The present study involved the experimental measurement of liquid–liquid equilibrium data for ternary systems consisting of water, propionic or butyric acids, and kerosene. The measurements were carried out at temperatures of 293.2, 303.2, and 313.2 K and 101.4 kPa. Distribution coefficients and separation factor values were determined within the immiscibility region, while the acid–base and Karl Fischer titrations were used to determine the mass fractions of the organic and aqueous layers. The type-1 LLE behaviors of the systems were confirmed by the cloud point method. The NRTL and UNIQUAC thermodynamic models were employed to fit the experimental tie-line data, and the corresponding binary interaction parameters were derived. Optimization of the binary model parameters was carried out using the MATLAB fminsearch function, and the resulting values were validated using GUI software.

中文翻译：

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T = (293.2、303.2 和 313.2) K 和环境压力下三元体系（水 + 丙酸或丁酸 + 煤油）的液-液平衡研究

本研究涉及由水、丙酸或丁酸和煤油组成的三元体系的液液平衡数据的实验测量。测量温度为 293.2、303.2、313.2 K 和 101.4 kPa。分配系数和分离因子值在不混溶区域内确定，而酸碱滴定和卡尔费休滴定用于确定有机层和水层的质量分数。浊点法证实了系统的 1 型 LLE 行为。采用NRTL和UNIQUAC热力学模型对实验联络线数据进行拟合，并推导出相应的二元相互作用参数。使用 MATLAB fminsearch 函数对二元模型参数进行优化，并使用 GUI 软件验证结果值。