Abstract Fitting liquid-liquid equilibrium (LLE) data to common thermodynamic models (NRTL, UNIQUAC…) has been proved in the past to be a non trivial task. Many times it leads to inconsistent solutions where the Gibbs stability criteria is not satisfied. In this work, a simplified parameter estimation problem is formulated where the Gibbs stability criteria and the minimization of experimental and calculated phase composition distances, are simultaneously applied. This formulation is intended to be implemented in general mathematical computing software. Five isothermal ternary systems are studied and the obtained NRTL binary interaction parameters are compared with both existing published parameters and those obtained from commercial data regression tools. Results show that the combination of the proposed problem formulation with commercial non-linear programming solvers improves the quality of the ternary fittings obtained.

中文翻译：

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从液-液平衡数据准确估计 NRTL 相互作用参数的简单可靠程序

摘要 将液-液平衡 (LLE) 数据拟合到常见的热力学模型（NRTL、UNIQUAC ……）在过去已被证明是一项非常重要的任务。很多时候它会导致不满足 Gibbs 稳定性标准的不一致解决方案。在这项工作中，提出了一个简化的参数估计问题，其中同时应用了吉布斯稳定性标准和实验和计算相组成距离的最小化。该公式旨在在通用数学计算软件中实现。研究了五个等温三元系统，并将获得的 NRTL 二元相互作用参数与现有公布的参数和从商业数据回归工具获得的参数进行比较。