When designing extractive distillation processes, using selectivity and capacity at infinite dilution alone is hard to identify the real optimal solvent with minimal process cost. To overcome this problem, a new process-driven solvent screening approach is developed. As simple and reliable surrogate models, rational functions (algebraic fractions such that the numerator and the denominator are polynomials) and multivariate polynomials (a subset of rational functions) are trained to interpolate vapor–liquid equilibria with thermodynamic consistency. The surrogate models can directly be embedded into superstructure-based extractive distillation process design to obtain optimal solutions within a few seconds. This enables to evaluate the real process performance of numerous solvents efficiently. Incorporating the accelerated process design strategy, a multi-level solvent screening framework is proposed and exemplified for the separation of a close-boiling mixture ethylbenzene/styrene. The solvent C2H2Br4 ultimately enables a cost reduction of 27.9 % compared to the industrially used benchmark solvent sulfolane.

中文翻译：

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过程驱动的溶剂筛选，使用插值有理函数实现高效的萃取蒸馏


在设计萃取蒸馏工艺时，仅使用无限稀释的选择性和容量很难以最小的工艺成本确定真正的最佳溶剂。为了克服这个问题，开发了一种新的过程驱动的溶剂筛选方法。作为简单可靠的代理模型，有理函数（代数分数，使得分子和分母是多项式）和多元多项式（有理函数的子集）被训练为具有热力学一致性的气液平衡插值。替代模型可以直接嵌入到基于上层结构的萃取蒸馏工艺设计中，以在几秒钟内获得最佳解决方案。这样可以有效地评估多种溶剂的真实工艺性能。结合加速工艺设计策略，提出了一个多级溶剂筛选框架，并举例说明了用于分离密沸混合物乙苯/苯乙烯。与工业使用的基准溶剂环丁砜相比，溶剂 C2H2Br4 最终使成本降低了 27.9%。