaining how the CPA equation of state may be modified to further improve agreement with experiments. This generalized CPA is the basis of our future work on this topic.
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来源平台	US Department of Energy (DOE)
引用统计
文献类型	科技报告
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/7062
专题	地球科学
推荐引用方式 GB/T 7714	Myint, P. C.,Hao, Y.,Firoozabadi, A.. The CPA Equation of State and an Activity Coefficient Model for Accurate Molar Enthalpy Calculations of Mixtures with Carbon Dioxide and Water/Brine,2015.