Accurate prediction of gas solubility in liquid phase is of great significance for studying the stability and decomposition kinetics of gas hydrates.In this work,the Valderrama-Patel-Teja equation of state in conjunction with the Wong-Sandler mixing rule was adopted in correlating methane and carbon dioxide solubility data.In order to improve the predicting ability of gas solubility for saline solutions,the Debye-Hückel electrostatic contribution was taken into account.Moreover,the gas-solvent interactive parameters were evaluated via experimental data of gas solubility in water and the ion-gas interactive parameters were obtained by fitting low-pressure salting-out constants.The modified Patel-Teja equation of state was then integrated with the Chen-Guo hydrate model and was employed to predict gas solubility in water and saline solutions in the presence of hydrate.Comparing with experimental data,the empirical or semi-empirical correlations indicates that the proposed model is capable of predicting methane and carbon dioxide solubility in water and salt containing systems in equilibrium with their hydrate.The average relative deviations of predicted solubility for CH4 and CO2 in water coexisting with hydrate are 5.740％and 3.530％,respectively.When the proposed method is used for saline solutions,the average relative deviations of calculated solubility for CH4 and CO2 are 2.340％and 1.990％,respectively.The proposed model,therefore,presents potential applications for developing hydrate-based technologies in the fields of CO2 replacement exploitation and carbon sequestration.
关键词
气体水合物/热力学模型/溶解度/状态方程/电解质
Key words
gas hydrates/thermodynamic model/solubility/equation of state/electrolytes
维普
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