Abstract The study of gas solubility in aqueous electrolyte solutions is important, e.g. for hydrate applications, and it is also a challenging task, as metal halide salts show salting-out effects on gas in water, while some quaternary ammonium salts (QAS) show salting-in effects. This work presents a modeling study of gas solubility in aqueous solutions of several QAS (tetra-n-methyl-ammonium bromide, tetra-n-ethyl-ammonium bromide, tetra-n-propyl-ammonium bromide and tetra-n-butyl ammonium bromide) with the electrolyte Cubic-Plus-Association Equation of State (e-CPA). The ion size and ion-water interaction parameters are obtained by fitting the experimental data of mean ionic activity coefficients and osmotic coefficients of corresponding binary mixtures. The results show that e-CPA can reasonably correlate the mean ionic activity coefficients of QAS in aqueous solutions. The ion-gas interaction parameters are obtained by fitting the experimental data of gas solubility and the results show that e-CPA can correlate the gas solubilities (for nitrogen, carbon dioxide, methane and ethane) reasonably well from a quantitative point of view. For example, e-CPA gives deviations of 9.2% and 5.7% for the solubilities of carbon dioxide and methane in TBAB, respectively. The salting-in and salting-out effects and the influencing factors are also studied.

中文翻译：

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使用 e-CPA 状态方程对季铵盐水溶液中的气体溶解度进行热力学模拟

摘要 研究气体在电解质水溶液中的溶解度很重要，例如对于水合物应用，这也是一项具有挑战性的任务，因为金属卤化物盐对水中的气体表现出盐析作用，而一些季铵盐 (QAS) 表现出盐化作用。 - 效果。这项工作介绍了气体在几种 QAS（四正甲基溴化铵、四正乙基溴化铵、四正丙基溴化铵和四正丁基溴化铵）水溶液中的溶解度模型研究。 ) 与电解质立方加缔合状态方程 (e-CPA)。通过对相应二元混合物的平均离子活度系数和渗透系数的实验数据进行拟合，得到离子大小和离子-水相互作用参数。结果表明，e-CPA 可以合理地关联 QAS 在水溶液中的平均离子活度系数。离子-气体相互作用参数是通过拟合气体溶解度的实验数据获得的，结果表明 e-CPA 可以从定量的角度合理地关联气体溶解度（对于氮气、二氧化碳、甲烷和乙烷）。例如，e-CPA 给出的二氧化碳和甲烷在 TBAB 中的溶解度的偏差分别为 9.2% 和 5.7%。还研究了盐析作用及其影响因素。甲烷和乙烷）从定量的角度来看相当不错。例如，e-CPA 给出的二氧化碳和甲烷在 TBAB 中的溶解度的偏差分别为 9.2% 和 5.7%。还研究了盐析作用及其影响因素。甲烷和乙烷）从定量的角度来看相当不错。例如，e-CPA 给出的二氧化碳和甲烷在 TBAB 中的溶解度的偏差分别为 9.2% 和 5.7%。还研究了盐析作用及其影响因素。