Vapor–liquid equilibrium data were measured for the carbon dioxide + ethyl n-butyrate (EB) binary system at high-pressures. Five isotherms are reported at (333.15, 343.15, 353.15, 363.15, and 373.15) K and pressures up to 121.75 bar. A static-analytical method with phases sampling was used. The new experimental results are compared with existing literature data and discussed. In order to provide a continuous and consistent description of the system phase behavior, unique sets of interaction parameters for different approaches with the Peng–Robinson (PR) equation of state (EoS) and classical van der Waals mixing rules were obtained. A constant k_ij value of −0.048 is recommended, providing an excellent description of the data reported in this work, especially for the liquid phase. Predictions are also compared with the other available literature data and discussed.

中文翻译：

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二氧化碳+正丁酸乙酯二元体系的高压相平衡

在高压下测量二氧化碳 +正丁酸乙酯 (EB) 二元系统的气液平衡数据。在 (333.15、343.15、353.15、363.15 和 373.15) K 和高达 121.75 bar 的压力下报告了五个等温线。使用了具有相位采样的静态分析方法。新的实验结果与现有文献数据进行了比较和讨论。为了提供对系统相行为的连续和一致的描述，获得了具有 Peng-Robinson (PR) 状态方程 (EoS) 和经典范德瓦尔斯混合规则的不同方法的独特相互作用参数集。恒定ķ _IJ推荐值为 -0.048，为这项工作中报告的数据提供了极好的描述，特别是对于液相。还将预测与其他可用的文献数据进行比较和讨论。