This work examines the use of the electrolyte Trebble–Bishnoi equation of state (eTBEOS) in predicting high-pressure phase equilibria in the presence of aqueous mixed-salt solutions. The eTBEOS combines the Trebble–Bishnoi equation of state with a Born energy term, a mean spherical approximation term, and a cation solvation term. Shortcomings in the originally regressed set of eTBEOS parameters are identified and discussed, and a new set of equation of state parameters is subsequently regressed for 58 salts. In order to extend the eTBEOS to mixed-salt systems, two approaches for computing the EOS parameters of the ionic species are investigated. The first approach uses the originally regressed parameter set plus parameter mixing rules, where appropriate, whereas the second approach uses the newly regressed parameters and no mixing rules. In the prediction of osmotic coefficients in mixed-salt solutions, the maximum relative difference between the experimental and computed values was 5.70%. For the gas solubility predictions, data were available for the solubility of CO₂, CH₄, and N₂ in a small number of mixed electrolyte solutions; the maximum relative difference was 5.79%. Finally, CH₄, C₂H₆, C₃H₈, and CO₂ gas hydrate formation conditions were predicted in a number of mixed-salt solutions, with a maximum relative difference of 10.76%. Overall, it was seen that both approaches allowed for comparable accuracy in phase equilibrium calculations. However, in the case of solutions made from salt mixtures with common cations, the second approach consistently resulted in improved accuracy.

中文翻译：

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将电解质 Trebble–Bishnoi EOS 扩展到混合盐系统，以及在汽液和固（水合物）汽液平衡计算中的应用

这项工作检验了电解质 Trebble-Bishnoi 状态方程 (eTBEOS) 在混合盐水溶液存在下预测高压相平衡的用途。eTBEOS 将 Trebble-Bishnoi 状态方程与 Born 能量项、平均球形近似项和阳离子溶剂化项相结合。确定并讨论了最初回归的 eTBEOS 参数集的缺点，随后对 58 种盐回归了一组新的状态方程参数。为了将 eTBEOS 扩展到混合盐系统，研究了两种计算离子种类 EOS 参数的方法。第一种方法在适当的情况下使用最初回归的参数集加上参数混合规则，而第二种方法使用新回归的参数并且没有混合规则。在混合盐溶液渗透系数的预测中，实验值与计算值的最大相对差为5.70%。对于气体溶解度预测，数据可用于 CO 的溶解度₂、CH ₄、N ₂在少量混合电解质溶液中；最大相对差异为5.79%。最后，预测了多种混合盐溶液中CH ₄、C ₂ H ₆、C ₃ H ₈和CO ₂气体水合物的形成条件，最大相对差异为10.76%。总的来说，可以看出这两种方法在相平衡计算中都具有相当的准确性。然而，对于由具有常见阳离子的盐混合物制成的溶液，第二种方法始终可以提高准确性。